924Board.org

[MikeDanger]

Arghhh, (man I start too many threads like that)

Well, I wasnt expecting to mess with this today, don't have the metal capacity for it right now

car ran fine last time (except for blowing off on vac line under boost!)

So Car isnt starting, So i richen it up a little (1/2 turn on the Fuel meter, and No; another 1/2 turn and again, No....Another 1/2turn and still No. Up to A full 3 turns and No.
I finally go it to kind of run with about 20sec continuous of cranking, by keeping the pedal floored and AT FIRST, it was kind of running with the starter, then it started to run on its own for a a few seconds but then when I let of the pedal it died.
Another try and same result, got like 1/2 a backfire.

(I also messed with my adjustable WUR (as I had messed a lot with it when my O2 sensor went bad and was trying to trouble shoot. My last drive, was the first since replacing the 02)

So i think, well maybe it was running with a WOT because it was too rich and that was the only way it would get enough Oxygen. So lets try leaning. Went back to "0" (where it was when it last ran) then starting going lean at 1/2 turns with not much difference except at some point it began to start then die. Figured it was the Cold Start injector, so i unplugged that, and that stopped the start/die issue.



So anyway, I thought well, that doesn't quite make sense, since if it wasn't getting enough fuel then going rich should have helped.

Lastly I swapped out my adjustable WUR for a stock one, again no improvement.

(also BTW fuel pump is new)
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It was either this or a giant box of legos

[MikeDanger]

just also to expalin my last drive. It was the first drive after installing the new O2 sensor. Car ran ok, needed some tuning, but no issues starting.

I went WOT and full boost, then blew off one of the 19mm hoses near the Throttle. Car lost power and I pulled over, then it died. I just put the hose back on, restarted and drove home.
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It was either this or a giant box of legos

[MikeDanger]

Here Might be one possible theory
So few years back driving my former, future Ex-wife's civic, it started to bog down when increasing the throttle. She had it towed to a shop, they called us down, and the mechanic showed me the open fuel tank and samples and said this smells weird, not like gas, said diesel maybe? But I doubt it was diesel... I surmised it must have been contaminated with E85, (Most likely Scenario)

Now a couple weeks ago in my Daily (2000 Bmw 540) I am having an issue with it, and I swap fuel pumps(don't let that throw you, 98% sure it not a fueling issue) and the tank is almost empty, but I put about 3 gallons in at a near by gas station. go for a drive, and after a while I notice a loss of power on the freeway, get a check engine light and while driving I plug in my code reader= Lean bank 1, Lean bank 2. Pull into a parking lot. Get a ride home to get some parts and tools. Check the Fuel pressure at the rail and its good and I notice the fuel smells a little funny. basically it smells weaker. not as pungent as gas usually does. so I eventually get it running and get to the nearest gas station and put some fuel in and its been ok ever since. Here again I figured it was funky gas.


So last night as I was swapping the WUR and got a whiff of the gas. I thought hey the station I got the gas in the 924 is a 1/4mi away from the place I got the gas in the 540, and they are the same Brand....
Now what I might be thinking is that YES the 924 is running lean, if it was being fed E85 (or some dilution of) and that the Cold start injector, was simply adding ENOUGH fuel to make it run. Rather that it was running on ONLY the Cold start injector? Basically to run on e85= fuel injector+ Cold start injector to provide a proper mixture to ignite.


but then I could be completely off.
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It was either this or a giant box of legos

[Mike9311]

I always go to the basics for something like this. I pull a plug and crank with someone watching the plug to see if there is spark. Of course sparking outside the engine is different than under compression in the engine but I need to verify. Then I use a starting fluid or flammable brake clean to see if it sputters or starts.

E85 is also a wicked cleaner. Run that too long and who knows what it released

If you are lazy (me too sometimes) just try a starting fluid. See if it farts
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1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car

[MikeDanger]

Im sure it has spark, as it starts, just briefly.

so the issue is I have opposite symptoms/results

I did try starting fluid and it did run for a second with that as well.

i can tell you this, I have a see through filter before the fuel pump, and while checking my Fuel sender I looked in the tank and it is MINTY clean! Looks like it just left the factory.
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It was either this or a giant box of legos

[Fasteddie313]

Finger the plate while cranking?
I love fingering the plate..
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80 Turbo - Slightly Modified

[MikeDanger]

[kondzi]

Haha we might have same gremlin. I just had issues with my 931 starting after winter. Spark plugs are flooded in my case though. Need to go through the CIS pressure test procedure again it seems for me.
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Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded)

[MikeDanger]

[kondzi]

Well it was sitting, but I was moving it around a bit every few weeks or so in my garage/parking area. Kind of a Tetris game honestly. Anyway one day it wont start - cranking and cranking and finally fired up, but not on all cylinders. Need to check wiring first, as this might be as easy as losing spark due to some old wiring harness corroded over the cold winter days. Check your spark plugs. It’s easy to flood k-Jet / CIS.
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Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded)

[joemoma1990]

I have the same problem. I did have mine running although very rough, I tested the WUR and it was not working so I replaced it and now it will only fire but not stay running. Now that it is getting warm here I am going to go through the injectors again I think

[MikeDanger]

well, the pump is good, I tested the system pressure and was getting 80+ (wasn't able to test control pressure as the valve would leak when open, im going to get another valve tomorrow)
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It was either this or a giant box of legos

[MikeDanger]

Damn, well I still dont know, got a ethanol tester, and the Gas is only 5% ethanol, so thats not it.

I got a new valve to check control pressure right now its just over 20psi Cold. I dont know how much the mixture screw affects it, but its not to far out of range according to the factory manual.

Now the System pressure was 95 with the valve closed. thats a little high, but Not sure that it matters?

What could have "blown" on a full boost run? (but the car was still running after that?)

What if the aux air regulator was stuck closed? or the decel valve failed?
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It was either this or a giant box of legos

[MikeDanger]

if it was the digital ignition/flywheel sensor, would it even fire?
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It was either this or a giant box of legos

[Fasteddie313]

Have someone else crank and you finger the plate..
Or run a gator clip wire or jumper cable from the starter Solinoid and touch it to the big hot on the alternator while your under the hood..

Watch the plate while cranking and it should be bouncing..

Kinda sounds to me like you might have ripped your boot between the turbo and the bottom of the air metering housing but that’s just a WAG..
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80 Turbo - Slightly Modified