I have a 8.3 Cummins that has some white smoke at idle, so I cracked open the injector lines to see if I could find a week or dead cylinder and stop the smoke. I cracked the lines open the motor goes into a heavy miss close the lines motor picks up almost instantly. except number 5 when you crack number 5 the motor starts to miss just like all the other cylinders but when you close it, it takes 5 seconds or so to pick up and run right. So my question is do you think the problem with #5 is the injector or injector pump or other. the motor is a 1990 8.3 Cummins with a bosch A type pump. its in a td15c. the motor has high hours and the injectors or pump have never been touched. THANKS for your help.
First thing I'd do is swap two injectors and see if the problem moves to the new cylinder where the previous #5 injector is now. If if stays on #5 then you can start looking at the pump or figure out if that hole has internal issues. Greyson
thanks for the reply gterminin. I started pulling the injectors after I posted. I think I'm going to take the injectors in and have them tested and that will tell the hole story. talked to the pump shop on the phone and he said it sounds more like a injector then the pump.
Those 8.3 in the magnum tractors when they get to about 4500 hours we change injectors. Seen several that didn't and burnt hole down side of piston. Operator usually doesn't notice miss (sometimes slight) and before you no it has extreme blowby. Sometimes they test ok when cold.
I'm with you Dirt.. Get all the tips replaced.. cheap insurance.. Costs a couple of hundred but compared to a couple of thousand.. sounds pretty good.. Same goes with the fuel filters.. 20.00 a couple of times a year can save you thousands in pump work. Not to mention down time.
just got back from the injector pump shop. 1 injector was good, 2 would hold pressure but a little below spec, 2 held pressure but were way low, and number 5 would only hold 200 to 300 psi. the pump guy said I'm pretty sure you have a injector problem not a pump problem. it was definitely worth the 1 hour drive one way to no exactly what was going on. I should have my injectors back by tomorrow end of day. I guess I waited wayyyyy! to long to change them. but the old girl would fire right up on a 10 deg day and seemed to run just fine with a little white smoke at idle. you no how it is there always something broke or needs your attention worse. td15