I have a 1989 d150 318 v8 auto. An I've had problems every since I got it. It has 60k miles on it factory AC still works. Still has the smog pump but not the belt for it. It runs good one day an next day won't hardly start. Or I l be in town an It just go to running like crap. Won't hardly idle an u have to pump the gas to even get it to rev up. If u just drop the throttle it dies. If I slowly let the rims fall it will bounce around in idle an then just sit an run bad. I've pulled the tank . Swapped the coil. It has new plugs an wires dis. Cap an rotor. I thought maybe a vacuum leak so I sprayed around to see an the throttle body gaskets wer leaking so I've rebuilt the tbi. Started it this morning it ran fine til I got to work. Went to go home an it wudnt hardly run. I've checked the wiring by moving it around. An nothing... also it smells like its running rich. is it my ecm ???

 

Did you check fuel pressure? Idle motor on these are known to go bad, If the rpms drop at idle and you can keep it up by putting you foot on the gas it's bad. Also look at the injectors and see if both are firing.

 

i havnt checked fuel pressure yet. i do know im getting fuel to the tbi, ive been in the process of rigging an adapter to fit the fuel line to check it. also its not just an idle problem. wen its running bad i have to pump the heck out of the peddle to get the rpms up. even then its spitting an sputtering. i will check the fuel psi in just a little while.

 

ok well i got a tee tied in on my pressure gauge hooked it up an when i hit the key the gauge never moved from zero....

 

Cycle the key a couple times, and see if pressure comes up.

 

i cycled the key several times and it still didnt move. but i did get it to start. with my gauge on it an it reads 10lbs give it some throttle an it drops more.

 

Time for a new pump......

 

I’ll second that as both of my 89’s have close to 15psi key on and never below 13psi under load