7.3 idi injection problem

Lanithomas

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I recently swapped a used known working injection pump into my 92 7.3 idi static timed it and bled all of the lines it fired right up but ran terribly like it was getting too much fuel. Tried to retard and advance the pump to see if I could get it to run better but no luck I removed the injection line holders so I could get more movement to adjust the pump. Long story short it no longer starts. Is it common for injection lines to have holes where the holders are? Or what else could it be? I’m kind of at a loss with this truck. Tia
 

The_Josh_Bear

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How did it run before the swap? Point is, do you know the injectors and engine health are good, or do you have multiple variables beyond just the IP?

You should not have holes anywhere on the injection lines. Not it's not common, but I suppose it could be a thing. The lines are very thick walled.

If it's not running much different with a vast timing difference that points to possibly 3 other areas:
1. Fuel supply, doesn't need a lot to idle or start but if it's under vac you're toast.
2. Bad injectors
3. Bad engine internals: compression/valve/pushrod/bent rod, etc

*Pro tip: if a diesel gets "too much fuel" it just raises the RPMs. There's no throttle plate to limit air, so more fuel = more HP = more RPM. Now there is a maximum to this concept at at that point you get black smoke out the tailpipe. But until you're at wide open throttle, too much fuel isn't the issue.

*I am not a pro LOL
 

Lanithomas

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Before I swapped this injection pump I tried checking the injectors by just cracking them individually at the rpm’s it would start to miss at which was around 2000 rpm could not pin point a bad injector and was told it was most likely the ip so borrowed a known working one. The truck before would run good but would start to miss and blow white smoke at around 2000 rpm like I said but only when the truck was up to temp when it was just in normal temp range on the gauge it would drive perfectly fine without any hiccups but as soon as it got around the no in normal it would run rough.
 

ihc1470

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If it was a high pressure line you would see it. A word of caution when working around a diesel fuel system especially if you are looking for leaks. Do not run you hands around the lines! It will inject diesel under you skin, you do not want to go there. Use a piece of cardboard or a mirror. High pressure lines can be repaired if they have a hole in them by brazing the hole shut. It has been done many times in the past on many makes of engines.

I would start with the basics so you have something to work with. Check compression first, check injectors next as a leaky injector or a poor pattern can cause your issue.

How did you remove the injection pump from the engine?
 
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