# [SOLVED] chevy 1500 backfire



## redchevyz71

when I accelerate quickly or matt it the truck will back fire through the tbi and will either stall completely or spit and sputter then get up to speed. Any ideas? I thought maybe the fuel pump or the timing is off


----------



## octaneman

*Re: chevy 1500 backfire*

Timing is definitely off but it's also a sign of a bigger problem that the chain has jumped a tooth.


----------



## dkan33

*Re: chevy 1500 backfire*

Could also be a lifter ,rocker arm or poss. worn cam . year and eng. info would be helpful . many factors can cause this type of problem .


Gm tech 40yrs.


----------



## redchevyz71

Its a 94 5.7l 350 with 135k miles. I'm going to check the timing and fuel pressure regulator tonight but I don't think its too serious considering it runs fine as long as you aren't stomping on the pedal


----------



## kjms1

*Re: chevy 1500 backfire*



redchevyz71 said:


> Its a 94 5.7l 350 with 135k miles. but I don't think its too serious considering it runs fine as long as you aren't stomping on the pedal


yeah hope for the best and aspect the worse 
old rule of thumb 
If it back fires thru the carb its timing or valve train
If it back fires thru the exhaust its the carb or valve train
granted that applies if you got the spark plug wires right LOL

a timing chain will not act up as much when your babying the truck but goose it and the chain wipes


----------



## redchevyz71

Sorry its been a while since I've responded but I fixed the timing and it still does it just not as often. Only when I mat it when its below 1500 rpm. How hard is it to check the timing chain?


----------



## kjms1

*Re: chevy 1500 backfire*

not hard at all just takes 2 ppl
remove the dist cap with a socket on a breaker bar connected to the crank shaft front bolt turn it backwards a little when the second guy sees the rotor turn you can stop mark the balancer with a reference point on the timing mark... now turn it back the other way slowly and when the other guy sees the rotor start to move stop .. then look and see how far the reference mark has moved in degrees or in inches 1/4 ect 

1/2" play in the chain it is starting to get bad an inches and jumping a tooth is about to happen


----------



## redchevyz71

Okay thanks I'm goin to try that this weekend. But I have been told that if my chain was done the truck wouldn't run at all or barely run so I have my doubts


----------



## redchevyz71

So I replace the whole injector assembly which includes injectors and fuel pressure regulator and I think that did it. Call this one solved


----------

