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Posted by: GregAmy Aug 7 2016, 09:43 AM

Nice beautiful New England Day, heading off to the Manchester CT car show and...car won't start. Cranks, a few cylinders fire, then it dies. I cycle the key and hear the pump running and then stop (as before) and same thing: spits then dies.

I tried cycling the key a few times, with the mindset of building more pressure, and it spits a few more cylinders then dies. Even got it to rev a little bit with a half-dozen key cycles, but always dies.

Only other symptoms is that I noticed the last time I drove it earlier in the week it was dying when I put in the clutch. Was not consistent, only did ti a few times, but that was unusual behavior.

Stock 2L fuel injection, but with cold start and idle air bypass systems disabled; been running fine like this for the several years I've had it.

Checked all the relays, each works with the heater blower. Swapping them makes no difference (which I expected, given the pump cycles with the key). My guess is that however the pump is supposed to continue to run after releasing the key, it's not getting the power it needs (just a guess, I've not gotten under there with a voltmeter to verify). The wiring diagrams are not clear (to me) how that power is applied to the fuel pump relay.

Any way to quickly salvage my afternoon trip to the car show, or am I using my beautiful afternoon to swap the street car onto the lift for extended diagnosis?

40-yr-old electrics, gotta love 'em.

- GA

Posted by: GregAmy Aug 7 2016, 10:01 AM

So I removed the relay panel harness connector, the one that I think goes to the computer, cleaned it and put some dielectric grease on it...and it starts.

But do I trust it? Well, I do have AAA...

Can anyone explain the control functions of the fuel pump on the D-Jet?

GA, here we go...

Posted by: The Cabinetmaker Aug 7 2016, 12:17 PM

Its all in the Brad Anders website. Brads 914 2.0L page.

Posted by: GregAmy Aug 7 2016, 12:54 PM

Made it to the show and back, but it was cutting out on me on the highway, so there's clearly an outstanding issue. When I got home I wiggled and tapped everything - relays, plate, fuses, wiring harness - and it didn't die.

Electrical problems, yay.

I'm guessing you mean this? Thanks for the reference. However, I'm not getting any info from that page except for the intro.

http://members.rennlist.com/pbanders/FPChecklist_frame.htm

Posted by: The Cabinetmaker Aug 7 2016, 12:58 PM

Go here

http://members.rennlist.com/pbanders/DJetParts.htm

Posted by: boxsterfan Aug 7 2016, 01:18 PM

Stock pump in stock location on stock wiring?

If I recall, turning the key on will allow the pump to run for a few seconds before it turns off. Of course, if you are cranking the car to start the pump is to keep running.

Definitely sounds like electrical issue. Perhaps check all of your chassis ground wires. 40+ year old wires are not fun to troubleshoot. That pbanders site is the best D-Jet reference on the planet.

Other oddball stuff to look at (just throwing these out there):

1. Distributor/coil setup- You getting spark consistently?
2. Cracked relay board (you'll have to remove it and have a good look).
3. Voltage regulator issue?

Best of luck.

Posted by: GregAmy Aug 7 2016, 01:36 PM

Thanks. Do you know if "19 and relay plate terminal III (white plug, back left corner) - ECU control line for the fuel pump relay" is hot all the time that the car is running?

Edit: disregard. Anders links to a discussion of the ECU and cofirms that as long as the engine is above 100RPM the pump relay control circuit is powered.

http://members.rennlist.com/pbanders/ecu.htm

Posted by: GregAmy Aug 29 2016, 10:16 AM

Ok, so maybe this thing isn't worked out yet...

Fuel pump is priming with ignition on, so at least that's resolved. However yesterday I took it for a nice long drive, started/ran fine, no hiccups. However 3 hours later when I went to leave, it started fine (fuel pump primed) but then it kept dying. Thinking it was the lack or AAR and cold start valve, I could kinda keep it running with some throttle, but it was not running smoothly; it would have a random hard miss, and would try to die.

I was following someone to the next stop and it was driving terribly: I mean HARD shutoffs and restarts, not like a dead cylinder miss but like a shut off engine miss. It would die when I came to a stop but would kinda restart, and I could keep it running with some throttle but still not smoothly. As I'm cruising down the road it was HARD shutting off then coming back on, and feeling overall unhappy (like a flooded spark plug) slightly less so with full throttle but it never went away. I thought at one point I was going to have to pull over but kept going, and then...

...all of a sudden it smoothed out. No problems for the rest of the 30-minute trip. Car ran fine and smooth and never stalled again.

Starting up 2 hours later cold, same problem: starting and die, could keep running with throttle but very un-smooth, like a flooded cylinder. I let it warm up for a few minutes and it got better but when I hit the road I got those hard stalls and restarts, and then...

...it warmed up and it was fine for the rest of the trip.

I had these same symptoms that last time I drove the car a few weeks ago, before I replaced the relay plate. I thought it was related to the bad relay plate, that maybe the fuel pump was shutting off. I've replaced the plate and the relay, and it's still there.

I'm stumped, even more so because it seems to be related to the temperature of the engine. Dead cold the problem is not there, partially hot it's there with a vengeance, completely warmed up it's gone.

I've checked the head temp sensor and it's within book range, cold and hot.

Ideas appreciated.

Greg

Posted by: Sleepin Aug 29 2016, 10:24 AM

Fuel pump? Sometimes when fuel pumps start to fail, they will intermittently operate. This happened to me on the way to RRC a couple years back. I called SLITS (I'm going to miss being able to do that) and he suggested direct wiring the pump to the battery as an emergency fix, then gave me the NAPA part number for the replacement pump. Sure enough, it worked fine for a while (hour or two) being directly wired up. Once I replaced the pump, all was fine once again.

*note...you get funny looks driving down the road with jumper cables running from the battery to the front trunk (1975 model).

Posted by: BeatNavy Aug 29 2016, 10:33 AM

Sensor itself may be fine but what's the condition of your wiring harness? I'd look for kinks/breaks that can create open circuit intermittently from CHT to ECU. Inspect the actual connection closely. I have experienced bad CHT symptoms when it was the wiring harness not the sensor itself. One reason I bought one of Jeff's new wiring harnesses...

Like others have said - it sounds electrical - like a connection is sketchy somewhere (CHT, MPS, T1 Sensor, etc.) that's making it either run too rich or completely cutting off (e.g., fuel pump) when it acts up.

Posted by: 76-914 Aug 29 2016, 03:48 PM

I'm going to suggest that you install a FP pressure gage. If your CW and don't want to add one to the interior portion you can install a mech FP sender/gage in the engine compartment. It greatly improves diagnostics when you can rule out a major (fuel) player. Also, try jiggling your ignition key next time it happens to see if there is a change.

Posted by: GregAmy Aug 30 2016, 05:56 AM

Thanks for the tips.

I don't think it's the fuel pump itself. I replaced mine a couple years ago with a 2-port NAPA pump/kit I got from Chris (Tangerine) so it's probably OK. Plus, it's correlated to temperature of the engine and there's not a lot of temp change up there (it's mounted under the tank).

Wiring I can certainly understand. One easy trick I can do is run some wire from the power terminal on the pump to an LED in the cockpit and see if I get a flickering light correlating to this problem. If I do get a flickering then I can move the wires back to the replay board, both output and relay control, and try to nail down where the prob may be.

As for the head temp sensor...man, trying to troubleshoot a random problem there will be damned near impossible. Is it correct that the fuel injection shuts off if it doesn't have a good temp reading? If not, what are symptoms of a bad sensor/circuit there? Jeez I hate 40-yr-old wiring. But can't float the cost of a new harness right now.

I have four race weekends in a row coming up*, so this is going to be an October project. Thanks for the advice.

- GA

* LRP Historics (driver observer), SCCA Regional at Palmer (914 race car comes out for the first time), and Mid Ohio SCCA Runoffs (competing). If you're in the area at any of these stop by and say hello, #33 STL Honda Civic Si or orange 914

Posted by: Philip W. Aug 30 2016, 06:41 AM

I might suggest the MPS failing - I had this exact scenario last winter and it ended up being the MPS, - and it held vacuum, its diaphragm was not torn- it was failing electroically - I have a A/F meter- it was failing LEAN not rich like the usual default, so it would do the same thing you are seeing- but yes a CHT circuit shorting out will do this and if the #3 plug wire is close to the CHT wire it can cause interference as well. , - but if I had to guess ? 1. MPS, 2. CHT 3. your grounds for the FI at the back of the case- I had this happen this spring they were vibrating off - and all of a sudden running on 2 cylinders- so check those- I soldered mine on so they would quit coming off and I have a fairly new harness from Jeff B- also #4. check the tightness of the injector connectors they loosen with time - had this happen to me on my way back from Manchester 2 weeks ago after picking the car up from Chris. - Jeff Bowlsby posted a picture on my thread about how to tighten these.

- some times the only way is to do the process of elimination - but one thing at a time- try a spare CHT, or MPS first. - and I now have a Pressure gauge in line so I know if the fuel pressure is exactly where it has to be.- my pump recently went out or was on its way out- 5 years old napa pump, but it was still running but making a ton of noise and so I replaced it cause I had a spare Bosch in the shop- like night and day - Good luck, looking forward to hearing which issue it is! oh the fun of 40 year old cars and parts!!!!

Phil

Posted by: Shadowfax Aug 30 2016, 06:49 AM

What type of plugs are you using and what is their condition? I suspect one or more could possibly be fouled.

Posted by: BeatNavy Aug 30 2016, 06:49 AM

No, a bad circuit there is interpreted by the ECU as a cold engine, and it lengthens the pulse for the injectors thinking it's a cold condition. On a warming or warmed up engine it effectively floods the engine and kills it. That's my understanding anyway.

I agree with Phil. Take each component you can think of and test it individually as well as its actual circuit to the ECU. The more suspects you can rule out, the better you can focus on finding the root cause. Test/inspect FI grounds, Trigger Point connections, etc.

Testing the MPS electronically is very simple with an ohmmeter. If you have the vacuum pump, that's an easy enough test too.

Posted by: injunmort Aug 30 2016, 05:13 PM

fuel sock and fuel filter, first.

Posted by: GregAmy Sep 4 2016, 07:53 AM

Another data point.

I was considering hitting the Lime Rock Historics car show today, figured I'd let the 914 decide if we were going. The 914 decided we're not going, it would not start.

Fuel pump cycles with the key, car cranks fine. After a couple revolutions it briefly fires, then dies. I can continue that for a seemingly infinite number of key cycles: key on, pump on, crank, briefly ignition for a few cylinders, dies.

It's not the fuel pump circuit. I jumped between 30 and 87 on the relay plate and the fuel pump is audibly running, car does the same thing: briefly fires then dies. I can also smell fuel so I'm confident I have fuel flow/pressure.

I'm thinking either ignition or something in the engine management. No motivation to deal with this until October. I momentarily considered driving the licensed rollcaged 914 2L race car to this event, but an hour-and-a-half on a race suspension and 13-yr-old Hoosiers just didn't appeal to me. I'll play with the race car next weekend at Palmer (it's getting replacement tires before then).

-GA

Edit: I have neither a spare MPS nor spare CHT sensor to check, so this will need to wait until another day.

Posted by: GregAmy Sep 4 2016, 02:54 PM

OK, I lied, couldn't stay away from it. Since I didn't make it to the car show I got the race car prepped and loaded and hit the street car again.

I asked my wife to crank the car over while I shot it with starter fluid, and to my surprise I can keep it running that way. However, stop delivering it the ether and it dies.

I don't have immediate access to a fuel pressure gauge, but I disconnected the fuel delivery pipe in the engine compartment and jumped the fuel pump, and it's delivering a good stream of fuel into my fuel jug.

To remind, I also jumped the fuel pump and tried to start it, same behavior. At this point I'm convinced it's not the fuel pump or control circuit.

How does this affect our thought process? What other failures in the engine management system would cause brief spurts of fuels then lack of fuel delivery?

Man, carbs and basic solid state distributor ignition sound so nice right about now...

Posted by: GregAmy Sep 4 2016, 03:24 PM

And more randomly-chucking darts toward a blank wall...

- Disconnected MPS hose and plugged, same behavior.
- Reconnected hose and disconnected electrical connector, same behavior.
- Disconnected TPS electrical connector....car started!

Wha...?

- Reconnected TPS electrical connector...car started.

<shaking my head>

- Let car warm up - recall I don't have the air bypass or cold start hooked up - and disconnected the CHT sensor, engine died.

- Restarted and disconnected the intake manifold temperature sensor, and the engine note picked up a few RPM and seemed to run a tad smoother.

I replaced the TPS board with a Dave Sprinkle unit a couple of summers ago, adjusted with a spare TPS plug and an audible ohmmeter...rechecked it just now and it's fine.

I'm stumped. Is this a component failure or am I dealing with some kind of gimpy wiring harness problem? Don't have the bucks for a new wiring harness just to try it out...dammit.

Posted by: injunmort Sep 4 2016, 04:19 PM

i am starting to suspect a duff coil and just for cheap yuks, replace the condenser. both fine sources for intermittent ignition problems. since you have verified consistent fuel flow.

Posted by: 76-914 Sep 4 2016, 09:04 PM

Fuel pressure. Well I'll be. As far as the intermittent ignition problem; double check that the molex plug on the dizzy is clipped in place, both ears.

Posted by: GregAmy Sep 4 2016, 09:17 PM

I don't believe it's an ignition problem. Recall that I wrote I could keep it running with starter fluid or brake cleaner but it wold die when I stopped spraying. Further note that I demonstrated the fuel pump is running and flowing fuel, and that with the fuel pump jumped on constantly it still would not start.

It's a fuel delivery/engine management problem, either component failure and/or wiring problem.

Posted by: GregAmy Mar 9 2017, 03:34 PM

Aaaaand it's back. After starting and running perfectly fine yesterday for a couple hours.

Nice-sounding carburetors are looking miiiiiiighty tempting right now.

Posted by: GregAmy Mar 9 2017, 04:29 PM

Ok, yeah, this thing is really pissing me off now.

- Car won't start. Turn on key, hear pump. Cranks, brief fire, then dead cranking. I smell fuel.
- OK, maybe fuel pump isn't staying on during crank, so I jump the relay, pin 87 directly to battery. Pump on, hear fuel sloshing through the return.
- Cranks, brief fire, then dead cranking.
- I remove each electrical connections I can get to easily, one-by-one: TPS, temp sensor, both large connectors to the relay plate, each relay individually. Try cranking after each: Cranks, brief fire, then dead cranking.
- After doing each one-by-one, ensure terminals are clean, wipe with dieletric, ensure proper secure connection, try cranking after each: Cranks, brief fire, then dead cranking.
- I ask my wife to briefly join me in the garage, sit her in the driver's seat, ask her to try and start it. Cranks, brief fire, then dead cranking.
- I ask her to try again, but this time I remove the air cleaner and snag some brake cleaner to spray into the throttle body as she tries to start:

Cranks, fires, then runs.

I keep it running by hand (as well as one can do without an AAR) and the engine continues to run after I stop spraying brake cleaner in the TB. I keep it running until it warms up, and ask her to turn it off, and retry.

It starts and runs.

I just took it for a ride around the neighborhood, starts and idles fine (it's warmed up now). I get home, shut it off, it restarts and runs.

I have no idea what is wrong with this thing.

Posted by: Porschef Mar 9 2017, 04:52 PM

Sure seems like fuel. Sounds like your pump is running.

Filter's clean?
Pressure's good?
How bout them injectors, are you getting a proper flow? Those drove me nuts on an engine that sat for a while...

HTH

Posted by: GregAmy Mar 9 2017, 05:14 PM

I'm not convinced it's fuel pump or pressure. Filter's clean (both it and the pump are new) and I removed the line last year in the engine compartment to check the flow into a dump can, and it was "quite brisk" and I couldn't stop it with a thumb (made a mess trying). But I'll break down and buy a pressure gauge and leave it in there for the next time the car decides it won't start (because I guaran-damn-tee you it'll be fine for the next half-dozen times I try.)

Dunno about the injectors, but the car runs fine - when it runs.

It's something binary. And dirty injectors and a bum fuel pump or clogged filter are rarely binary.

Sure wish Cardone still reman'd those distributors. I'd love to replace points and condensor (both a couple years old), and trigger points and have it all nice and clean inside.

Posted by: ThePaintedMan Mar 9 2017, 05:26 PM

I had a similar problem, but in a more modern car. Turned out to be bad plug wires, though aesthetically they were great.

I also have seen a similar scenario on an L-jet 914 and it was a bad CHT.

Posted by: 76-914 Mar 9 2017, 06:15 PM

Greg, just for "shits n grins" check your dizzy cap coil contact pin. You know, the spring loaded one in the top center of the cap. Be sure it hasn't worn down past the limits.

Posted by: GregAmy Mar 9 2017, 06:22 PM

Thanks for the tips; keep 'em comin'!

I re-checked what Tangerine did when I left the car with him after I bought it, he only noted "Engine Tune-Up, Adjust Valves, Set Timing" but no points/condensor on the parts list. I think the car is well due for that and possibly some wires and plugs, and I'll toss in a Bosch distributor cap and rotor while I'm at it.

Advance Auto seems to think they can get the Cardone distributor. I'll give 'em a shot at it and remove any possibility of the trigger points being an issue.

I tested the CHT sensor last summer per the book, and values were within range both hot and cold.

And I'll buy a fuel pressure tester.

This is one of those problems that is seemingly random, leading me to lean toward something electrical. I hate to get into just replacing parts, but that's about where I think I am right now...

Posted by: Dave_Darling Mar 9 2017, 06:57 PM

How's the fuel pressure? You've been kicking with this a long time; it is worth knowing what happens to the fuel pressure when the engine dies.

Could it be a kinked supply line somewhere? That would give you very low fuel pressure. How about a clogged inlet in the fuel tank? Low pressure after a little while.

What does the pressure do?

--DD

Posted by: GregAmy Mar 11 2017, 10:18 AM

And OF COURSE it starts fine yesterday and today. Of course!

27 psi on initial key start, with it running, and with the fuel pump jumped as before, on my new Harbor Freight Master Fuel Injection Pressure Test Kit (which is a nice comprehensive setup for only $80 out the door with the 20% off coupon).

Recall when it would not start earlier this week I jumped the fuel pump and heard it running and cycling fuel through the system, same as it does today.

I'll adjust fuel pressure to the desired 30psi, but I'm even less convinced this is an issue with either the fuel pump or the mechanical pressure regulator.

Fortunately (unfortunately?) it's 18* outside and we're expecting up to two feet of snow Monday, so there's no pressing motivation to drive it...

More ideas appreciated.

- GA

Posted by: GregAmy Mar 11 2017, 11:41 AM

OK, here's some more data.

I was playing around with it just now, and of course without an AAR it idles like hell cold (future project). Started it a few times, fuel pressure is now at 30 steady, and then one time it died. And then it wouldn't start, same symptoms! Crank, brief fire, died.

So I break out the brake cleaner, open the TB and give it a squirt, then get in the car, starts up fine and I can keep it running with my foot, though it is running rough. Eventually it warms up enough to idle on its own. Starts and runs fine now.

Then I remembered something. A couple summers ago I had a hell of a hot start problem, where the car would not start when really hot, and I could smell fuel. If I kept my foot on the floor it would eventually fire and I could be on my merry way. And the car was getting shitty fuel economy, to the tune of 19-20 mpg.

Before you ask...fuel pump is in the front.

In reviewing the system - recall this car was a basket case when I got it - I found that there was no thermoswitch installed, the one that grounds the cold start valve. So, obviously, the CSV never worked and on the possibility that it was leaking I removed the hose and disconnected the plug.

I'm now thinking that this may be a/the problem, especially since it starts ok on brake fluid.

I searched through my Box O Parts and I can't find a thermoswitch. And it took about a half hour to find the wire for it as someone had just cut it off (it's another white wire buried inside the same pigtail as the harness for the distributor trigger points.) I still don't know if my CSV was the hot start problem, though I never had that problem again after removing it, could have been coincidence.

So I guess my next step is to obtain a thermoswitch and install it, and repair the wiring harness to it, and remove and test the CSV for wiring harness grounding and leaking.

Anyone have a thermoswitch and/or CSV laying around?

What is the correct control function of the CSV? I've read in one place that the valve only gets power from the ECU under cranking conditions, but I read in another place that if the thermoswitch fails closed the CSV is running all the time.

1:32 PM EDIT: We having fun yet? CSV does not leak under constant 30 PSI. CSV does not fire with key in the "on" position when wire for thermoswitch is grounded. CSV does fire when key is moved to the "start" position, then stops when released.

I need a thermoswitch.

Posted by: Dave_Darling Mar 11 2017, 07:19 PM

The CSV is powered by the yellow starter wire. It only gets power when the starter is cranking. The TTS grounds the other side of the CSV, and it provides the ground only when the engine is very cold.

Spraying starting fluid is something of a replacement for fuel. If the car runs on the starting fluid but not otherwise, you do not have enough fuel going in.

It's not your CSV.

--DD

Posted by: McLovin Mar 12 2017, 12:17 AM

Aren't the injectors electrical? Maybe you're not always getting electricity to them. Perhaps you've got a bad ground somewhere....like where the injectors are grounded. Do they screw in with electrically conductive (dialectric?) grease? I only dabbled with injectors once on another type of car so I don't know. But...As your engine warms up, you could gain even more resistance from the heat...perhaps enough to go over the tipping point to where the injectors don't work.

Can you re-ground the injectors?

Mclovin

Posted by: Dave_Darling Mar 12 2017, 11:10 AM

The only injectors I know of that are not electrical are MFI and CIS ones.

I don't believe there are any injectors that ground through the injector body. They all have a ground wire. Most injectors, in fact, have rubber holders that isolate them from the metal parts of the engine, so the body of the injector would be a lousy ground path anyway.

Most injectors are supplied a steady 12V (or less), and the ECU grounds the other pin of the injector to open it, and disconnects the ground to close the injector valve. D-jet is the main exception, as the injectors are always grounded and the ECU sends power to the other pin of the injector to open it and disconnects the power to close it.

The ground for the injectors is the same as the ground for the FI. It is a ring with three tabs on the case seam on top of the engine near the flywheel end. The ring goes under one of the case through-bolts. Always worth checking these grounds.


I will want to know what the fuel pressure is when the car does not start. Doesn't matter if it's 29 PSI when the engine is running, because the problem isn't occurring then.

--DD

Posted by: GregAmy Mar 12 2017, 11:24 AM

30 psi.

See post #32, specifically paragraph 2.

Posted by: McLovin Mar 12 2017, 11:36 AM

Interesting stuff. So he needs to check the ground and maybe the wires themselves for cracks or partial breaks.

Posted by: The Cabinetmaker Mar 12 2017, 12:14 PM

Sounds like Mctrolling to me.

Posted by: Dave_Darling Mar 13 2017, 03:36 PM

All you said was "fuel pressure is 30 psi", with no indication of when it was checked. I did not realize that you had checked it when the car was not starting.

If you did, that tends to rule out fuel pressure.



So, what we know right now:
- Starter cranks
- Starting fluid makes the engine start
- Fuel pressure is 30 PSI while the starter is cranking
- CSV is not hooked up


Since the starter cranks, we can rule it out.

Starting fluid takes the place of fuel, not of air or spark. So you have air and spark.

What you appear to be missing is fuel. But you have fuel pressure even when the car is not starting. BTW, if the pump is wired as per stock it is turned on and off by the FI's ECU, so if the pump runs then you do have power and at least some function of the ECU.

Next question: When the car does not start, do you have injector activity? A "noid" light from you FLAPS will tell you if the electrical signals are getting through. If you want to see the activity directly, you can stick one injector in an empty pickle jar while the starter is cranking and the car is in its no-start mode.

--DD

Posted by: Jeff Bowlsby Mar 13 2017, 03:45 PM

There is always Chris Foley around the corner from you before you give up.

Posted by: Mike D. Mar 13 2017, 04:02 PM

Fuel injector Trigger points in the distributor...?

Posted by: GregAmy Mar 13 2017, 04:25 PM

Hah! Nope, not giving up. I have a good relationship with those guys (Chris fabbed the race car for the prior owner and built the engine that's in it now) so I'll figger it out. Chip, chip, chipping away.


I've ordered the reman Cardone distributor from Advance. Counter Guy swears that if it's in the computer then he can get it (I'm doubtful) so we'll see.

I've temp-wired a switch in the engine compartment to ground the CSV for now and verified that the CSV shoots a nice pattern with key crank. We'll see if that makes any difference on cold starts.

In the market for a good used thermoswitch.

Posted by: Mike D. Mar 13 2017, 08:01 PM

Dist. trigger points don't fire the CSV/injector.
you can pull the distributor, remove/clean/check trigger points and re-instal on the stock dist. in the meantime. Or check for continuity while someone is cranking (disconnect coil while handling dist. in car)

Posted by: GregAmy Apr 6 2017, 09:10 AM

And the answer is...(or seems to be...)


Wait for it...


Bad MPS.

Haven't taken it for a drive yet (April showers and all that) but Tangetine rebuilt the MPS and it has totally transformed the car. Starts, runs and idles, doesn't suddenly die, idle is consistent.

Ed noticed a lot of my symptoms, plus some others I offered (such as I gave the ecu dialed full rich to stop surging at idle, and poor throttle response on the road) and figured I was running lean, and that the MPS needed rebuild. I found that diagnosis odd, given the MPS held a vacuum. So Chris suggested I try adjusting it instead. I removed it and handed it to them to mod for that, and they found a cracked diaphragm. They rebuilt it and when I bolted it on the car and started it up the difference was immediately evident.

Adjusted the MPS richer to move the ecu knob to the middle, adjusted ignition timing to 27, set idle and now it starts nicely. Plus, running lean and 10 degrees too much timing could also explain why it runs too hot in the summer.

As noted, I still need to take it out on a nice day, but I think we have this licked.

Scroll up and see if you called it like Ed did.

Posted by: Philip W. Apr 6 2017, 10:13 AM

I did!!!! Post #13 on first page! As I said then, had the same symptoms and frustrated the hell out of me. Almost sold the car-
Congratulations hope you can now enjoy driving it!! Maybe it will make it to Okteenrfest this year!!

Posted by: GregAmy Apr 28 2017, 06:54 AM

Just a quick follow up...the car is totally transformed. For those of you that have never experienced a bad MPS, trust me, this is like an automotive religious experience. Just spend the money because now my car that ran like total hell is a joy to drive: starts, idles, runs smooth, warms up nicely, and doesn't die when I push in the clutch at a light...with this system running correctly all thoughts of carbs is long, long gone.