hey all

got a 1990 ram v6 3.9

sometimes it does not start, this only happens when driving around first. cold starts every time.

when it will not start, LOUD pops will come from under hood when cranking

had somone else start, notice that the sound is the houses coming from the valve covers into intake/carb/throttle popping off, then another pop and the intake filter and all JUMPS off the carb.

any idea what is going on?

 

It is backfiring through the tbi/throttle body.
So will not start hot? Do you have a check engine light?
Have seen a coolant temp sensor cause this.

 

im guessing your truck has dirty spark plugs. get em check or replaced, if you can get at em its pretty cheap

 

I think its problem of spark plug. Just change your spark plug and check .

 

damn sure its because of the spark plugs, get them replaced. it will surely sort this thing out.

 

Such problem mostly use to occur due to the rust in the engine part.