its happened 4 times already today. after accelerating up hill and then letting off it just shuts off. i prevented it from happening again just now by revving it when i felt it bogging down.


my truck needs a new rear main seal so when my old level is down i add oil. i recently added a quart of 10w40 to it and thats when it started happening. i ussually run 5w30 in it.

when it shuts off, the oil light goes on, but it doesnt stay on when that truck is on. and thats the only thing that happens. there is no CEL on.

it fires up first time all the time, even after it dies.

my oil level is fine now.


anybody out there with the same problem or experienced the same problem.


oh and my truck is a 97 1500 with the 5.9l and about 142k miles.

 

Probably IAC motor, or TPS.

Oil grade will have no effect here. (at least, not in this case.... )

Try cleaning your throttle body first, pull the IAC out, and clean those passages VERY well.

 

or a fuel pump maybe?

 

I agree. Sluggish IAC not compensating fast enough, but getting back to where it should be by the time you crank again. Could be a failing motor, or just a really gummed-up pintle and throttle body passage. Clean first, see what happens

 

new update.

when starting my truck, everytime whether warm or cold, my rpm's will rise to a little over 1000 then drop to lower thn 200. it will only last there for a second before rising back to 800 rpms.


also, when driving, if i let off the gas, sometimes, but not always the rpms will drop to 200.

 

Did you check the IAC as we've suggested?

Could also be a vacuum leak.