Corsica dies after idling,cools then restarts

[RyanC]

Hello-
1996 corsica with 97,000-
Runs great, but if I sit and eat lunch and let it idle it falls on its face and dies -If I try to restart it won't fire. After a half hour it will restart and run fine-
My temp gauge stays consistent at under the 1/2 way mark. I have also smelled coolant many times-
I am planning on replacing the thermostat today to start with, any other ideas, and how to troubleshoot this?

Thanks in advance!
Ryan C

[jsgold]

Can be a lot of things, but, I would recommend removing the ignition module (sits under the coils) and have it tested. They have a habit of doing this very thing. As to the coolant, well, it you smell it I would say it is leaking. Might be a hose, radiator, water pump, or, heater core. If you smell it in the car this is a strong possibility. can have the system tested for pressure leaks to be sure.

[RyanC]

Thank you
I will start with that-

[jsgold]

I left out some information. You can get the module tested at Advance or NAPA, and possibly other parts stores for free. The coils and module usually come off as an assembly. Do not try to remove coils first, a real pain if you do. You also could have a bad crank sensor, but try the module first. Like I said, could be other things but module best bet to start with.

[tazwolf88]

hey my corsica was doing the same thing. mine ended up being a cracked head on the number 3 cylinder. would get water in there then when i shut it off couldn't restart it. give it time for the water to drain out of the cylinder and it would start. not saying that is your problem but it is something to think about. hope it works out for you.

[RyanC]

been out of town for awhile-

I took the module in today and had it tested, it tested ok-
I don't know if i believe that though, since it only fails after long idling sessions-

When I removed the module/coil unit from the block,one of the bolts holding it on had a threaded stud that was missing it's nut,right next to it was a relay looking piece that was supposed to be attached there. I don't know what sensor or what that piece is but maybe it getting bumbed around is part of the problem?

is there something else i should test or replace first,the module is $190.00
might be worth it just so i don't have to take it off twice, back of the block is a terrible place to put it.

thanks
Ryan

[RyanC]

Forgot something important-

had it scanned and the code was -multiple cylinder misfire.

[jsgold]

If you have good fuel pressure I would still lean towards the module or the crank sensor as both will cause this. I have seen a lot of posts here where a module tests good but fails when heated up. I hate to tell you to throw money at it, but unsure of any way to be sure except to replace it, maybe with a used one at first. They used these same modules even on 2000+ model cars. Might get a inline spark checker and run the engine until hot and see if it is firing well, or perhaps the one that NAPA has that looks like a spark plug you clip onto the frame and run a plug wire to. I am facing a new problem on our 91 where is has a similar problem to you except that it does not stall out, but rather starts to miss badly at random times when hot. I suspect one of the coils is failing but have to narrow the firing down to be sure.

[RyanC]

Well I got a module off ebay and it seemed to be the right fix. Then it got snowy and cold out and I didn't drive it for a week. It was hard to start but did, then another few days and it was dead. I thought it was frozen so i put it in the garage. it's been in the warm garage for a week now and I can't get it to fire at all. i don't have a spark checker but I took out a plug, grounded it with a wire and I did see spark. I have checked all fuses i can find. I suspect the fuel pump since it was low on gas, frozen in the driveway. I don't know how to check much else- I 'm going to have a friend listen for the pump coming on in the tank.

any other ideas would be great.

thanks
Ryan -

[jsgold]

You really need to check the fuel pressure, even if you do hear the pump kick on. It should kick on for 2 sec, then turns off if the car is not started. My Corsica requires close to 40 lbs of pressure, otherwise it won't run. Also, if yo bought a used module, it could be weak. What you should be able to see is a spark that can jump 1-2", or a fat blue spark at plug. Possible your crank sensor is bad, also very common problem. It tells the computer when to fire, if it is cracked or weak it could be a problem. My friend had an 88 model that had BOTH failing. It is generally cheap to replace, but sometimes a pain to get to. Not sure where yours is, usually they are in the front of the motor near the crank pulley. Getting back to the fuel pressure, if you do not hear a pump kick on at all you could have a pump relay sticking too. Had this happen on ours this past summer. There are usually three relays on the firewall, on of which is the fuel pump relay. Cheap and easy to fix. usually you have random starting when this starts to fail. Would suggest a manual, and either borrow or buy a fuel pressure tester. Advance Auto might loan or lease you one. If your pressure is low, might be a clogged filter or bad pump.

[RyanC]

I just had a small blue spark. I think I will switch to the old module to start with, if it still won't fire I will get a fuel pressure tester.
thanks again.
RC

[RyanC]

I have a manual and it shows a valve for testing fuel pressure, I can't find it for the life of me. Where the heck is it, or does a 96 not have one?
I could use some help,I'm lost-
RC

[jsgold]

Good question. On my 91 it is in plain sight but it is a mutil port engine, yours is not. We just bought a 95 Beretta, same engine as yours I am sure. I will check the engine and GM manual for it when I get home later this evening.

[jsgold]

Pretty sure your motor is the same as this 95, so look behind the power steering pump, you should see the fuel rail end there with a connector on it that is hopefully covered by a cap that looks like a tire valve cap. Remove the cap, connect the fuel pressure tester and then turn the key on, but do not try to start. The fuel pressure should go to 41-47 lbs and then the pump should kick off after 2 sec. The pressure should stay there though for a while. Then release the tester bleed hose into a container and unhook the tester. Be SURE to exercise extreme caution when doing this, never test a hot engine, be sure to wrap a small towel or cloth around the connector when unhooking or have one on it already after hooking up as the gas can leak a little while testing and will for sure when unhooking the tester even after releasing the pressure. Also, be sure you are in a well ventilated area when doing this. Check your manual, it should have the procedure in it. Be sure to put the plastic cap back on afterwards. If the pressure does nothing then you either have a bad pump or a bad relay.

[RyanC]

Well the fuel pressure valve could not be found, me and a friend looked for a long time-
I did put my ear to the tank and heard nothing at all when the key was turned on.
Also my manual shows a fuel pump test lead,I can't find that either.all fuses are good that I can find.

I'm not sure what to do next, ideas?