So my neighbor just a 1990 454 ss and knows nothing about trucks or cars or women.....I have been goin through the electrical system for 2 days now and found nothing wrong. Heres the prob the damn thing decides to run ok for about 2 minutes then wont go over 10mph then runs ok again. My only option is to take it to the dealer and have a good diagnostic done to it, would that be yalls suggestion or if anyone has had this problem and could help thanks.

 

I would go to Autozone and have them check the codes. Dont expect much the computers on older trucks are not very descriptive with the codes. I would look at the plugs and see if they look like it is running lean. You may have fuel pressure issues. Has the truck had a tune up lately? I would cover the basics with a cap rotor and plugs. Also did it sit up before it was purchased? The fuel could be bad.

 

Complete tune up has been done wires cap fuel o2 sensor oil etc, idles great and revs up smooth but at high rpm backfires and blow back outta tbi. Gonna get the diagnostic from a friend at the dealership this weekend just askin u guys first thanks again

 

Bout to tell him to go carburated like my first thought what would be a good set up for that

 

check the timing, adjust the rocker arms.....


is the truck stock or does it have aftermarket parts on it?

 

Bone stock, why should i do timing doesnt the comp. tell it what to do, and i have checked the rockers and adjusted the distr. i have no idea, thats why im gettin the ecm plugged up this weekend and ill let u guys know all the probs for ***** and giggles. If it comes down to it though does anyone recommend a good set up to go carbed and what is needed for this motor?

 

trouble starting? hesitating? any of that good stuff leading to spark? coil maybe?

also how about the fuel pump? factory?

 

Sounds fuel related to me. I would get a fuel pressure gauge on it and see what it is doing.

 

the timing needs to be set, just like a carburated engine. mine was doing something similar when i bought it and it ended up being the coil so i would check it also


i have a brand new 700hp 496 stroker with an accel MPFI and FAST computer for sale. its still at the machine shop. i'll go pick it up, all you need to do is put the accessories on it and tune the computer......$5000 for everything

 

There is two timing adjustments....one is in the tune and the other is the initial timing set by the distributor like a carb. These engines are set to '0' degrees advanced I believe for the 454...I know the 350 is '0'. Once timing is done, have you changed the fuel filter and rotor button? Also, does it use any coolant? Another thought, have you done a compression test?