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4 bad fuel injectors?

1736 Views 4 Replies 3 Participants Last post by  budman451
Hey everybody. This is my 1st post here so please excuse my limited knowledge of the subject.

We just got a 2001 F550 powerstroke where I work & we're having a breakdown & possible injector problem. Prior to the truck breaking down the exhaust was pushing out a pretty excessive amount of white-ish smoke that would eventually clear up but would take 15 or 20 minutes to clear. This looked like partially-burned fuel in the exhaust but could be something else. One of our guys was driving it recently & it coughed a big shot of white smoke & the engine stalled & will not restart. We had a local auto/truck mechanic install his OTC genisis scan tool & he found no error codes. He tried to do an injector buzz test & found that 4 of the injectors were not responding. Injectors 1, 2, 4 & 5 I believe. His conclusion was that those 4 injectors were bad & needed to be replaced but recommended we just replace all 8 saying the others were probably close to the same condition. It seemed odd that 4 injectors would crap out at once so I wanted to see if anyone here had similiar issues. If anyone can offer any insight or ideas I'd really appreciate it.
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Buddy's quicker than me on this one /ubbthreads/images/graemlins/grin.gif

let me expound on Buddy's reply to ensure you know what he's talking about. There are 3 different sources for the problems you are describing, all having to do with the wires leading to the injectors.

1) The easiest place to check first is where the bundle of wires goes from the fender on the drivers side over the top of the valve covers on the driver's side. The wires here have a tendency to chaff and short out. BE CAREFUL! These injectors run at 120 volts, it will give ya a jolt if you find the short w/your fingers /ubbthreads/images/graemlins/smile.gif Use an insulated stick of sorts to move the wiring harness on the valve cover (VC) and see if it clears up how the engine is running.

2) The injectors are located under the valve covers. There is a connector in the Valve Cover Gasket that allows the wires to run under the VC's to operate both the injectors and glow plugs. This connector in the gasket has a tendency to burn connectors or loose connection. Wiggle the plug on the outside and see if that changes how the engine is running.

3) There is a wiring harness under the valve covers (UVC Under Valve Cover Harness as you will hear it referred). This pesky harness has a tendency to come disconnector or for the terminals to burn out. Pull the VC's and check all these connections. It is possible to locate the VC's w/a few bolts and run the truck w/o them complete bolted down for servicing to track the problem down (just bolt it all back together before you take it out on the road or you'll end up w/a mess).

If you need either the VC gaskets or the harness look at The Powerstroke Shop

Post back if you have any more questions.

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