Some of you may have aready read my other post about replacing the computer in a 90 Ranger 4.0. Well I decided to try some cheap and simple stuff first. I went through a cleaned the MAF, replaced the air filter, I also added a few more ground wires/ cables. I ran one from the engine block to the frame, one from cab to the frame, and a smaller wire from the inner fender to the neg. side of the battery. The truck seems to start easier and runs smoother and quieter than before. However if you run it, shut it down, and restart it, it sputters and runs a bit rough. Not completely sure where to go from here, any ideas?
John

 

Sticky IAC? Idle Air Control could be gummy and not readily able to open up enough after shutdown. It has to be pretty reactive to command to keep the idle steady. If you had a leaky injector it could be flooding the intake. Try pushing a bit on the gas pedal to see if it will start and run smoothly with a bit more air coming in.
tom

 

I just replaced the IAC tonight, a fresh set of plugs, and added a Performance Distributors Screamin Demon coil pack. It definately starts quicker and runs smoother; seems a bit more responsive. I did end up replacing all the injectors last fall, a couple of them were leaking. I'm not sure, this thing still kind of a slug. I've done everything I can think of for it, it just feels slow. A buddy of mine has a 93 SC SB Ranger 4x4 with the 4.0/ 5 speed... that thing will run circles around this one. Of course this truck has an auto... which typically does rob some power. Any other ideas why this thing is such a turd?
John