Installed a new injection pump and injectors. After spending lots of time fixing return line leaks, the truck still idles very rough and misses under maybe 1300-1400 rpm. Runs smooth on the freeway. I haven't had it timed. The guy I bought the pump from said don't bother having it timed if it starts right up and doesn't smoke. I have my doubts on that theory, though. Does this sound like an air intrusion issue or a timing issue? Both? No, the new injectors weren't pop tested. I've put a couple hundred miles on the truck since install.

Any advice appreciated,
Dan

 

Definetaly timing issue, concerning the IP is good. Correct timing is the most important, it is the heart of the engine. Do it correct and then at least u know this is done properly and u can move on if it still does that.

 

Thanks for the advice. I will make an appointment Monday to have it done later next week, hopefully. It's a diesel only shop and it's fairly large, he says that they have all the proper tools and that they don't do it by ear.

The truck is parked anyway for the time being. I found that I have a screw in the dirver rear tire and of course it's right at the start of the tread, too close to the sidewall for the tire shop to agree to repair it. They wen't to swap the spare on for me while I wait for a new tire (warranty), but they stripped a stud on that wheel , so now they gave me a repair order for a local shop to replace the stud. Also, the power steering pressure hose looks to have ruptured. Oh, the holidays .

Dan

 

U can try to give it more advance, just to move the IP, now it is probably too retarded when it misses on idle. If u play with the IP in terms of moving it slightly u should get to the point of running it correct, however the exact timing is still very important. But each engine is little different, nobody knows why, maybe the tolerances, so the factory 8 degrees or whatever the value is is starting point from which u try to advance just a little or retard and after each setting give it a try.Very often u get even better results than factory setting. But if u are not any expert and u do not want to mess with it, just leave it how the shop sets it for u, u should be fine. I do the factory value and then final setting it just on my ear and I get critisized for that with many members, specially in winter it is a good time to do it by ear, when cold u want to hear quite a diesel clatter but not too much and it smoothens when warm. But when u installed new IP and injectors the factory value should be fine. As the used IP gets weak u usually need to give it more advance to be able to get the fuel there the correct time.