Stalling; won't start (flooding)

[Spectator DragR]

Yesterday my Sy had some trouble running shortly after starting. It started fine, then while it was idling down it just quit. I smelled gas. Had to floor the gas pedal to get it started again- lots of smoke out the exhaust! Ran fine on my 2 mile drive home from work. Now it's doing the same thing again today. Spark plugs (only checked #1) are wet- big time! Have to let it set a while before the WOT starting procedure works again... then it will quit again... need help. No codes on diacom after it quit.

 

[Mkid]

Stock truck?? heres the test procedure to check if the injectors are leaking at prime>>



1. run the pump. clamp the fuel feed line at the firewall{drivers side}. turn pump off. If pressure now holds, it is the check valve in the pump that is allowing bleed-off.

2. run pump using 'prime' connector. clamp retun line to pinch it closed at the rubber section at bottom of firewall. Turn pump off. If pressure now holds, it's the regulator allowing pressure bleed-off.

If the pressure fails to hold in either test, the injectors are leaking.

hope this helps.

 

[ItsMyTy]

check your fuel pressure regulator vaccum hose for fuel

it's possible you have an injector sticking open or a wiring harness grounding out one of the injector ground wires causing them to stay "on"

 

[Spectator DragR]

The truck has been sitting since Sat morning. Today (Monday)- I checked for pressure at the fuel rail- gas came spewing out. Linked via diacom, started it up (didn't touch gas pedal during all this). Everything was normal until stall... idled up to 1575, then slowly came down to 750. Start-up temp was 21 F this morning! Coolant temp was at 81 F when it stalled. O2 read 450 at start-up, increased to 800ish (O2 NEVER went down from start-up to stalling). Integrator was 128 at start-up, then slowly dropped to 80 once LOOP_STAT switched from OFF to ON. Integrator stayed at 80 until it stalled.

Pulled vacuum hose off regulator- no fuel there... but did manage to break the plastic T at the rear of the upper manifold. Going to fix that now.

It has an aftermarket fpr- been on there since I've had the truck (8 years). Stock ECM/chip too.

Do I all of a sudden have TOO MUCH fuel pressure??? Going to borrow a gage to check pressure at fuel rail today...

Did I mention this is my daily driver???

 

[Spectator DragR]

The fuel pressure gage I borrowed leaked! While under the hood cleaning up the fuel on the engine, I heard the injectors ticking. I never cranked the engine once I installed the pressure gage. I left the key on while under the hood tending to the fuel leaking issue.

The injectors should NOT make any noise with the engine NOT running... RIGHT???

I've also got quite a bit of black "sludge" coming out of the exhaust. I'm guessing that's fuel and oil... Man, that 2005 Pontiac GTO is looking good right now.

 

[ItsMyTy]

you shouldnt have any injectors clicking with the engine not running.

i had a similar problem with my truck. still dont know where the problem is, but i figure it's the injector ground wire shorting to ground somewhere in the harness. mine was flooding the engine out to where it wouldnt even start, just by turning the key on. i grabbed the harness and moved it around and the problem hasn't been back since.

 

[Spectator DragR]

I will be trying a different ECM (out of a 93 Ty) tomorrow. IF that doesn't work, how should I go about finding a possible grounded injector ground???

Oh, should I put my chip (AYBM 4053) in the Ty ECM or just run the Ty chip?

Thanks

 

[Jimmy]

Is there gas in the oil?

 

[Spectator DragR]

Yep- gas in the oil. I've started it 4 times since this problem has started. Major black sludge coming out the exhaust and the engine compartment smells of gas and the oil smells of gas (on the dipstick).

 

[SY2455]

You don't want to start it too much with gas in oil, Motor No Like & you won't like the repair cost. I learned from Experience.

 

[Jimmy]

I say it's the fuel pressure regulator.I had one with a broken diaphram hydrolock (temporarily) the engine in my old black Ty.

 

[Spectator DragR]

now running

now running

Put in an ECM from a 93 junkyard Typhoon Friday. Started right up. At first I thought it was gonna stall because the O2 stayed high, the integrator went down to 80... then it went from Closed Loop ON to OFF. Gave an O2 rich code, then the integrator went to 128 and stayed there (it kept running, never tried to stall). I let it run a while longer and the O2 sensor finally started bouncing around. Must have burned off some junk that coated it from all that flooding before.

I was hoping the new (different) ECM would some how get rid of my knock retard... but it didn't. The only way I know how to do that is to unplug the knock sensor- but I know better. I've ony heard knock one time when my spouse put 87 octane in it. Oh well.

Oh, the fuel pressure was at 53. Now I've got it at 44.

Does anyone have a COLD START diacom file I could view? Thanks.