engine dies while driving, starting problem

[Mike Coons]

My 1991 SHO, with nearly no modifications, has the following symptoms. Occasionally, the engine shuts off while I'm driving (3 times now). Also, when starting, the cranking process sometimes hesitates a second or so, continues cranking briefly, hesitates again at which time I stop trying to start it. Thus far, everytime this has happened, I have been able to get it running one of the next three attempts. These two symptoms started around the same time. I don't know if this is an electrical issue (maybe alternator) or possibly a problem with the carberator or misfiring of some plugs. All advise is welcomed, Thanks.

 

[jthomas68]

It`s most likely the CPS(crank position sensor).Next time it happens,look at the tach.If it reads 0 while cranking,that`s the culprit.

 

[jcostantino]

Could very well be early stages of a crank sensor failure.

The problem you have starting where it hesitates as it turns over sounds like my problem, which was a leaking head gasket. That cost the warranty company about $2000 so hope that it's just a weak battery or starter.

Have them tested at Autozone for free just in case.

Jeff

 

[naval-avi8or]

on't rule out fuel pump failure. If its cps it will store a code in the computer. If its fuel pump it more than likely will not.

 

[jthomas68]

The CPS does not throw a code.Rarely,it throws a code in relation to the problem,but the CPS itself with not trigger a CE light.

 

[Mike Coons]

Thanks for the replys. I'm almost positive that the tack was at 0 the last time it happened. Would the CPS failing account for both of my symptoms or just my starting issue? Thanks again.

 

[jcostantino]

The crank sensor (PIP or CKP, not CPS - that's cam sensor) usually causes your car to stall and sometimes lets it fire right back up. When it really starts to fail, it starts to take longer and longer until your car can start up. You'll still be able to crank the car but you won't get spark until the CKP cools down again.

My crank sensor started to fail as a stall with immeadiate restart when I stopped at a light.. it gradually because a 5 minute delay in starting then 10, then 15, and I replaced it.

Jeff

 

[sdpatt]

The CPS failure does set a code. That is why there is a code 14 and 211 for the different versions of the EEC. There are, apparently, some modes of failure that do not set a code. But I have not yet personally seen that case.

The CPS failure will not have an effect on the cranking speed. The engine will either start or it won't start. The cranking speed can be affected by the battery health, starter health, continuity of the battery connections and cabling to the starter and the cylinder identification sensor (CID, aka the camshaft position sensor) sensor. The CID failure can cause a backfiring and rough startup as the EEC is trying to figure out which cylinder is which by trial and error.

 

[jthomas68]

Mine never tripped the CE light,or set a code.It just started to die one day.

 

[SHOMA]

my 94 atx had the same problem, except when it died, it DIED! for a good 5-20 mins, then would start and run like no tomorrow... No CE light, but it did bring up a code, thats how i determined what it was... GOOD LUCK!