check for a vacuum leakthe gasket under the tbi blows and cause that also check the hose going to the map sensor on firewall, if it's soft get anew one because it may be sucking together not allowing map to work right. check fuel pressure it should be 9-11 psi.

Answered by hmac300 (expert)
18,721 answers provided

Had a mechanic check all pressure, and timing says it's running perfect. The hose on the map sensor is hard as a rock. My cold air k&n intake is missing a stud because of the install before I had the truck. The hole for the stud is about a quarter of an inch. I took the throttle body off the truck and cleaned regasketed and added new filters to the fuel injectors.

Response from zdaily
5 questions asked

if the hose is hard as arock it shold be like anew piece of vacuum hose replace. is it leaking ari around the stud ? it shouldn't otherwise that will cause problems for maf. the pcm shold be in the kick panel on passenger side but dont' think that is the problem it might be a prom but that should show up when scanned. and you probably can't get another prom now anyhow due to age.can't offer any other suggestions on this one.

Answered by hmac300 (expert)
18,721 answers provided