engine stalls at stops

[kracer1]

My 97 SHO has started to stall when slowing to a stop at stops and traffice lights. After turning the ignition off and then back on the car usually starts back up. I've replace the IAC and the TPS to no avail. Any suggestions on what else to look for would be appreciated.
gk

 

[UnseenSHO]

I was having the same problem with my SHO was randomly stalling when going at slow speeds stop signs. etc. but stable when moving although it would stall when moving on ocasion.We cleaned the Throttle Body with some cleaner and it ran like new.

Not saying this is the same solution for you,but it's something you should check out!


This was happening with my '93 MTX

 

[kracer1]

I'm going to give that another try. My daughter was driving the sho at school and since she's graduated and has a real job now she bought herself a car so I get the old one back and have to figure out what's wrong with it. At least I'm not diagnosing problems long distance. I had her boyfriend "supposedly" clean the MAF but I'm going to do it again for my own sanity. thanks,
gk

 

[SHOZ123]

I would open the throttle plate a 1/4 turn after making contact using the throttle stop screw. Then disconnect the battery to clear out the learned idle memory.

 

[kracer1]

haven't thought of that, i'll give it a try. thanks,
gk

 

[NebraskaSHO]

Paul, I haven't cracked the throttle screw but the car has only stopped twice since our emails. If it dies again I will mess with it as you suggested.

I also got 22 mpg in the car, 19 normally, and the car was locking the tcc much more than normal. I was so excited driving yesterday!

 

[kracer1]

Well I cleaned the MAF yesterday and when returning to work from lunch the car died at a stop light. First time I"ve experienced it since I brought the car back from Orlando. It started right up after putting it in park, turning the ignition off and then restarting so tonight I made a change to the idle adjustment screw. I'll see if this makes any difference.

 

[SHOZ123]

Good to hear Paul. I have another tune here that may get another mpg or so.

 

[JCTaz]

My 97 was doing the same thing and it turned out to be a bad coil pack... dealer said it was the #3 coil pack, so I replace all 8 and have had no problems since.....

 

[kracer1]

Arrgh! made the throttle body adjustment, reset the computer and it died again yesterday at a traffic light. My check engine light stays on all the time since that d@#$ air injection pump code tripped but every time one of the coils failed i've gotten a trouble code for that cylinder. I'm going to see if i can get the air pump fixed and go from their.

 

[PFA]

Any update on this???

I am having a very simular problem right now. I am leaning towards the MAF.
Looking to find what other cars cross with the 97 SHO.

 

[Mr Anonymous]

Stalling issues can usually be traced to the most common V8 SHO maintenance problem -- one or more dying/dead coil packs.

If the MAF and IAC have been eliminated as potential causes, the coils would certainly be the next place I would start looking. Start with the coil on cylinder 8 and swap it with the coil on cylinder 5. A leaky coil at #8 can cause RFI that skews the MAF signal to the PCM.

 

[SHOZ123]

Did you open the throttle stop a small bit?

 

[PFA]

I have tried that, but when it wants to die, it does. It is intermittent. I cannot even trust it for a 7 miles run to work. It usually does it when it's warmed up.


I had this on the V8 list too. Just looking for some more input..


Thanks

 

[SHOZ123]

There was a issue with the a coil(s) misfiring and that backfeeding into the PCM MAF ciruits.

 

[PFA]

I am going to swap out #8 with another one.
Unfortunitely, I have not thrown a code on this since resetting a P1121. That is the MAF and TPS not reading the same thing.....
I replaced the TPS and the Maf was cleaned. No change.

Thanks

 

[naval-avi8or]

Well I cleaned the MAF yesterday and when returning to work from lunch the car died at a stop light. First time I"ve experienced it since I brought the car back from Orlando. It started right up after putting it in park, turning the ignition off and then restarting so tonight I made a change to the idle adjustment screw. I'll see if this makes any difference.

My car does the same thing. You mentioned that you put it in park and turn the ignition off/on. Have you ever tried to shift to Nuetral and strat to start. That works for me.

If you figure out what's causing it please post the solution.

 

[SHOZ123]

Are the coils you are swapping out know good ones?

have you checked the wiring for the coils on the back bank?

 

[PFA]

Ok...I swapped the #6 and #8. Kind of a stupid move....
I know have a broken cable on the secondaries. BUT....
I have driven it about 20 miles now. No stalling. I swapped out the #6 coil with a spare that I have.....No, not known good or bad. It felt better but still feels like there is a misfire somewhere. Only code being thrown is for the secondaries. I hope this at least solved the stalling problem.

Now then, I'm off to research the broken cable. I hope it can be replaced without getting a whole new unit.

Thanks for the help!!!

 

[kracer1]

Adjusting the TB didn't help me any. It stalled again but I've since torn apart the front end and so it hasn't moved in several plus weeks. I'm going to replace the last I believe coil and see if that does the trick. If not I'm still lost. I'll post up later