Anyone have any idea's?

[john51md]

91 Lumina 2.5 auto
Stopped at a store about 15 minutes, car shut off. Tried to start it, it just cranked. Tried this about 10 times over 20 minutes, then it instantly started up, seemed fine.

Started home, made it about 10 miles, car dies cleanly on the road. Checked at spark plug, wasnt any fire to any plug. Was almost home so i had brother tow it rest of the way. Car was "off" about 1/2 hour. When we got it into driveway, i hit the key and it started right up.

I put in in my garage, ran it in park about 15 minutes at a higher idle, instantly died, would not restart, it sat for about 15 minutes with hood up, it restarted again. (oh, checked this time as well for fire at plugs, was none)
So... I put a new Ign. modual on it, started right up. Ran it around about a half hour, seemed ok. Loaded wife and 3 yr old granddaughter up, started to town (same store it originally stopped at) ran fine till i got about the same distance from the store, as i did from store to home trip previous night when it quit. Yes it quit again, cut off cleanly in middle of road. Just cranked, no fire at all to plugs.
Had it towed about 2 miles to my sons house, unhooked it, and it started right up. Let it sit there and run about a hour and it didnt shut off. Was afraid to go back out on the road with it, so i left it overnight, trying to decide the cause.

I thought well... this car isnt that techno.. so what is left that can kill it this way? ECM? SO next day i bought a new ECM and put in it, started, ran for over a half hour around his driveway (back and forth) seemed ok, so started home, this time it didnt shut off, it made it home, but has no power, pops up thru intake now and then when you try to accelerate, when slowing trys to miss some, so now its at home, afraid to go back on road with it.
I still cant rule out that it wouldnt shut off and not start again though.

ANyone have any idea's i havent thought of? oh, and plugs, wires, coils are new, all sensors have been replaced over last year or so, charges fine too. I just dont know what else it can be, oh, 2 months ago i also put a new fuel pump, filter, and gas tank on it.

The only code set is has is the same code it has had for the last 4 years, a EGR code, and that is because the EGR doesnt work,(hose plugged) on this the EGR is the simple one hose, no electric wire type like on old GM V8 engines.
Just seems heat related because of stopping almost the same distance i drive it each time. But other than ECM, and Ign. modual, what the heck else could cause a heat issue i have no clue, and to seem to only malfunction when on the road and not when running engine in park now

Oh, only other thing it does strange is now and then, when you turn the key to start it, the starter just clicks , let off and turn it again, and it cranks, I think that is a aged starter tho, but cant see how this could have anything to do with it?. At a loss here....

[jeffcoslacker]

I think the starter issue is a seperate problem.

You didn't mention changing the crank position sensor, which is typical for your symptoms. Lotta times it's easier to change the CPS when you do the IM, they tend to have similar service life.

It sounds like you have the wrong ECM now, did you have to swap the PROM chip into the new one? Something may have gone wrong there...

If it was me I think I'd try to get my old ECM back if possible, and replace the CPS, then see what happens...

[john51md]

Originally Posted by jeffcoslacker

I think the starter issue is a seperate problem.

You didn't mention changing the crank position sensor, which is typical for your symptoms. Lotta times it's easier to change the CPS when you do the IM, they tend to have similar service life.

It sounds like you have the wrong ECM now, did you have to swap the PROM chip into the new one? Something may have gone wrong there...

If it was me I think I'd try to get my old ECM back if possible, and replace the CPS, then see what happens...

Jeff, CPS was changed about a year ago, but it came from ADVANCE AUTO, and ya know their part rep.
I checked ECM numbers, it is the right one, and yes had to swap the prom.I was careful, i have swapped proms before on diff. cars, not really new to this work.
I didnt consider a BAD CPS tho since it was replaced.
You saying a CPS could cause the 'cut off and die" thing and then work after 15 minutes of cooling?
Can i test a CPS? i do have a digital Vt OHM meter

[richtazz]

On the ECM, did you purchase a used one, or a remanufactured one. Since they're under the hood, buying a used one is a bad idea, as they are subjected to water intrusion and it's rare to get a good used one for these cars (especially if the OEM service number is 1227727). If you bought a reman unit, and it is a Cardone brand, don't rule out the ECM as the problem either, as they are known as inferior quality. I would also check the wiring harness that goes from the CKPS to the ICM, as it is routed close to moving parts (RF axle and harmonic balancer), and stuff that gets hot (exhaust manifolds and starter)

[john51md]

Originally Posted by richtazz

On the ECM, did you purchase a used one, or a remanufactured one. Since they're under the hood, buying a used one is a bad idea, as they are subjected to water intrusion and it's rare to get a good used one for these cars (especially if the OEM service number is 1227727). If you bought a reman unit, and it is a Cardone brand, don't rule out the ECM as the problem either, as they are known as inferior quality. I would also check the wiring harness that goes from the CKPS to the ICM, as it is routed close to moving parts (RF axle and harmonic balancer), and stuff that gets hot (exhaust manifolds and starter)

Remanufactured ECM
wiring is ok, i checked that, knew about that problem
remember this is a 2.5 lots more room under hood.

not sure brand of ECm right now, cant go look, if it sasy on it at all, didnt get box with it, they put old ECM in it. i can look online at Advance Auto, it was 78.00 i think

[richtazz]

If you got the ECM from Advance, I believe it would be a Cardone brand, unless they changed suppliers. The only things that could cause a loss of spark at a semi-regular interval are the crank sensor and ICM. The chance that both coils would fail at exactly the same time is almost impossible. There are windings in the CKPS that break down due to heat. ICM's (even new ones) can also heat sink on you and quit. I would also check the connection between the CKPS and coil bracket/ICM for corrosion (as they are bolted together in the back of the block). Since it's a 2.5 (I overlooked that detail, sorry), there is no wiring between the two.

[john51md]

Originally Posted by richtazz

If you got the ECM from Advance, I believe it would be a Cardone brand, unless they changed suppliers. The only things that could cause a loss of spark at a semi-regular interval are the crank sensor and ICM. The chance that both coils would fail at exactly the same time is almost impossible. There are windings in the CKPS that break down due to heat. ICM's (even new ones) can also heat sink on you and quit. I would also check the connection between the CKPS and coil bracket/ICM for corrosion (as they are bolted together in the back of the block). Since it's a 2.5 (I overlooked that detail, sorry), there is no wiring between the two.

Guys, thanks for the help, i dont know of anyhting else to try after what you suggested and i did myself. But i went over everything yesterday again, removing each thing, looking for anything loose or corroded, didnt really see anything suspect. But put it all back and ran car on highway for over a hour and a half and it ran fine, in fact felt a little more powerful and smoother than what it used to.
I dunno, accidently fixed something? cant say. So all i can is over weekend take it out and waste a tank of gas and see if it quits, dont know what elase to do with it but run it and see.
I appreciate all the help here, ill let ya know probably around Monday if it is still alive.

[john51md]

Originally Posted by john51md

91 Lumina 2.5 auto
Stopped at a store about 15 minutes, car shut off. Tried to start it, it just cranked. Tried this about 10 times over 20 minutes, then it instantly started up, seemed fine.

Started home, made it about 10 miles, car dies cleanly on the road. Checked at spark plug, wasnt any fire to any plug. Was almost home so i had brother tow it rest of the way. Car was "off" about 1/2 hour. When we got it into driveway, i hit the key and it started right up.

I put in in my garage, ran it in park about 15 minutes at a higher idle, instantly died, would not restart, it sat for about 15 minutes with hood up, it restarted again. (oh, checked this time as well for fire at plugs, was none)
So... I put a new Ign. modual on it, started right up. Ran it around about a half hour, seemed ok. Loaded wife and 3 yr old granddaughter up, started to town (same store it originally stopped at) ran fine till i got about the same distance from the store, as i did from store to home trip previous night when it quit. Yes it quit again, cut off cleanly in middle of road. Just cranked, no fire at all to plugs.
Had it towed about 2 miles to my sons house, unhooked it, and it started right up. Let it sit there and run about a hour and it didnt shut off. Was afraid to go back out on the road with it, so i left it overnight, trying to decide the cause.

I thought well... this car isnt that techno.. so what is left that can kill it this way? ECM? SO next day i bought a new ECM and put in it, started, ran for over a half hour around his driveway (back and forth) seemed ok, so started home, this time it didnt shut off, it made it home, but has no power, pops up thru intake now and then when you try to accelerate, when slowing trys to miss some, so now its at home, afraid to go back on road with it.
I still cant rule out that it wouldnt shut off and not start again though.

ANyone have any idea's i havent thought of? oh, and plugs, wires, coils are new, all sensors have been replaced over last year or so, charges fine too. I just dont know what else it can be, oh, 2 months ago i also put a new fuel pump, filter, and gas tank on it.

The only code set is has is the same code it has had for the last 4 years, a EGR code, and that is because the EGR doesnt work,(hose plugged) on this the EGR is the simple one hose, no electric wire type like on old GM V8 engines.
Just seems heat related because of stopping almost the same distance i drive it each time. But other than ECM, and Ign. modual, what the heck else could cause a heat issue i have no clue, and to seem to only malfunction when on the road and not when running engine in park now

Oh, only other thing it does strange is now and then, when you turn the key to start it, the starter just clicks , let off and turn it again, and it cranks, I think that is a aged starter tho, but cant see how this could have anything to do with it?. At a loss here....

UPDATE

Well i think i found the problem, after replacing Ign. modual and computer, and it still shut off from what seemed like a het issue, and CPS 'did' check good, i replaced the cps anyway, mainly because when it shut off car was hot, and when checking the CPS, it was cold, anyway.......
What i found was the cps wasnt actually bad, but inside the outer end where the little U shaped springy connector contacts were, one of the 2 contacts had a problem, these look like a "U" lying on it's side, and are springy to maintain contact when the other half of the connector is plugged into them (flat blade) so the top half of one connector "springs" in the CPS was missing, broken off, how i have no idea unless it was from constant heat up and cool down expansion
(( light bulb over head now)) yes, this CPS is mounted on the back of a alumium plate that bolts to the engine, the IGN, modual bolts to the outer side of the alumium plate, when together, the CPS term. shows thru a hole in the alumium plate,and plugs into the back of IGN. modual with a matching terminal (no wiring)
so i believe over time the expansion and contraction of the various parts made the falt U shaped contact to break off, thus when it got hot, expansion made them loose contact. After about 200 miles of driving after replacing CPS, no problems .
Moral of story? never check small parts without your glasses on?

[richtazz]

It's those type of little things that will drive you nuts, especially when working on your own car. Glad to hear you got it fixed, thanks for the feedback.