Car wont start after a while.

[jeffreyinigo]

Well I was driving home from changing my headgasket just trying to drive it nice and slow. A friend and me did it together.Suddenly the car just automatically shuts off. Lights, everything included. Well then I noticed that the positive battery terminal was completely off. I connected it and tried to start it, nothing. It turned over but it didnt start. The lights came on and everything, just the car wouldnt start

I let it sit for about a half hour and tried to start it again. It started up fine and was about to get home, when it stopped again. This time the battery stayed connected, again I let it sit for about a half hour and started it up just fine. It was dark so I wasnt able to check anything on it. I noticed the next morning that it started up fine and that the night before when I tried to start it, there was no spark. So we tried to find out what was wrong with it today, but couldnt figure it out. We turned it on in the morning and let it sit for a while, everything was fine until i tried to drive it,it just shut off and again no spark. I let it sit for long time (3 hours) and tried to start it, but no start. I guess it gave up. Anybody have any ideas what it could be??????
Thanks guys.

 

[yekrahs]

Check your MPI fuse and all of your other fuses thats a good way to start. What spark plugs are you running you could have fouled one or all of your spark plugs. Get a multimeter and test your coil pack too.

 

[jeffreyinigo]

The mpi fuse is fine and the spark plugs are fairly new. they are ngks and i will test the coilpack this week. any other info or ideas can be greatly useful. thanks. keep the ideas coming guys

 

[luv2rallye]

A battery that is not tied down is known to short against the hood on these cars which kills it. Does it only happen while moving?

 

[jeffreyinigo]

well. yeah. but it just started to happen recently. i dont know whats up with it. but then it doesnt spark anymore once you try to turn it on. it just died.

 

[luv2rallye]

Check if MPI relay is intermittent or has poor connector.

 

[jeffreyinigo]

mmmmmmmm. sorry how do i do that? i guess im kinda new with this. is the relay the same one as the fuse thats on the battery terminal? and what do you mean by intermittent and if it has a bad connector?

 

[95talon_in_ma]

Did you connect your ground cable back up to the engine?
I had a camaro once that used the shifter cable as a ground and eventually fried 3 cables in a row before I figured out it was the ground strap.

 

[luv2rallye]

Yes the grounds are important as he says and should be the first thing to check. There must be a securely tightened cable going from the battery negative to both the engine block and the car body.

No the relay is not the same as the fuse. By bad connector I mean if the wire harness connector to the MPI relay has fallen off, loose, is full of mud, contacts are corroded, wires broken, etc (anything that would make a poor electrical connection).

By intermittent I mean the relay doesn't always work properly, sometimes yes and sometimes no, usually due to poor or worn out internal contacts inside it. The relay then needs replacing. The relay controls power to all the engine electrical stuff (injectors, sensors, solenoids, etc and the MPU which controls ignition coils and fuel pump relay) so if it's bad the engine will not run. See here for it's location (says MPI on it): http://members.shaw.ca/dsm.1000q/Engineprimer/1G/relaybox.htm. If you have a multimeter you can check if you get +12 volts on it's red wire (also on the oxygen sensor red heater wire) when the key is turned on. You can stick a safety pin through it's insulation to get at it for measuring.

 

[jeffreyinigo]

ok. a friend of mine also told me that it could be the cam angle sensor or the ecu. i thought it would be the coil or something like that? any of this possible. and also, i have a 90 awd talon that has the cas and the power transistor and stuff. are these compatible with the 92? The cas doesnt have the same connector as the 90 on the cas and was wondering if i could just splice the wires to connect it. would this be a possibility?

 

[luv2rallye]

The CAS is different on the 90 (as are the coil and power transistor) but see here for more: http://www.dsmtuners.com/forums/showthread.php?t=227927.

Since you claim it runs fine until warm and then no spark, it would seem you have a temperature problem with either the power transistor, ECU, or coil. Start when cold and it runs fine and then put a heat gun (or hairdryer) on each of those to see if it causes the problem.

 

[jeffreyinigo]

Heyyyyyyyy guys thanks a lot. it was the cas. It seem that water got into the one i had on there. i just dont know how. but it was the cas. got it running right again. thanks guys