HELP PLEASE, my 92 deville 4.9 just started to have this problem. while driving or at a idle it will shut off (engine and all) no power at all on the dash radio or anything and then restarts by itself all within 1 second or less. It did die one time where I had to restart it with the key and it started right back up. I am thinking bad ground somewhere?
:hmm:
One other problem also. When coming to a stop the rpm's go very low and the back up to normal then very low again and so on and so on. Some times the rpms go so low it stalls. any ideas anyone. thanks

HELP PLEASE, my 92 deville 4.9 just started to have this problem. while driving or at a idle it will shut off (engine and all) no power at all on the dash radio or anything and then restarts by itself all within 1 second or less. It did die one time where I had to restart it with the key and it started right back up. I am thinking bad ground somewhere?
:hmm:
One other problem also. When coming to a stop the rpm's go very low and the back up to normal then very low again and so on and so on. Some times the rpms go so low it stalls. any ideas anyone. thanks
:lildevil:it sounds like a priest could help your car...:angel: but i would try this, do an on-board check like this; turn the key to the on position, but do not fire the engine. locate the climate controll panel and look for the OFF and WARMER buttons on that device. once located, press both at the same time untill you see all the dash lights and such come on all at once, then look to your fuel data center (on a deville i believe) and you will notice it showing a set of letter and number codes. the numbers will look something like this ..e052. once you see these, copy them down and post them here on this thread, and someone will be able to help from there. or you could call a certified priest and be done with it...:halo: good luck dude.

low RPM to stall in idle sounds like the Idle Speed Control (ISC) motor to me.. not sure why it restarts itself. Maybe an ignition wire. or ground. no clue.

HI the code is E71 which in my manual, say M.a.p sensor. I dont think that would cause the car to shut off then back on. any other ideas?:hmm:

i think you should replace that map sensor just to be sure. but the problem at hand sounds like your idle speed controll motor is the real problem. sometimes, in my experience, those can go bad without setting any codes off at all. also, check the associated wirng to see if that is bad too. good luck.

HI, are you saying the idle speed on control might cause a car to shut off then restart itself? I just dont see how? anything is possible I guess.
thanks for your help

HI, are you saying the idle speed on control might cause a car to shut off then restart itself? I just dont see how? anything is possible I guess.
thanks for your help

maybe your ecm is messed up or something. when the car turns off, are you sure that the rpms just dont go real low, then return to normal, making it appear that the car is off? because if the rpms go too low, it may seem that the engine is not running for a moment, as though it was stumbling. also, check you ignition switch and related wiring, could be a bad connection there causing that too. try this, spray some electrical contact cleaner into the key cylinder, let it dry and see if that helps. good luck.

i forgot to ask, does your ride have a remote start? if so, that could be the problem too.

Since you said the lights go off on everything including the radio I would check the battery cables. You have two positive cables on the battery and corrosion builds up between the two causing erratic problems like this. Take them off and pull the two apart then use a wire brush to clean everything up. Hope this helps.

Steve B.

Everyone thanks for your sugestions. Yes the car engine dies completly because I had to restart it once by the key. It seems to die then restart very quickly. Also when I was trying to find the problem the other night, the battery acted like it was very dead. Very dim head lights and dash lights. Aslo the radio lost all of the sation presets. Then I turn the key again and boom all back to normal, bight lights and bright dash light. I took it by autozone to have the battery check. The battery and alternater checked out fine. I have not have a chance yet to take the two postive cables appart and check for corrotion. I had a friend at work say to check the igintion switch down low on top of the steering column. I will do that this weekend also. The car does have an aftermarket alarm that was on it when I bought it but it just unlocks and locks the doors and siren when the doors open no remote start. I drove it today to work with no problems. It seems t be a problem off and on. I will check all of the above this weekend and thanks everyone for your sugestions.

if none of these things work, ill will post some numbers to a few certified priests...i know they can help your "car" :lildevil:

The car does have an aftermarket alarm that was on it when I bought it but it just unlocks and locks the doors and siren when the doors open no remote start.

The majority of alarm systems also include a starter interlock system. These are notorious for causing lots of problems. I never fail to be amazed at the ineptitude of the majority of these installations. Most shops just hack the main ignition wire to the starter so that you can't just remove/disable the system & still start the car. Obviously partially effective in preventing auto theft but sure makes our lives a bitch when they fail -- & they almost always do.

I'd agree with it being somewhere in the ignition wiring. I don't know about the dim lights part about it but you can mimic your situation in any car by quickly turning your key off and back on quickly. It will die but the engine will just be spinning enough when you switch the key back on and the power comes back that it will begin running again, except for the time where the power dissapered for too long and you had to restart it.

I think it a stems down to a bad connection somewhere, the dim lights would be from when it is almost a broken connection, say a little power is managing to get through some corrosion, and when it quits, the connection is totally broken. Mabey it is vibration induced, rattaling a poorly made connection in a wire, or your ignition switch, as your friend suggested.