7.3 IDI Bad Injector? How do I check it? - Diesel Forum

c21no1 · 05-10-2005, 11:00 AM

I have a 7.3 Diesel in my 1986 IH Dump Truck, you guys have helped me out a lot on both of my powerstroke engines, so I thought I'd throw this out there. I just bought this truck, it has 94K on it, just had new head gaskets done, but it smokes a lot at start up until warm, and when warm, it has a miss at higher RPM's. I was told it's probably a bad injector, but how can I tell if it is and if so, which one? It also is governed to 55mph, how can I turn that up? I do have a good fuel system from a 1984 6.9 out of a F-350 if the injectors are the same I could swap them out. Any help would be greatly appreciated.

Thanks
Dan

icanfixall · 05-10-2005, 03:30 PM

About the easiest way to check a bad injector is to have them pop tested. Remove them and take them to a injector and injection pump repair shop and ask. Most will do it for free or if they are ok the charge is very small. A complete new set is about $175.00 to $240.00 so if someone wants $50.00 to test them just buy a new not rebuilt set or find another shop. Out where you can't find a shop just remove the suspect injector and swap it with another one that you know is good and see if the miss follows and now is in another cylinder. The copper gaskets will need to be replaced because once you torque them down to 35 lbs and they heat up they will work harden. Some have tried to reuse them with many-o-problems like lots of carbon leaking past the gasket and freezing the injector in the head. This wont happen in a few hundred miles but why take that chance.

c21no1 · 05-11-2005, 09:41 AM

Do you think the injectors from my 6.9 are the same? I know they are all good, that engine had a bent rod from some idiot flooding it with starting fluid. Thanks for the help.