mangled air filter makes no difference to this scenario.
air filter is before the AFM!!!!
your problems are after it.
in airleaks. in the electronics. or the cuckoo clock analogue devices that mate with the electronics. its actually pretty dumb and quite accessible if you are methodical.
it will turn out to be simple. you just have to find it by careful searching.

you can suck in dirt for sure through a screwed air filter.
but....makes no difference to the current crisis.

read the stuff and get a grasp of L jet.
just a basic grasp.
you are an american. thats what americans do.
aussies just try and emulate.

then we can get cracking.
Van's your man to guide you through.

don't do anything random or think random thoughts.

if you are going to do this yourself you have to know what each element does.
its not that hard. if you ask me its more simple than a carb.
just work out what you think each thing does.
and ask questions.
get a grip on each part in the system.
just be an idiot (iggy pop claimed he was and look at him) and ask like an idiot if you have to.
no shame.

Thanks for the vote of confidence @wonkipop . I was definitely in that boat in Oct 21 when I got this car and you were one of my mentors then.

I know his AAV needs a good cleaning, but since it’s metered air, I still remain more perplexed by why it won’t take throttle?

@tshih914 . You should post a video so we can see and hear for ourselves.

Also, as a reminder, what do the plugs looks like? For each cylinder?

Car does not take throttle it stalls

Tried it before and after warming to operating temp. same result.

I only looked at plug under the snorkel it was running rich as I was cranking and cranking initially to get the engine to start (probably flooded until repeated cranking gave way to correct starting mixture.

I did not check for fuel pump running when AFM gate is depressed

so am i.

coud be the throttle position switch?
could be the distributor. not advancing? clagged points. etc
could even be some kind of ignition system / EFI harness gremlin?
could be further undetected air leaks he has not found yet.


@tshih914 needs to progressively eliminate items on the checklist but also take known items out of the system we have already detected that are defective and don't need to be there for now.

1. fuel pressure has been confirmed as in spec and good.

2. decel is defective. eliminate it from system for now. plug hoses.

3. AAV may not be closing. but is useful to start the engine when its cold.
as tshih notes its hard to start. start it. let it get warm for 5 minutes.
clamp the hose.

4. use the idle screw on the t/b to see if he can establish a low idle.
get it down to 1000 or slightly less if he can.
see if it will do it.

i've been doing a bit of reading up on this as you do when its a fault like this to see if owners of other early L jet systems installed in other cars have had this problem.

turns out its a problem in 928s.
Alfa Romeos. and BWMs.
but its not entirely clear, as is often the case, how its been solved.

i also haven't asked mike yet. and i will. he might have an insight.
wasn't much point until some diagnosis had been done.
which at least a little bit has been done now.

While I am trying to sort this issue out I am also in the process of rebuilding a 1975 2.0L engine with D-Jet to upgrade my 1.8L currently in my 1974 914. I am at the stage of doing the valve train and was looking for my engine tins #4 and 5. I found also the decel valve still attached to the end piece engine tin. So can that decel valve be used to replace the bad one in the 1.8LClick to view attachment

i think its safe to say your fuel pump has been wired to run off the ignition as a result of its modification to location at front of car.

the afm plug out test we got you to do indicated that.

if your fuel pump was wired to run off the afm it would maybe have started and run for about 10 seconds at most. and after that it would not have started.

yours did start and duplicated the behaviour of starbear and van's car.
both of them had the f p wired off the ignition circuit and f p ran all the time.

it will be a little hard to do the AFM test the workshop manual way if the fuel pump is already running. AFM flap won't make a difference. i hope that makes sense.

a better test for you to do is turn the ignition on but don't crank and see if you can hear f p running.

do the test anyway. see if with ignition on and pushing flap does anything.
like switching the fuel pump off? i mean who knows.

with those high idle revs you were getting as a result of the AAV and the decel valve,
and assuming the boot was ok between the throttle body and the AFM the flap would have already been being pulled well past its idle position. both those devices feed into the section of air intake above the throttle body which is closed at idle. so the only place they can obtain air is from the AFM intake. (or a leak in the boot).

onward. one item at a time.

EDIT
actually do the flapper test.
just to make sure the flapper is moving freely through its full arc and is not binding or catching anywhere. worth doing just for that check.

yes.
its the same decel valve in the 74 L jet.

may need adjustment though.

you can try it.
but for now i would just take the decel out of the equation and leave it out while we stay on the hunt.

i don't think your problem is a decel valve if you know what i mean.
thats not going to solve the issues.

whats going on with your car are several distinct problems over the top of each other.

we got rid of one of them. a faulty decel.

eventually when everything is sorted you can put a properly adjusted decel back on.
to me its the last item you would reinstall back on at the end of this.

as i have said. i don't even have one on mine and haven't for all the time i have owned and driven it. 34 years.

EDIT
the decel valve will not be attached to engine tin.
its in all cases mounted off the inner engine bay bodywork on rhs of car.
whats mounted off the engine tin is the fuel pressure regulator.
thats probably what you are looking at.
looks very similar to a decel valve.
esp the f p regulator on a D jet. it has an adjusting nut on it i believe that can make you think its a decel. the f p regulator on the L jet has no adjustment nut but is mounted on same place off engine tin on lhs like a d jet. its just a mounting nut on a L Jet.

@tshih914

where i would want you to go next is the throttle body and throttle body switch.

you have a new intake boot and a t/b gasket.
so to install those the t/b needs to come off anyway.

you can give it a good clean.
check the idle passage is clear.
and take the t/b switch off.
see how clean or dirty that is.
test it as per workshop manual.

lets make sure that is all tip top and working right.

The AFM could be bad. Send it to Fuel Injection Corp in CA to get it checked out.

he has a brand spanking AFM from fuel injection corp.
so unlikely its that.

but i would not discount it as a dud rebuild.
but doubtful.

if this is what you are talking about @tshih914 then its a fuel pressure regulator for a D jet not a decel.

Click to view attachment

@tshih914

i had done some snooping about with google searches.
(anything about L jet problems, including your car, interests me for purely selfish reasons )
i was going to ask my mechanic mike about this too.

read this article.
its specifically about Alfa Romeos fitted with L-Jet.
but it does not matter.
the systems are very similar across cars early L jet was fitted to.
go to section about electrical grounds.
i think he calls it step 2 in this article.
he specifically mentions the "starts and stalls syndrome".
not sure that is the problem you have, but perhaps it is.
others on 928 forums also refer to the "starts and stall syndrom" and lack of power when accelerating problem. which this kind of is. esp if we can get the high idle behaviour out of the picture and stop it masking what will be the pure behaviour of lack of throttle response/dies problem.

https://hpsimotorsports.com/blogs/tech-arti...nd-tune-up-page

i did notice in one of your earlier posts that the ECU in your car seems no longer to be bolted to the factory fixing off the battery tray and is instead floating about in the corner of the engine bay above the hell hole region. and its plug is oriented upwards which i don't think is ideal in terms of moisture entry. not sure how long its been that way in your car or whether you have it temporarily in that state while you have been doing this work.

i'd want to check that connection plug to the ECU.

have a read of the article for some guidance.

Click to view attachment

Click to view attachment

I have removed and replaced the AFM many times for various reasons - 3 operations. Undo hose clamp onto the intake boot, undo clips on air filter, disconnect AFM connector. On numerous occasions on starting the car up again I have found the car would start but dies when the throttle opens - WTF I have forgotten to replace the AFM connector again.

Your symptoms seem to be similar. This test could be worthwhile. I may be barking up the wrong tree but indulge me for a moment.

Will the car start and run with the AFM unplugged? If not, don't bother with reading further.
If so, how about starting the car and running the car with AFM connector unplugged and adding the gas and see if the motor dies. This may disclose that the problem is in the AFM to harness interface ie connector interface

If it dies, then start the car with AFM plug connected and (2 persons required) have one person open the throttle while the other jiggles the AFM connector plug and the AFM connector wires . The purpose is to possibly reveal a broken wire in the harness making intermittent connection or poor contact or corrosion in one or several of the 6 pins in the connection

Simple test and I may be way off the mark but worth a go. I feel yuor pain!

@nihil44

yep it could be the afm connector.

but what you need to realise @nihil44 is that you don't have a legit factory connection to how the fuel pump works either.
(and neither does our friend).
and we have done your test./or our test, the same thing.
read back a page or two.
the car should not run period with the afm disconnected if its legit original.
most it should do is run off the cold start injector for about 10 seconds and then quit.

but
"i'll fix vapor lock" etc.....and we are now in that!


so many of you don't have a legit system you can benchmark against the factory manual
50 years of "bogan" departures from the system.
the thing about it starting and then dying when you go the gas is not legit system,
or it is?, but you have to read it carefully.
its because you have a fuel pump which is not operating off the afm flap that the car runs at all.
if your fuel pump ran off the afm flap in the first place it would not run at all to even be in the space we are in.
see above.
but........that doesn't mean you are not close to the truth.


i think the problem connection could be in either of the plugs.
either the plug to the afm or the plug to the ECM.
or an earth problem.
or as you say the harness.
but thats not the reason yours quits when you gas it with the afm plug out.
because it should not even go with the afm plug out.
if that makes sense. yours quits whether the harness is good or not. or the connections and plugs. if the afm plug is out. because its artificially going in the first place like our friends. its being run when it shouldn't even run. in a stock L jet the afm runs the fuel pump. period. end of story. so to be accurate what is going on here is that something is not going right when the throttle body switch signs off on "i am finished with telling the ECU i am done with the idle circuit --- its all over to you and the AFM to tell the engine what to do". which is why you are right about the harness. or the plugs? maybe.
because there is still the distrbutor? one thing at a time?!

i must have one of the last fully intact L jet systems left.
i've never shifted the fuel pump.
the only thing out is the decel.
the rest of its factory intact.

so mostly i can do the trouble shoot and i am not getting misinformation from unaccountated for "improvements".

i think what i am trying to say @nihil44
is this.

we are on about the same thing.

if it was a legit factory L jet set up it would not even idle.
so lets leave that out of it.

its idleing. sort of. because its getting fuel. illegitmately.

and because it has a non legit L jet fuel pump power scenario it will idle.

-----
but as soon as you crack open the throttle it all goes to hell.
because thats when the ECU wants something more than the whatever the signal is from from the t/b and t.b position switch to idle.

and its not getting it?
because the plugs are dirty, the harness is farked or its not earthed reliably.

amongst other problems
because seriously. its all farked. the decel is farked up. the AAV is maybe farked up.
and why wouldnt they be. its 50 years old. you have to give it a break!
and help it.

further thought @nihil44 and @Van B

i reckon if this baby was OEM wired up it wouldn't even run the fuel pump and idle to even get to the point where it was stumbling when you opened the throttle.

so..........the hot rod set ups of fuel pump actually provides an insight?

i'm thinking back to his plug in/plug out afm test,
it did something.
but regardless the engine would run at idle?
and we know no way, unless either fuel pump gives fuel.
either provided by wiring.
or by AFM flap.
thats the only two scenarios it can run at idle and get fuel.

but once she goes on to throttle off idle stop it has to be AFM.
or its all over?
the fuel pump can be delivering fuel.
but the ECU expects information about how much air is coming in, air fuel ratio sincro etc.

Go to Bowlsby's web site and print his wire diagrams for Ljet. Get a test light and do a continuity check of the wire harness from the ECU plug. I had a bunch of cracked wires that I had to replace.

Wonkipop. I agree that the TPS may be an issue or even the ECU, but he’s got to solve the obvious issues first… control the variables. In general, people’s approach trouble shooting cars loke theres an OBDII port and a code to read. But we’re talking about an open loop vacuum system. And computers that are little more than if/then statements as code.

-Fix all potential vacuum leaks
-confirm baseline settings
-confirm fuel, air, spark per cylinder
-confirm timing (difficult to do at this point without a stable idle)

We’re doing a whole lot of talking in thinking without much information at this point. You already said it, @tshih914 has got to get methodical. Four pages into this thread and the airbox lid just now being removed is a SMH moment for sure.

Took the throttle body off to inspect and clean the mating surfaces and replaced the seal. The pin hole is clear of any obstruction and was attempting to check the plug harness for continuity at pins 2, 18, 2 to ECU. However the 2 10 mm bolts at the ends of the harness just spins freely without the bolt backing off. I suppose I have to cut the heads off inorder to get access to the pins at the ECU end of the harness.Click to view attachment

nuts do not release harness plug.

this is how you do it.
press down on the little spring clip.
this will release the bottom of the plug.
pull + swing it out from there, it will pivot on its upper hook connection.
once swung out far enough pull downwards off the hook.


Click to view attachment

all this is described in factory workshop manual.
have you downloaded it from the links i gave you back on page 1?
it will tell you how to do all these things without breaking anything.


the nuts hold the ECU into its support sleeve.
which should be fixed on to the edge of battery tray.
this does not seem to be the case with yours?
the ECU is just laying around in there?
the nuts have probably stripped the thread in the support sleeve.
the sleeve is made of plastic and is delicate.
EDIT, its been a while since i had my ECU out to clean around in that area.
i got the ECU out of that sleeve and i seem to remember those bolts are captured.
once you undo them a certain amount the ECU just slides out of sleeve.
i could be wrong, its been a while. but irrelevant to releasing the plug connector.

you missed inspecting the throttle position switch. TPS.
and testing it?
its connected to the underside of the throttle body.
checking whether you hear click of switch when you open t/b from closed.
but we can return to that.

take a photo of the ECU pins and harness plug when you have them apart and post it.

be delicate with it all. it looks like it might not have been off for a long time maybe.
so just go easy at it.

yes to all.

thats why i was keen for him to see if he could at least bring the idle down a little with the idle screw and the errant AAV and decel out of the picture and isolated.
its important to know if he can affect the idle with the screw at all and start to get something like a lower steady idle close or closer to normal.
or is the whole thing still being overwhelmed by another air leak that has not been found.

------

i think the TPS needs close inspection.
electrical test to see if its working.
and the mechanical test to listen for the audible click from the switch as the throttle is closed.
there is the ability to adjust its position with the fixing screws.
so that it can be put back in spec mechanically if its ok inside electrically.

they are vulnerable to filling with gunk as the car ages.
similar to the wear bushing problem of the throttle body itself.
the o-ring seal goes between t/b and TPS. lets condensed crankcase vapors etc gradually build up inside it if it can get in there.
its one of the faults of choosing a vertically alligned throttle plate pivot.
a lot of other manufacturers used a horizontally alligned throttle pivot with TPS off to one side rather than at bottom. a slightly friendlier position.

TPS must be fully ticked off.
its not a hard test to do.
you have to be able to trust each of these things by checking them one at a time.

we have to be sure the ECU knows when the throttle is closed so it can operate correctly on its idle circuit (or mode whatever you want to call it in one of these old analogue devices). .........as part of getting to a basic timing setting/adjustment.
we also need to know if the switch is doing its job to let the ECU know the throttle has opened. then we can trust it and move on.

Thanks wonkipop for saving my bacon and not butchering the ECU mount. I have followed your instructions and got the cable opened up without damaging it. I have also learned how to post a video on my Youtube channel https://www.youtube.com/shorts/HT8ScUYyYdw showing the throttle switch making the clicking sound for what its worth. Next I will use a ohm meter to check continuity of cable pin #3, 18, and 2 from throttle valve cable to ECU harness pin(which number pin corresponds to those connected to the valve?)Click to view attachment

I went to the manual and checked the wiring diagram which shows wires # 9, 20, and 17 which I think corresponds to pin # 3, 18, and 2 . Would someone provide the key for the pin position at the attachment point to the ECU for me to identify pins 9, 20 and 17.

thats great about the tps making the clicking sound.
it should do it just as you crack open the throttle and just as its closing.
sounds like its ok.
you can do an electrical test on it too.
to confirm it all.
but it sounds like you can tick that off.

i'll have a look later and see if i can find the pin diagram for the ECU and post it.
with a bit of luck someone else might post it for you before i get hold of it.

Jeff Bowlsby's excellent website has a "914 Tech Notebook " section.

https://bowlsby.net/914/Classic/TechNotebook.htm

The ECU Connector pin-out is on page 22 of the "Technical Manual L-Jetronic Fuel Injection System".

Hope this helps,
Bob

ah good.
@bob164 has given you the links.

in case you can't stumble on it.

here

Click to view attachment

Click to view attachment



BTW i always had the battery disconnected when i pulled that ECU plug.

by the way i think i have had a thought about how this thing is actually running.
@Van B can offer his criticism on my ridiculous idea?
or any one else for that matter.

i don't think its starting and going to "idle" with the usual assistance of say the cold start injector etc. ie a normal start to a fast warm up idle. hence the hard starting.

nor do i think the original description of high idle at 3000 rpm is correct.
thats not an idle. thats what we used to call an engine that was "racing".
its half way to red line!!!

i think this thing might actually have been permanently in the twilight zone of thinking it was deaccelerating. with enough cranking, it sprayed enough juice in there to finally fire.
and once it fired with all the air it was getting from the faulty deacceleration valve and AVV it went straight to stuck wide open decel valve mode. 3000 rpm and stayed there.
because it can? there is no fuel cut off at throttle close off from high revs in an L jet except via the AFM flap. and if fuel cut off does happen it only happens if the afm flap descends past the point where the contacts are to activate the f/p. (why the decel is there in an L jet in the first place, to stop that). i put a proviso on that of course, it will only cut off the fuel if the fuel pump is properly wired to AFM control as it is stock.

i'll think more about this.

but in summary so far.

car:

1) starts with difficulty. (something is amiss in the cold start set up).

2) when it starts runs in jammed decel mode with tps indicating idle position and communicating closed throttle but AFM flap at elevated point on arc of contacts.
(which is a perfectly legit situation for L jet - although usually only momentary ).
its kind of a zombie?

beyond that i can't think whats going on when you try to gas it.

everything has to be properly set to really test transition to opening throttle.
valves adjusted.
points. timing (including dist advance function checked).

we know its got legit fuel pressure.

anyway its just a thought at this stage and further testing of components has to be done.

the cold start injector and the thermo time switch that controls it need checking in relation to hard starting.

I tried to check the wires from the throttle valve switch pins 3,18,and 2 for continuity at the 2 ends (ECU and valve) as shown in the 3 photos. Meter set for audible beep and there was no sound. Am I doing the test correctly?

photo below testing pin #2 to #2 on ECU end

Between pins #3

testing pins #18

Click to view attachment

you operate the throttle while doing the test.
and thats

1) testing the switch itself.

and then

2)
if you want to test the connection to the ECU you need that plugged back in and test it at the ECU plug pins.

is that what you are doing?


--------

@Van B

i spoke to mike this morning.
as i thought the AFM will run the engine according to where the flap is and the ECU will provide the fuel, no matter the throttle switch saying its in idle.
it accepts the inputs. despite the real throttle being closed and the psuedo throttles open (the decel and aav). both of these are acting as "metered air".

he doesn't think that is why it stumbles when you open the throttle.

[quote name='wonkipop' date='Mar 8 2023, 05:17 PM' post='3063545']
Click to view attachment

you operate the throttle while doing the test.
and thats

1) testing the switch itself.

and then

2)
if you want to test the connection to the ECU you need that plugged back in and test it at the ECU plug pins.

is that what you are doing?

Initially , no. When I did as you described the throttle switch test pass when the throttle was opened sufficiently for there to be continuity between pins 18 and 3.

2) when plugged in there was continuity between pins 2 or 3 with 18when throttle is fully closed.

here is a y t vid i came across a few years back on t p s for L jet.
he opens one up so you can see how it all works.
including the type that is on the 914.

https://www.youtube.com/watch?v=WHoeE81ZcHU

Our TPS really only tells the ECU to send fuel for idle, neutral for driving range, and then enrichment for wide open.

The inside of my TBS is reasonably clean and it passed the test of throttle opening resulting in 0 ohms resistance when throttle is opened. So the racing/idling at 3000 rpm with throttle fully closed is indication of what's not working correctly?

What component should we test next?

CHT

cylinder head temp sensor.


after that pull the AAV off. Aux Air Valve.
clean it out. carb cleaner is good. get it thoroughly cleaned out.
probably full of gunk.
put it in the freezer/cold fridge for half an hour after you have cleaned it.
see if its (EDIT) open. you look down the bore and hold it up to the light.
if it is (EDIT) open hook it up to a 12V source. like a car battery for instance.
after 5 minutes or so on the current it should be closed. or very nearly closed.
hold it up to the light again and inspect to see if thats the case.

basically you should be testing everything on the EFI.
everything.

then the ignition. in particular the distributor.

you need to be sure everything is working.

while you wait to get your hoses and seals.

the ECU is the hard one to really know.
you still have not answered my question.
how long has it been lying around loose in the engine bay.
the plastic sleeve you almost went hammer and tongs at provides it with an isolated mounting so its never lying on anything hot or subject to random electrical shocks etc.
?


we have already explained to you why it was racing at 3000 rpm.
its pulling air through the decel valve and the AAV.
this is metered air, not air leaks. ie those malfunctioning components were pulling the afm flap open just the same as if you had the throttle opened.
you (or someone before you?) had screwed the throttle idle screw right down hard closed to try and calm it down. your car has never been idling in that state.
its been racing with a psuedo throttle open.
the timing is probably out. etc.

what we don't know is why it stumbles when you open the throttle.
although there was a clue when you did one of the tests i suggested to close off the decel and AAV hoses and you reported it almost did not stumble over when you opened the throttle. unless i misread your report.
this might offer you some hope.
i could guess the stumbling might be in part antagonised by some further genuine air leaks in the system. ie air which is not pulling the flap open in the AFM but causing the mixture to lean out. but i am really not sure. its impossible to know until the entire system is verified. vacuum hoses, seals and all. its always been my experience that unmetered air leaks do not cause the engine to race, rather they cause it to be unstable and unsteady at idle and often mean it just dies and won't run.

the point you need to get to is a proper idle and a proper cold start.
by proper idle i mean an idle set off the t/b idle screw and with the ignition timing verified and properly set. thats step 1.
and you won't get there until you go right through the system.
by the end of it you will know every bit and what it does.

Wonkipop, you meant open on the AAV when you put it in the freezer. Then closed when it warms up. Even if the heating element is bad, this AAV is still good about closing when the engine warms it up. But the spring does get tired and won’t open all the way anymore… unless it’s gummed up.

Otherwise, based on the neglect while sitting for years. I guarantee the injectors aren’t working either. Bad spray pattern or too clogged to increase flow are very probable issues.

But what I said in post #120 is still my opinion.

ah sh$t.

sorry. i meant that. dyslexic today.

i agree with post #120.
and more.

@wonkipop

The ECU was not left dangling loose in the engine bay. It was securely mounted to the rubber mat on the firewall by a long screw into the firewall so I believe it is not damaged.

I did notice the CHT was very rusty and probably needs to be replaced. I think it is a thermocouple resistor that register about 300 ohms when cold and resistance goes down when hot. Checking it is just a matter of measuring the resistance at the two ends (head of the part that screws into the cylinder head and tail of the wire leading to the ECU harness)

I have received the hose kit and am in the process of removing the AAR and cold start valves for testing and cleaning. That hose kit does not seem to have the right number of hoses or some of which are too short to replaced those currently in my car.

ok thats good about the ECU.
makes me look less sceptically at it in photos.

sounds like you got a bit of momentum up now.
good luck with testing and checking all the bits.

did the hose kit come with a guide drawing for each hose?
would be unlike AA to have that wrong i think.
list up anything specific you encounter with a photo and perhaps we can check it against what should be there and where they go.
you will find my hand drawn hose diagram is accurate, its off an original cond car.

@tshih914

you might wonder why i am touchy about ECU's

a little story.

got a friend of sorts who owns a late 90s BMW M3.
who has had a saga that has lasted 5 years.
for some reason two decades ago he bought one of the so called "clutchless"manuals.
early tech.
not a paddle shifter on steering wheel but you flick the gear lever version.

anyway.

it started sh#tting itself after you shifted gear.
went into 3 cylinder limp mode.
for a while he got away with switching it off and restarting.
but it just got worse.

when the BMW "i am a cripple" business started, our resident mechanic mike,
said - "its the ECU".

the owner grinned and decided not to take the advice.

5 years later, having done everything, and having taken advice from every dickhead under the sun, at the BMW club, the alfa romeo club etc and so forth, having replaced oxygen sensors, rebuilt the vario cam unit whatever its called on a BMW, etc etc etc etc - having searched every BMW forum on the globe to get opinions, he finally found another BMW "REAL expert" from the era who was retired. guy said the same thing as mike.

"ECU mate"

and then he contacted BMW to get one.

they said. "lucky fer you mate, ve haff vone left".
one in the entire world.
(because its a special ECU for the dumb arse flick shift clutchless manual).
rare as hens teeth because no one else was stoopid enough to buy them.
most sane punters bought the three pedal fully analogue version.
its better.
but don't say that to my "friend".

anway - so he got it. all special delivery from germany.

and some tech experts here at a special BMW workshop hitched it up to his engine and did some keyboard work etc and.......it goes.

but thats it. he is farked if it happens again. there are no more ECUs for that pile of bavarian excrement. (please excuse my negative opinion of german gum tree magnets).

---

in short what the original ECU was doing was cutting to 3 cylinders to accomplish the shift, because thats how high tech its low tech was. but then it could not reconnect to all 6 cylinders after the shift. so it was stuck in the zombie world of half way through a gear shift.

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now a 914 ECU was built to survive on the surface of the moon. its seriously over-engineered. military grade. but its half a century old. i'm sure bosch would be both astonished and smug at the same time that these things are still going.
but you know the older they get the less tempted we should be to subject it to conditions equal to a straffing pass on an afghanistan mountain hide out for el quada or a bomb drop on bagdad.

The ECU is very obviously not mounted to a rubber mat, on a firewall, with long screws.

I went to check the CHT sensor (which is really difficult to get to buried under engine tin near spark plug #3) Just measured the resistance from the connector rectangular plastic piece to engine ground and it read 1.77kohm. I don't know what that means as I expected around 300 ohms cold. Will check once the new part comes in from Amazon.

The next thing I did was to remove the AAR and sure enough the valve is open when cold. However when I connected 12V to the 2 pins at the connector after 13-20 min the valve felt warm to the touch but the opening did not close so that valve is broken.

Also in looking at the valve there appears to be a post for grounding wire/connector? that was not attached to anything.

Click to view attachment

Might want to squirt a few drops of silicone spray in there just in case that loosens things up a bit. Worked on mine which was mostly working but needed a little encouragement to behave.