Engine shuts off

[curterj145xr]

I have been trying to fix this for a while now. You can be sitting at a stoplight and the engine either just quits or starts running rough and gags when you give it any gas. If I try to re-start it, it won't start. But if I go to full key off, then re-start it, it starts up and runs fine.

Fuel pump, crank sensor, and rear 4 coils have been changed and I'm running out of ideas.

 

[SHOZ123]

IAC? I run my throttle plate just a hair open. This gives the IAC more headroom.

 

[Lesgo5oh]

I have been trying to fix this for a while now. You can be sitting at a stoplight and the engine either just quits or starts running rough and gags when you give it any gas. If I try to re-start it, it won't start. But if I go to full key off, then re-start it, it starts up and runs fine.

Fuel pump, crank sensor, and rear 4 coils have been changed and I'm running out of ideas.

I recently purchased a 97' SHO w/ Cam Failure and just finished the motor swap - i'm having this EXACT same problem and I'm running out of ideas as well. Everything functions properly, no check engine light...the car will run great all day, then it will die on me. I'll have to shut the ignition off and re-start. Have you figured out what is wrong yet? My next step is the fuel pump relay. Good luck....

 

[Lesgo5oh]

Update: Took my car to a "computerized car care center" and they told me one of my coil packs (which particular one unknown) is shorting back into the computer, shutting the computer off. Does this sound right? I had a few extra coil packs so I went through all of them, front and rear, and the problem still persists.

One thing I'd like to note is that I can keep the car running w/ my foot on the gas, but it does not want to run. Black smoke bellows out the exhaust. As soon as I let off the accelerator, it dies. Shut the ignition off, turn it back on and it's fine (until the problem repeats itself). Please help!

 

[SHOZ123]

Yes that is possible and in fact is a known problem. It can also cause problems with the MAF. Used coils are a gamble as you can't really tell a good one from a bad. Just dead or almost dead ones.

 

[naval-avi8or]

I have a similar problem occasionally my car will die under braking to a stop. Happens sometime for several days in a row and then won't do it again for several months. It seems to do it at about the same distance (6-8 miles)/driving time (10 min) after the first start of the day. Car will re fire and not have anymore problems for that day.

 

[Lesgo5oh]

Is there any way possible that this could be caused by the engine being a year newer than the Vehicle & ECU? There was a difference between the injectors and injector rails which I switched over, but all of the sensors on the replacement engine were used. The original MAF was used.

 

[ThatShoGuy]

Is there any way possible that this could be caused by the engine being a year newer than the Vehicle & ECU? There was a difference between the injectors and injector rails which I switched over, but all of the sensors on the replacement engine were used. The original MAF was used.

try changin out you # 8 coil it will put radio wave (beleaves thats right) into the mafs cirucute and make it go crazy and may your car not run right...

kind of like this, this is my sho at one point

http://youtube.com/watch?v=DMD2UZEvGH0

http://youtube.com/watch?v=qw4szZXDVuw&feature=related

good luck took me 3years to figure mine out.. hope it take you as long..

happent to be that #8 coil..

 

[SHOZ123]

Screw the throttle stop in until it makes contact with the throttle stop arm when the engine is off. Then turn in a quarter turn. Disconnect the battery and let the car relearn idle.

OR

Screw the stop in with the car hot and idling until the engine is idling about 1500 rpm. Then disconnect the IAC. Then back the throttle stop screw out until the car idles at about 400 rpm. Shut the car off, reconnect the IAC and disconnect the battery. Start car back up to relearn idle.

 

[Lesgo5oh]

try changin out you # 8 coil it will put radio wave (beleaves thats right) into the mafs cirucute and make it go crazy and may your car not run right...

kind of like this, this is my sho at one point

http://youtube.com/watch?v=DMD2UZEvGH0

http://youtube.com/watch?v=qw4szZXDVuw&feature=related

good luck took me 3years to figure mine out.. hope it take you as long..

happent to be that #8 coil..

ThatShoGuy - Your videos pretty much duplicate the problem I'm having. When you left off the gas will the car die? Did you by any chance notice black smoke coming out the tailpipe when you were experiencing these problems?

Thanks for the help...........
Todd

 

[Exitwound]

Have you guys don what Paul has suggested. It is a simple free suggestion that works, I have done it. If you have not done it yet go do it and see if the problem persists.

 

[Lesgo5oh]

Have you guys don what Paul has suggested. It is a simple free suggestion that works, I have done it. If you have not done it yet go do it and see if the problem persists.

I have not done what paul has suggested. I may give this a shot tonight, but I don't see how the problems I'm having could have anything to do with the idle speed. I'll give it a shot and post back tomorrow.

Thanks to all...

 

[ThatShoGuy]

ThatShoGuy - Your videos pretty much duplicate the problem I'm having. When you left off the gas will the car die? Did you by any chance notice black smoke coming out the tailpipe when you were experiencing these problems?

Thanks for the help...........
Todd

i dont remenber if there was black smoke if i could i would say yes but im unsure...

also some times i couldnt keep the car running some times i could.. all denpened but one thing was sure.. its started to happen every once in a while then it got worse and worse to the point were you couldnt drive the car...

 

[Lesgo5oh]

I have not done what paul has suggested. I may give this a shot tonight, but I don't see how the problems I'm having could have anything to do with the idle speed. I'll give it a shot and post back tomorrow.

Thanks to all...

I tried the IAC trick and thought it had fixed the problem, but once the car was warmed up it stalled on me again.

I haven't messed with the #8 coil plug as I've already rotated through all of the coil packs I have. With every combination of coil packs I'm still having issues. Could this be related to a bad MAF sensor?

 

[ThatShoGuy]

I tried the IAC trick and thought it had fixed the problem, but once the car was warmed up it stalled on me again.

I haven't messed with the #8 coil plug as I've already rotated through all of the coil packs I have. With every combination of coil packs I'm still having issues. Could this be related to a bad MAF sensor?

have you tryed to clean the maf sensor?

if not i would give that a shot.. never know.. i need to clean mine.. but just been to lazy..