Weird stalling problem
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Safety Car
Joined: Dec 2004
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From: Poop land
Weird stalling problem
I was driving back to work and suddenly the car stalls out. I put it in neutral and restarted it while neutral coasting. Idled roughly. Pushing the gas pedal stalled it again. Coasted to the side and checked to see if any codes were set. No codes! Tried to start it again. Starts right up, but with the idle really low and rough at 400 rpms. Yep, pushing the gas will stall it. So I get a quick idea and disconnect the battery cable while doing a quick visual inspection. Didn't find anything else. After disconnecting the battery and reconnecting it, she starts up fine and I'm down the road again. Any ideas?
Thread Starter
Safety Car
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From: Poop land
Forgot to add, sometimes there would be a very delayed response from the throttle and on cruise the rpms would drop to about 600-800 like I'm in neutral. Then, when the throttle is pressed again, it would either return to normal or it would stall out. Problem is very intermittent and happens when you least expect it, e.g. coming back to and from work. 
:
Edit: And like I said, NO codes were set!!!
:Edit: And like I said, NO codes were set!!!
Last edited by kopbet89c4; Apr 5, 2006 at 08:57 PM.
Thread Starter
Safety Car
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From: Poop land
Fuel pressure is 44 psi. Filter was changed 4 months ago on a scheduled maintenance. Hose for FPR to the intake is fine and has no leaks.
Took it for a scan. TPS shows normal reading and is not jumpy.
Took it for a scan. TPS shows normal reading and is not jumpy.
Last edited by kopbet89c4; Apr 5, 2006 at 09:18 PM.
Intermediate
Joined: May 2003
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From: TX
My 93 vette did the same thing to me just last week. I did change the fuel filter and glad I did as I was unable to blow through the old one. The next day it ran fine then later that night it would start for 2 seconds and then shut down showing signs of no fuel. Fuel pressure was fine. the next two days have been perfect with no hard starts or engine stalls during driving. I checked Coil, ign control FP FPR. Just waiting for it to happen at least long enough to give me a code.
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Safety Car
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From: Poop land
Unless the TPS was sticking intermittently, will cause a stalling problem without a code?
BTW, the O2 sensor connector locking clip is broken and maybe the connection to it was loose. Could this cause a stalling problem if in closed loop mode?
BTW, the O2 sensor connector locking clip is broken and maybe the connection to it was loose. Could this cause a stalling problem if in closed loop mode?
Le Mans Master
Joined: Feb 2005
Posts: 5,146
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From: The Motor City
Originally Posted by kopbet89c4
the O2 sensor connector locking clip is broken and maybe the connection to it was loose. Could this cause a stalling problem if in closed loop mode?
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Thread Starter
Safety Car
Joined: Dec 2004
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From: Poop land
Now right after the start up with the idle at 400 rpms, what would cause the car stall when I even *slightly* push the throttle?
Why are there no codes set, even if the car idles low and roughly like that for awhile???
Why are there no codes set, even if the car idles low and roughly like that for awhile???
Last edited by kopbet89c4; Apr 5, 2006 at 11:12 PM.
Thread Starter
Safety Car
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From: Poop land
This problem has the same symptoms as my MAF problem last year. Pushing the gas pedal would stall the engine. I'd disconnect the MAF and the car would run good enough to drive to the parts store to get a new one.
I dunno if there would be vacuum leaks because the car will run fine for at least 3 days after the battery is disconnected for 1 minute and then reconnected. This is like having to recheck this problem in 3 days right when the car stalls in the middle of the road. Unless a TPS could go bad intermittently without setting a code...
Sometimes I wish the car would have this intermittent problem on my driveway or garage so I can diagnose it ASAP, instead of the problem "temporarily" fixing itself while on the road.
Symptoms are described exactly to my knowledge in post #2
I dunno if there would be vacuum leaks because the car will run fine for at least 3 days after the battery is disconnected for 1 minute and then reconnected. This is like having to recheck this problem in 3 days right when the car stalls in the middle of the road. Unless a TPS could go bad intermittently without setting a code...
Sometimes I wish the car would have this intermittent problem on my driveway or garage so I can diagnose it ASAP, instead of the problem "temporarily" fixing itself while on the road.
Symptoms are described exactly to my knowledge in post #2
Last edited by kopbet89c4; Apr 5, 2006 at 11:35 PM.
Le Mans Master
Joined: Oct 2003
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From: seattle WA
Hmmmmm, have you ohmed the pickup coil?? make sure you wiggle the wires when you do-that is a major part of testing it-I would also take the ignition module into Atuzone for testing-have them run it through 10 cycles-or the test is meaningless.
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Safety Car
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From: Poop land
Well, fuel pump is less that 1 year old. I was able to start it 12 times in a row and drive with all throttle variations. Ran like a champ, and as healthy as a horse. Not a stumble, or any problem whatsoever.
Rick, I'm sure the ignition coil and all of its components are working well since they were replaced last year at around this time. According to the recent scan, like an hour ago, the timing is advancing like it should. The TPS signal is also right where it should be (.54 volts) and is steady with more throttle going up to 4.6 volts on WOT.
Rick, I'm sure the ignition coil and all of its components are working well since they were replaced last year at around this time. According to the recent scan, like an hour ago, the timing is advancing like it should. The TPS signal is also right where it should be (.54 volts) and is steady with more throttle going up to 4.6 volts on WOT.
Thread Starter
Safety Car
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From: Poop land
Test drove the car again and yep, it indeed stalled once more. Restarted it and the gas pedal acted exactly like the stall engine switch while still coasting down the road. I restarted the car while coasting just before the entrance to my neighborhood and the idle becomes super rough and low at 400 rpms again. The car was still coasting closer to the subdivision and I tapped the throttle, the rpms went up to about 3500 and suddenly the drivability returned, without me having to disconnect/reconnect the battery. Returned home and parked in the garage. Shut car off, restarted car again, and it starts normally. Hmmm... what's going on with this God forsaken thing????????
Melting Slicks
Joined: Jan 2002
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From: Milan
While datalogging see the steps of the IAC.
During VERY low idle (about 450 or so..) it's typical having a stall applying gas.
A 450 rpm idle it's a IAC problem.
Disconnecting the IAC in a stock car the Idle goes at a minimul level possible (around 400-450 rpm)
If the commanded idle it's 700 in Park or 600 in D ... the difference from 450 is all in IAC stps applyed by the computer.
-Beppe-
During VERY low idle (about 450 or so..) it's typical having a stall applying gas.
A 450 rpm idle it's a IAC problem.
Disconnecting the IAC in a stock car the Idle goes at a minimul level possible (around 400-450 rpm)
If the commanded idle it's 700 in Park or 600 in D ... the difference from 450 is all in IAC stps applyed by the computer.
-Beppe-
Thread Starter
Safety Car
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From: Poop land
Each time the car is connected to the computer, I have to put a 10k resistor between A and B to put it in diagnostic mode. I drove around with the car connected to the scanner for 45 minutes straight and not once did it have a problem stalling out.
Is it possible that when the computer is connected to the ALDL port, it has a very different air/fuel curve?
Is there something that the car is doing causing the computer to either cut out fuel or dump too much fuel during this intermittent problem?
I feel like the car ran a lot better with that 10k resistor...
Is it possible that when the computer is connected to the ALDL port, it has a very different air/fuel curve?
Is there something that the car is doing causing the computer to either cut out fuel or dump too much fuel during this intermittent problem?
I feel like the car ran a lot better with that 10k resistor...