Truck won't stay running
 

My buddy has a 1997 Ram 1500, and the other night he parked his truck, to come back the next day and find it wouldn't start. So he ended up jump starting the truck to get i running, but once he jump started the truck, it wouldn't stay running. the only way he could keep it running was to keep his foot on the gas pedal. Once he would let off the truck would kill. I was figuring that my friend either has a bad battery, or a charging system that is failing. The truck would stay running, when he would keep his foot on the gas, like he was keeping the rpms up enough for the alternator to produce enough charge to create the enough voltage for the coil to create spark in the engine. I told him to get his battery checked out first on his truck and see if that fixes the problem. Does anyone have any ideas if i'm headed in the right direction here? Or does anyone have any idea what the cause of this problem might be. He's away at school, and i was talking to him over the phone trying to help him out, so any assistance i can get for him asap would be greatly appreciated. Thanks

yeah, battery is the first place to start. I am on the same page as you. probably has a shorted cell. battery is sucking amps.

if he can get it running, take off the negative terminal on the battery if it cuts right out the alternator is shot, if not, dead cell in battery

common problem due to weak battery. when battery voltage is low it plays hell with the reference signals on the TPS and IAC. charge or replace battery.

when a good battery is installed, it should straighten out on its own. if not, just reset the pcm by removing negative battery cable and turning ignition to start for 30 seconds to drain the pcm memory.

i wouldn't do this on a computer controlled engine. you risk damaging the pcm.

instead, test either the battery or alternator output with a voltage meter. if voltage is about 14 volts, alternator is fine.
if lower, alternator might be bad. but, since the pcm has a lot (if not all) to do with voltage regulation, you might have to remove the alternator to fully test it.

it is bad, but a good way to check....sometimes

Totally agree!

I agree..do the battery/alt. test like 95Ram360 said,.. one of them is pooched.

I actually had the same type problem about 11 years ago,..ended up being on the alternator, the "plug-in plug" needed to be swapped out. Same foot on the throttle syndrome to keep it running..exactly. That's because this plug goes,..silently.. then the trucks electronic components..stereos,lights..etc., slowly drain away ALLthe batteries juice...next start...NADA!

I had the same problem last year. I couldn't figure it out, so I had my mechanic look at it. He said it was the IAC so he replaced it. Worked fine for a day and then the problem returned. Took it back to him and he put a new one on, seems the first one he put on burned up the solenoid on it. the second one worked for a day and then it too failed.

Come to find out that the battery had a dead cell in it and was causing a voltage problem, thus burning up the solenoid on the IAC. He put one more IAC, and a new battery in, problem solved!