Rough life you have!

Lady cleans your car like it’s a Roman sculpture and the payment is to take her on a cheap date?!

It’s definitely not much of a boost in FP, but probably enough to make up for the extra meter of line to push through.

I looked at my future pump yesterday and I don’t even know which way it flows lol!

I figured the small composite port is the outflow, but I guess that’s a riddle for another day…

one of the benefits of being an old man?
got rid of life's complications 20 years ago.
that was the rough stage of life.
getting the payback now.

i did do well on the labour exchange rate.
since i was having fun driving the 914 as a pay cheque.

she didn't want a drive of the 914 even though i parked it in a quiet part of the industrial estate in the docks and offered. but i have a feeling i am going to get the hard word put on me for a drive of the ute. she has never driven a ford being brought up a holden girl.
i don't know if that rivalry existed in the USA but here back a generation you either drove one or the other and nothing in between. the motor sport fans used to have beer can wars up on top of the mountain at bathurst during the big race and try and kill each other.

---

don't forget that they also used a smaller diam output hose to the engine as well.
pretty sure about that, but would have to look it up to check.
dunno if the SS kits do the variation or if they duplicate earlier year fuel line diams.

Tangerine has size options based on front or rear pump.

On this whole 914 project, I’m trying to maximize my purchases from the folks who built businesses based on keeping these cars on the road as well as members of the community.

Back on topic for this thread, I bought another TTS, this one is the Bosch part that is called for on the 928, but Porsche traces the PN back to the 912E.

I’ll test it and the fuel pump at the same time I guess. I’ve got the CSV pulled from the manifold so I can mist the engine again like a responsible 914 owner

Oh and Ford Chevy and Dodge are the competing truck brands from back in the day. Folks would make jokes or talk shit, but never serious.

umm, the 914 TTS just looks like a regular one they normally stick into the coolant circuit on most cars. must be sensitized way differently since its just parked in the air there above the crankcase? what about a kombi van TTS? didn't later air cooled bugs run L jet?
like the last of the mexican taxis. maybe they have them? and good enough to work well on 914.

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the ford/holden thing was not your trucks. it was your everyday regular mum and dad sedans and station wagons. the crowd on the hill at bathurst left civilisation behind when they went up there for the race. take your life in your own hands back in those days. all the guys who owned chryslers just stayed out of it. and if you owned a japanese car they would burn it. i think australia suffered from post traumatic stress disorder for at least 2 generations after world war 2. these days they are all so-fist-eekated global travellers with soft hands and drive hi-your-undies are compact suvs.

Tested the fuel pressure with the new wiring today and there is no improvement on fuel pressure build up.

Even though it’s disappointing, I’m glad the wiring is now correct.

At this point are we all in agreement that my excessive cranking time is due to the slow fuel pressure build?

Any thoughts on where to go next?

rebuild it as an AN with high compression pistons?

.......

or are you asking what to do next about not getting the bam start?

Lol... The latter.
But the former is on my list too. A little more compression is all this L-jet needs to really sing!

an AN on the twin carbs (lame solex carbs) had 85HP.
5 short of a USA 2.0L.
it must be possible to do an AN with L JET and hit 90 (at minimum)?

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try fitting an inline pressure check valve after the fuel pump.
relatively cheap to get hold of / easy to install.
might lose pressure over a week, but it could hold the pressure for a day or so.
give you a faster start throughout a day of operation at least?
think you have to have the fuel pump in stock position like i have to get the real bam start? and thats got problems that go with it for modern turbine pumps that i believe get worse that back in the day with roller cells. i feel pretty sure that the turbine pump i have is more vunerable to heat than the old one. one of a number of factors giving me strife on hotter days.

My car doesn't hold pressure for more than 20 minutes, not an l-jet I know, but I suspect it isn't the issue here. Have we gone and checked the spark yet? There could still be something causing weak spark.

my L jet will hold at 20lbs after around 6-7 hours. or did 2 years ago. from somewhere around 28 or so at idle. fuel pump in original position and brand new.

but i know what you are saying emery.
what else draws current. starter?

I haven’t. But that’s because the only thing left would be the coil and I figure it could manifest itself under normal driving, not exclusively on start up. Plus, it has its own wire again lol

I’ll measure it just to know… and since I’ve measured literally everything else on this car

Mike it takes a few seconds of cranking before I get above 28psi. There’s also no difference in time if I push the AFM flap and watch it build.

I do see the currently draw from the starter in the form of stair steps of fuel pressure building when I’m cranking. But again, no appreciable time difference to full pressure…. Both cases are slow IMO.

Just thought I would show you guys what happens when the aar is closed off on a cold start. Behaves quite a bit like low fuel pressure (as in when my pump didn't want to pump). Here are a couple of different starts. My djet cold (35 degrees) at 0 psi fuel pressure (first start of the day). Starts no problem.

https://youtube.com/shorts/q1JS-UG_yDo?feature=share

And then I close the AAR with my little custom troubleshooting device and try to start it. Finally,I open it back up again and do a cold start with fuel pressure.

https://youtu.be/8OJPwwWY_G8

Never touched the pedal during any of this.

Pfft!!! I wish mine started that quick

Question for the electrical guys:

On the dual relay, I have a jumper wire going from 88z to 88y; which is 12v directly from the battery. When I bought a new relay and replaced all the old connectors, I didn’t have a manual or wiring diagram so, I just copied the existing setup. Now I’m looking at it and I don’t understand the jumper.

Can someone explain what I’m looking at on this diagram vs the actual setup and the potential consequences?

yeah but i can hear your fuel pump priming before you turn the key to crank?
which is your little advantage with D jet.
your up to pressure when you crank even if you bleed down after 20 mins.
do one where you hop in and just crank straight away cold for interest sake.

my L jet starts almost identical to yours on a cold start.......after a week.
and there is no prime with an L jet.

and my second start of the day if i let it cool down (but the engine block will still be warmish and the aav probably as good as closed still?) is the bam thing your got with the tap shut. except mine keeps going. but its that quick. you were doing a super rich start that couldn't go forward?

i see van's got an electrical ? not my territory. though i can see what he has detected.
i've still got a headache thinking through his advancing timing at idle afr riddle.

@Van B
PS i somehow read a BMW forum last night.
its funny what you drift into.
L jet BMWs.
some guy had a what he thought was excessive cranking at startup problem.
lots of opinion. back and forth.
remedy was installing an in-line check valve after the FP.
he got a result.

not saying that is what it is here.
but he had a pump that would not hold any pressure after switch off.

apparently BMW used to sell a plastic inline check valve for $5.00.
now discontinued.
so he had to buy a more expensive aftermarket valve (probably higher quality).
he had a grizzle about that.
makes you think that BMW had a problem with fuel pumps and worked up a quick fix for a time when the cars were newer.

I don't think I could beat the pump. Tomorrow is another day though!

My AAR opens pretty much every time I start my car hot or cold. My engine runs incredibly cool, not the heads but the rest of it (375 is the hottest the heads get in cool weather, climbing hills 65mph in 5th gear, but that is still warm, haven't had my CHT gauge in temps over 60f yet). On a fresh cold start (35f) you are looking at a good 8 minutes of AAR. After the engine is warm, if I go into a store etc it will give me a minute of upped idle. Hotter the day, hotter the engine the less time but it is still noticeable.

I think a check valve is a good idea, but I’m not sure if I trust the rubber lines to live day and night at 30psi.
I need to do the ‘75 SS line diameter from tangerine and my new Bosch pump. Not sure how much faster it will build pressure, but I’m sure it will be a marginal improvement on what I have now based on the specs you posted a while back.

@Superhawk996 can I borrow your expertise to help my understand my wiring question above? I can’t understand why that jumper is there/was put there.

oh yeah @Van B.
thats a thought, 50 year old plastic fuel lines just sitting there under pressure silently.

we are all homing in on that 8 minutes.
your emprical evidence.
and some old kombi bus wisdom i dug up on a very old website.

Let me preface by saying:
1) I have not played with L-jet and/or the dual relay.

2) My car was a 73' D-jet so I have no parts for physical comparison.

After some scholarly study of the current flow diagrams for 74/75 L-jet just to understand how they are wired . . . . I have no idea why pin 88y and pin 88z would be jumpered.

According to the diagram you posted as well as the Haynes manual diagrams, I read this as within the double relay (J40) pins 88y and 88z are already internally connected and both would receive 12v power from the battery (A).

Is it possible that the double relay you have isn't the OEM 914 part and maybe the internal jumper between 88y and 88z isn't there?

You can do a continuity check between pins 88y and 88z with a DMM (remove the 12v battery feed 1st) to see if the internal continuity is there.

There would be no adverse consequence to the jumper since it would be a parallel path to the internal jumper. I'd get rid of it assuming the internal continuity exists between pin 88y and 88z. No point in a redundant external jumper.

@Van B

@Superhawk996 Thank you very much for the confirmation that I'm not losing my mind. The dual relay I have is the updated plastic Bosch part and not the old metal housing. But everything is the correct configuration. Now that I have the above diagrams I started looking at it when I did the fuel pump wiring just to make sure everything is correct, and that jumper was melting my brain. Granted I was begging the question a bit by concluding "there must be a reason", but as it turns out, I don't see a legit reason. The only possible explanation is if they aren't on the same circuit for this particular relay.

So, I'll give it the tone test with the MM before I cut the jumper, per your advice.

Thanks again,
Van

Can you post a picture? I'd love to see this.

Is the jumper a home brew add on or is the jumper part of the OEM wiring harness / plug connector? Could it be possible the wiring diagram are simply showing the jumper as internal even though it is part of the harness?

@Van B

Found this while Google'ing for pictures of the 914 double relay harness. Good general description of the operation and a re-drawn schematic that some might find easier to read. Be warned -- This is for VW Bus so not Exactly the same.


https://ratwell.com/technical/DoubleRelay.html

@Van B

Found this on Restoration Design site for 1.8L L jet. Looks like it has a jumper so maybe that connection between 88y and 88z is not internal to the relay as drawn in the wiring diagram.

DMM continuity check will tell you for sure.

Click to view attachment

I'm pretty sure there used to be a block plug on it, but when I bought the car it was block plug on the FI side and then individual wires on the main harness side. The plugs were all beat to hell and corroded so, I redid everything to make it all tidy.

I'll take a picture tonight and tag you so you can see it for yourself.

PS, that ratwell article shows the relay that I have. But his hand drawn diagram doesn't make sense to me. The numbers seem all wrong.

Picture will be great. I've always had 73's so no optics on L-Jet. I'd like to see it.

Agree on his numbering. I think what he was trying to do is to show that the dual relay could be replicated by wiring up two conventional Bosch SPDT relays. He's using Bosch conventional numbering for relay pins 85 & 86 are solenoid, pin 30 is the power feed. Strangely, he doesn't label Normally Open output 87. Likewise, he doesn't really help with specification of values for the current limiting resistor or the diodes. Numbers to the ECU pins will also be different because that info is for the Bus ECU. i found it interesting just for general info, and theory of operation. Good overview about how the L-Jet uses the dual relay arrangement to energize the fuel pump during cranking and then once running, how it "latches" via the Air Flow Meter circuit and how it deactivates fuel pump if engine stops running.

For me, I'm not a fan of the late model current flow diagrams. Yes, they have some advantages, but, I was taught by USAF to read schematics so those are easier for me to "see" the circuit. I think that was mostly why he drew it that way.

@Van B

had a look at mine @Van B

think we have that same black plastic relay.
i can't see any jumper wire on mine.
wires coming in but nothing that i can see looks like a jumper wire across.

bit hard to see and take photo of.
would have to unbolt it to get a good look.

best i can do with photos unless i unbolt.
thing is impossible to get a shot of.

there is a red wire, but as far as i can see at moment doesn't look like a jumper.
seems to feed into loom.

Click to view attachment
Click to view attachment
Click to view attachment

That looks like a jump wire to me. I’m home and stuffed with pizza so, I’ll go get my photo here in a few minutes. Mine is relocated to the edge of the battery tray so it’s easy to see.

@Superhawk996

Here’s the photo. Orientations are matched.

Are the connections able to be removed to see if 88y to 88z is internally connected?

If not, I'd just leave the jumper there and wouldn't cut it. From what I can see on Wonkipop's photo I think I also see a jumper.

That combined with the restoration design harness I found, I think that connection likely is external to the double relay despite how it may look on the wiring diagram.

At absolute worst (i.e. jumper redundant to internal connection), it is an extra 2" of wire that would be there for no reason.

If you can remove the connectors and do a continuity check between pins 88y and 88z that would be useful information to file as trivia but if it's working and hard to access, I'd just leave it.

@Van B

ok had to fire 50 rounds of ammo to get two hits.

this ones been on since 1989 at least.

Click to view attachment
Click to view attachment

@Superhawk996
I can check it no problem at all. I just didn’t get time tonight. Tomorrow for sure.
My concern originated with the fuel pump wiring fiasco. Basically, I started to question everything. I agree though, @wonkipop is showing a jumper as well. Which means my concerns are dissipating. The MM test will answer the hypothesis of whether the depicted bridge is internal or external to the relay itself.

@emerygt350
I thought you might enjoy some results from the fuel pump wiring.
I never got around to trying the timing light on the coil…you know, because I had a master cylinder that went all Kim Jong Un on me…
But I did a start last night in low 60F weather. There was still some cranking, but this time when it fired, it came straight to life vs that fumbling you saw on the video.

I think that change is almost certainly due to that shared wire the PO setup.

@wonkipop , I absolutely love this ‘87 BMW M5 AAV/AAR! I’m sure it’s not a mod everyone would want, but I get a solid 1400RPM on startup that lasts for 5-6min and then it drops slowly down to 1200 over another 3-4min. It will stay there for a loooong time if you don’t go drive, but by the time I’m out of the neighborhood, it’s a steady 900 and idling happy.

its on the money time wise.

i'd rather have 1400 rpm for 5 minutes than, ahh i think i will, i think i won't.
the saab one i dug up sounds promising then, assuming it still operates competently. got to do a pick a part run soon for the falcon so i'll be snooping around engine bays.

i didn't realise your mc had a weird haircut and chain smoked.

Touché’ good sir!

What I meant was that it got gout, became incontinent, and leaked all over the place!

@Superhawk996
Thanks for your time on this small mystery. I have confirmed tonight that there is NO continuity between 88z and 88y. Thus, the wiring diagram is reflective of internal and external configuration. go figure.

So glad to hear this has been figured out. And very happy to hear we have a replacement AAR in the works now. Is the 87 m5 the only car with it? Cause maybe 12 of those were sold. I hope it was shared...

Here, is the cold start 0psi with no pause you requested. I think it kicked on the 4th chug.

https://youtu.be/2mSMPQJAnL8

You can also hear me ignoring my children to play with my 914
So sad

great vid.

thats identical to my start after a week when i would probably have zero pressure. truth is its probably no pressure after a day or so. but i hardly ever drive it more than at weekends.

they start pretty good don't they.

That’s pretty good, I think.
In my last thread about the cold start issues, I recapped as you recommended some time ago. As expected there were many contributing causes I identified there. But at the end of that, when I knew I had it’s functioning as well as what starbear and Wonki described, that’s when I swapped the AAV. It gives me exactly what I was hoping for. A cold start like my 996.

What I’ve learned about the L-jet style AAV is that many are the exact same body, but with different valve shapes inside. Very few remain in production and I’m still not sure how standard motor products is selling a numbered Bosch part, but they are!
It doesn’t look like a reman either. The aluminum casting looks new, and that’s hard to fake.
Anyway, the bigger the engine it was meant for, the more air it flows. So, replacement of the AAV is actually a tuning opportunity so to speak. I went with a big daddy because of my goals. Getting one meant for a 2 something liter car would be a slight improvement over stock.

I’m still cranking more than him or you then. But it does light off with more purpose now that I’ve fixed the wiring.

I think a new fuel pump is the only thing that will get me to where you two are.

@emerygt350 where is your fuel pump?

Stock position, under the hell hole.

That has to be the root cause of my issue.

You know, I remember when I bought this car, I thought I was going to start with a suspension refresh and some cool wheels

yeah. thats why we can get the 4 crank start from zero pressure.
got to be.

Constantly learning something new about these cars and their quirks.

They do a similar thing on the relay board drawing. There is a jumper between pin 10 and pin 11 . . . . except it is actually in the 12 pin engine wiring harness. It's a whole lot more obvious in the relay board drawing.

Just made a note in my Haynes drawing. @Van B Thanks for taking the time to confirm that. Only a matter of time until that question pops back up again in future.

for your interest @Van B

dunno if you had already come across this. double relay demystified.

https://www.ratwell.com/technical/DoubleRelay.html


EDIT
i just got your member name to come up they way its supposed to!!