Testing Diesel Fuel Injectors

jlemaire1 · February 18, 2010

i was wondering is there a way to test or diagnose fuel injectors on a duramax without pulling them.i know it's a long shot but any help would be appreciated.the truck is smoking pretty good at idle and my service engine light came on and it says i have a bad glow plug.i will be testing and replacing the bad glow plug soon,i don't believe this would cause my engine to smoke at idle but i'm new to the duramax engine.also it is a 01 2500 4x4 if that helps.

redvett · February 20, 2010

No you will need to remove them and take them to a Diesel shop that can test them.

Silverado4x4 · February 20, 2010

Smoking at idle tells you that you have bad injectors, your out of the extended injector warrenty 7yr/200,000 mile GM put out to cover this being you have a 2001. Be ready for a big bill on the replacement as you have the LB7 motor and the injectors are internal and everything on top of the valve cover have to be removed then the valve cover has to come off look for around $2000.00 or more for them to do it.

Nytemare · February 21, 2010

Smoking at idle tells you that you have bad injectors, your out of the extended injector warrenty 7yr/200,000 mile GM put out to cover this being you have a 2001. Be ready for a big bill on the replacement as you have the LB7 motor and the injectors are internal and everything on top of the valve cover have to be removed then the valve cover has to come off look for around $2000.00 or more for them to do it.

I have heard most guys up this way say its 3200 bones tax inc.

desrtrat · February 21, 2010

Smoking at idle tells you that you have bad injectors, your out of the extended injector warrenty 7yr/200,000 mile GM put out to cover this being you have a 2001. Be ready for a big bill on the replacement as you have the LB7 motor and the injectors are internal and everything on top of the valve cover have to be removed then the valve cover has to come off look for around $2000.00 or more for them to do it.

I have heard most guys up this way say its 3200 bones tax inc.

i was at the dealer last week, and a kid there had the same issues. dealer quote was $4000

something to try. change your fuel filter and instead if filling it with diesel fuel, completely fill the filter with Lucas fuel injector cleaner. maybe your injectors are just dirty. have done this with out HD trucks at work on every fuel filter change..

good luck

Nytemare · February 22, 2010

Smoking at idle tells you that you have bad injectors, your out of the extended injector warrenty 7yr/200,000 mile GM put out to cover this being you have a 2001. Be ready for a big bill on the replacement as you have the LB7 motor and the injectors are internal and everything on top of the valve cover have to be removed then the valve cover has to come off look for around $2000.00 or more for them to do it.

I have heard most guys up this way say its 3200 bones tax inc.

i was at the dealer last week, and a kid there had the same issues. dealer quote was $4000

something to try. change your fuel filter and instead if filling it with diesel fuel, completely fill the filter with Lucas fuel injector cleaner. maybe your injectors are just dirty. have done this with out HD trucks at work on every fuel filter change..

good luck

Anything is worth a try before you dish out 4000 bucks...holy shit

Is there any adjustment on the injector pump on the LB7 engines like with the old Cummins. It could just need to have the fuel pressure adjusted if this were the case. Not really up on diesels...I can do basic troublshooting and mechanical work on them but thats as far as it goes for me.