It wants to die

Rebel79 · 12-31-2001, 10:59 AM

I really don't know how to explain this. This problem has been occuring since the end of June. It started out happening on occasion, to the point now where it happens everytime I drive it.

First off, it will want to die at idle. This can happen 5 times at one light or not at all on a given day. When it does want to die, the rpms drop as low as 200 and even though I give it gas, it just stumbles, and sometimes it takes 5 seconds or so to get it idling again. I can only describe it as a 'miss'.

Now this same type of 'miss' occurs on acceleration sometimes all the way up to about 3k. The car will also bog as high has 2,400rpms and have NO POWER until about 4k. If I let off the throttle and reapply then it again 'stumbles' and does not go anywhere.

This problem is REALLY annoying and I need to fix it ASAP.

EDIT** oh yeah the car also will backfire. This has only happened a few times, it usually happens when letting off the throttle, usually in 4th gear. If I rev it up in neutral (just to prove that it does backfire) and let off around 5k, 1 foot flames shoot out of each tailpipe. It sounds like an M-1000 went off in the back of my car. I know its not good. So obviously its running rich on de-accel but something else is making it backfire... anyone?

exgmguy · 12-31-2001, 11:26 AM

Bad oxygen sensor(s)???

Phantom5oh · 12-31-2001, 12:07 PM

What years is the car? What mods have you done to it recently? To me the backfiring makes it sould likes its going lean. The stalling and no power until your RPMs are up sound like it could be any number of things. Do you get a check engine light while this is happening? If not then I doubt its O2 sensors. Is it hard to start back up when it dies? I would check the Idle Air Bypass Valve (or Idle Air Control Valve) for a good starting point. I just replaced one in my brother car for a similar problem. Part was cheap and solved the idling issue, backfiring, and no power problems he had too.

Steve

Rebel79 · 12-31-2001, 02:02 PM

Oxygen sensors are new. I do have a spare IAB lying around so I'll try that, but the one I have on there is good as far as I know and it has been recently cleaned.

Phantom5oh
Read sig for year.

Most recent mod would be MSD 6AL and BTM and JMS chip but this was almost a year ago. The MSD 6AL and BTM were recently moved into the engine compartment, but this was AFTER the problem started to occur.

Now here is where it gets interesting. I can reset the EEC and have the car run awesome! Sometimes the car will run great for 3-4 days before the problem occurs... other times it can take the EEC 15 minutes to readapt and cause problems again. I even removed the JMS chip and removed the MSD 6AL and BTM and no change.

Any other ideas?

Rebel79 · 12-31-2001, 02:05 PM

Oh and Phantom, the car never actually dies, it will actually idle long enough at 200 rpms for me to be able to apply throttle. I can give it half throttle sometimes and it won't even do a thing...

Phantom5oh · 01-01-2002, 02:56 PM

hmmm that is interesting... sorry i totaly missed the year in the signature... my bad... but yeah no that doesn't sound like the IAB then... i'm not sure i will hafta think about it... its always tough to diagnose a car without seeing it... how is your fuel pressure?

Steve

12-31-2001, 10:59 AM	#1
Rebel79 News Editor Join Date: Apr 1999 Location: Concord, CA Posts: 2,101	It wants to die I really don't know how to explain this. This problem has been occuring since the end of June. It started out happening on occasion, to the point now where it happens everytime I drive it. First off, it will want to die at idle. This can happen 5 times at one light or not at all on a given day. When it does want to die, the rpms drop as low as 200 and even though I give it gas, it just stumbles, and sometimes it takes 5 seconds or so to get it idling again. I can only describe it as a 'miss'. Now this same type of 'miss' occurs on acceleration sometimes all the way up to about 3k. The car will also bog as high has 2,400rpms and have NO POWER until about 4k. If I let off the throttle and reapply then it again 'stumbles' and does not go anywhere. This problem is REALLY annoying and I need to fix it ASAP. EDIT oh yeah the car also will backfire. This has only happened a few times, it usually happens when letting off the throttle, usually in 4th gear. If I rev it up in neutral (just to prove that it does backfire) and let off around 5k, 1 foot flames shoot out of each tailpipe. It sounds like an M-1000 went off in the back of my car. I know its not good. So obviously its running rich on de-accel but something else is making it backfire... anyone? __________________ Scott Halihan, News Editor** The MustangWorks Magazine 1994 Supercharged Mustang Cobra Rebel Racing. Home of Bay Area Mustangs

12-31-2001, 11:26 AM	#2
exgmguy Registered Member Join Date: Feb 1999 Location: Utica, Michigan Posts: 2,631	Bad oxygen sensor(s)??? __________________ 1988 Mustang GT stock bottom 302, C4 10.9 @ 128 with 8 psi of Novi 1000 boost!----STOLEN 1989 Mustang notchback Warmed up 306 with a Procharger.

12-31-2001, 12:07 PM	#3
Phantom5oh Registered Member Join Date: Mar 2000 Location: Boston, MA Posts: 334	What years is the car? What mods have you done to it recently? To me the backfiring makes it sould likes its going lean. The stalling and no power until your RPMs are up sound like it could be any number of things. Do you get a check engine light while this is happening? If not then I doubt its O2 sensors. Is it hard to start back up when it dies? I would check the Idle Air Bypass Valve (or Idle Air Control Valve) for a good starting point. I just replaced one in my brother car for a similar problem. Part was cheap and solved the idling issue, backfiring, and no power problems he had too. Steve __________________ 95 GTS 03 DR 650SE Sgarzi's Machine Works

12-31-2001, 02:02 PM	#4
Rebel79 News Editor Join Date: Apr 1999 Location: Concord, CA Posts: 2,101	Oxygen sensors are new. I do have a spare IAB lying around so I'll try that, but the one I have on there is good as far as I know and it has been recently cleaned. Phantom5oh Read sig for year. Most recent mod would be MSD 6AL and BTM and JMS chip but this was almost a year ago. The MSD 6AL and BTM were recently moved into the engine compartment, but this was AFTER the problem started to occur. Now here is where it gets interesting. I can reset the EEC and have the car run awesome! Sometimes the car will run great for 3-4 days before the problem occurs... other times it can take the EEC 15 minutes to readapt and cause problems again. I even removed the JMS chip and removed the MSD 6AL and BTM and no change. Any other ideas? __________________ Scott Halihan, News Editor The MustangWorks Magazine 1994 Supercharged Mustang Cobra Rebel Racing. Home of Bay Area Mustangs

12-31-2001, 02:05 PM	#5
Rebel79 News Editor Join Date: Apr 1999 Location: Concord, CA Posts: 2,101	Oh and Phantom, the car never actually dies, it will actually idle long enough at 200 rpms for me to be able to apply throttle. I can give it half throttle sometimes and it won't even do a thing... __________________ Scott Halihan, News Editor The MustangWorks Magazine 1994 Supercharged Mustang Cobra Rebel Racing. Home of Bay Area Mustangs

01-01-2002, 02:56 PM	#6
Phantom5oh Registered Member Join Date: Mar 2000 Location: Boston, MA Posts: 334	hmmm that is interesting... sorry i totaly missed the year in the signature... my bad... but yeah no that doesn't sound like the IAB then... i'm not sure i will hafta think about it... its always tough to diagnose a car without seeing it... how is your fuel pressure? Steve __________________ 95 GTS 03 DR 650SE Sgarzi's Machine Works