Ok, I have been trying to figure this out for a while, but I am getting nowhere fast, and I wanted to see if you fine folks could help me out with this. When I go to start up my truck, more often then not it will have trouble firing up. Letting it run won't help it run smoothly, so I usually have to try and start it a few times. A few months ago I put some injector cleaner in it thinking that it might be dirty injectors. That cleared things up for a while, but now with colder weather it seems to be acting up again. Could it still be bad injectors? The previous owner rebuilt the engine, but told me that he didn't replace the injectors.

P.S. I installed a new fuel filter in it a couple months ago (think that could have been the problem as well.

 

I've heard of people replacing the injectors with Chrysler 703s and that clearing up the problems like you described.

 

will idle smooth out above a certain rpm?

 

What is condition of plugs wires etc. have you checked fuel pressure what year is your jeep eng size. Most repair shops offer complete fuel system cleaning where they disable fuel pump and hook a pressureized fuel system cleaning the engine runs off of the can of cleaner untill can is empty.this method is very effective. I would recomend you find a napa auto care center in your area and talk to them.

 

Sorry I didn't put down additional info. Its an 87 4.0. The previous owner put in new plugs and wires, and they look like they're in good shape. When it starts rough it doesnt smooth out until I hit around 2500 rpm. If the truck is warm it's much easier to start. Sometimes I can get it to start right away and sometimes it can take ten minutes. If I can think of anything else I will post it n

 

Clean TB and Idle air control motor very good, and c i it changes.