injector questions
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More Turbo
Joined: Apr 2009
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injector questions
Hey guys I've been wondering what tell tale signs there would be to know you have a bad injector or an injector thats on its way out? I know by working in the diesel field that on our equipment with 3 or 4 cylinders that if one is bad it will run like hell. but im not to sure about the 7.3 and if one is starting how will you know? I asked my snap on dealer if there was anything else that could do a buzz test but he told me just the full blown scanner can do it. Is ther another way of doing the test or should i just have the dealer do it??
Thank you,
-AJ
Thank you,
-AJ
Cargo Master
Joined: May 2010
Posts: 3,047
Likes: 10
From: Snohomish, WA
Software like Autoenginuity can do it. You Can pick it up from Clay for $360. It is the best deal that you can buy for under $400 to accomplish full diagnostics.
Riffraff Diesel: AutoEnginuity Total Ford Enhanced Bundle
You can also do the buzz test with the Aeroforce Scangauge. It has the test built into it.
Riffraff Diesel: AutoEnginuity Total Ford Enhanced Bundle
You can also do the buzz test with the Aeroforce Scangauge. It has the test built into it.
Senior User
Joined: Jun 2010
Posts: 138
Likes: 2
From: Homestead
Buzz test the injector followed by a Koeo test record the results .....usually the injector problem is related to wiring ....ither under valve cover harness fails in some way or the solenoid on the injector fails ..... ..... But before anything else you need those codes so you can isolate the the problem to a bank and then to a cylinder . Post the codes you find so we can better help you .
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More Turbo
Joined: Apr 2009
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But do i use the software that woodsandthings posted about to do those tests? And are there any signs that may lead me in the direction of a bad injector or injectors? It seems to run fine but i guess im just very **** about my truck.
Post Fiend
Joined: May 2009
Posts: 5,470
Likes: 3
From: Pea Ridge, AR
Yes AE can do the BUZZ and CCT(Cylinder Contribution) as well as anything else you would need or want to electrically diagnose, the only real way to fully test the injectors would be to send them off for flow testing Riffraff Diesel: 7.3L HEUI Injector Flow Testing
If you are not having hard starts or not starting without being plugged in, missing, or shaking when the TC lockup happens at low load situations, and no SES lights I wouldn't worry until you do.
If you are not having hard starts or not starting without being plugged in, missing, or shaking when the TC lockup happens at low load situations, and no SES lights I wouldn't worry until you do.
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More Turbo
Joined: Apr 2009
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The other day I had the truck bumped up with my chip on high idle and it sounded like it was starting to miss slightly and then normal and it did this for a little but then quieted down. I'm probably just worrying about nothing. Thank you for the help. Ill be picking up AE very soon. Ill have questions once I do get it. Haha.
Thank you,
-AJ
Thank you,
-AJ
Post Fiend
Joined: Jun 2004
Posts: 9,293
Likes: 10
From: Parker, CO
Actually.... I've never seen AE accurately diagnose a bad injector.
Rotational velocity tests and contribution tests can only tell you if there is an imbalance, but it can't accurately tell you if it's an injector problem, or even exactly which cylinder it is. It might point to one (or multiple) cylinders, but it doesn't tell you if the one firing ahead of it is the actual culprit.
Then the buzz test only checks the electrical side. If you have a wiring problem, then you can pinpont it using a buzz test. But if the injector itself is mechanically at fault, it's not going to tell you with a buzz test. Plus it's rare for an injector solenoid to fail.
I've replaced bad injectors on my truck, and I found them to be bad when the engine was running with the valve covers off, and oil pissing out the top past the poppet... all the while knocking as if someone was taking a sledge to the side of the block. Yet AE never once failed the injectors, or even the cylinders, associated with the problem.
Rotational velocity tests and contribution tests can only tell you if there is an imbalance, but it can't accurately tell you if it's an injector problem, or even exactly which cylinder it is. It might point to one (or multiple) cylinders, but it doesn't tell you if the one firing ahead of it is the actual culprit.
Then the buzz test only checks the electrical side. If you have a wiring problem, then you can pinpont it using a buzz test. But if the injector itself is mechanically at fault, it's not going to tell you with a buzz test. Plus it's rare for an injector solenoid to fail.
I've replaced bad injectors on my truck, and I found them to be bad when the engine was running with the valve covers off, and oil pissing out the top past the poppet... all the while knocking as if someone was taking a sledge to the side of the block. Yet AE never once failed the injectors, or even the cylinders, associated with the problem.
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