Rebuilding TBI Injectors

[dsiekman]

My port engine has run a little rough since I bought the boat a couple years ago. By "rough" I mean it physically vibrates a little and seems to require a little more throttle to be sync'd up with the stbd engine while underway. It also just doesn't sound as smooth as the stbd. We've tried all the basics but no luck - fuel filter, plugs, cap, wires, etc. Last fall when I had the boat winterized the mechanic said that when he fogged the engine it smoothed out considerably which to him meant it was running lean. He said thinks one of the injectors may be partially clogged and suggested either buying new ones or having them rebuilt/cleaned by one of the many online shops that will do that. Has anybody tried this? Did it make a difference? I like the idea of rebuilding/cleaning over new due to the cost difference - about $50 vs. $250.

The engine is a 2000 VP 5.0Gi. I believe it is the PEFS but will check when I go back down this afternoon.

 

[Don S]

Re: Rebuilding TBI Injectors

Well, it would make a difference if the running rough was caused by a partially plugged injector. So just because it might fix someone elses boat doesn't mean it will fix yours.
I have sent many injectors out for rebuild and cleaning and they always worked like new.

Have you done any troubleshooting for the rough running? Compression test, vacuum test on the engine, fuel pressure tests etc. spark test on all wires. That fogging oil makes any engine run different, and it may not be because of a lean condition.
Not sure what "We've tried all the basics but no luck" includes.

 

[dsiekman]

Re: Rebuilding TBI Injectors

Thanks, Don. Sorry, I should have said we've replaced (most) all of the basics. The purchase got a little ugly when it became obvious that the marina who was brokering the deal had not completed all of the work they were contracted to do and claimed was done. Rather than rely on their word, I replaced the fuel filter, plug wires, and dist. cap. I was reminded when I was at the boat today installing new plugs that we did not do the plugs although I don't remember why. That leads to my next question...

When I pulled the old plugs they were gapped at about .035. The VP manual I found on line last night had the recommended gap for a Champion RS12YC at 1.1MM or about .043. Any chance that has something to do with the rough condition? Also, could improperly gapped plugs damage the engine?

Also, I was incorrect. It is a PWTR, not a PEFS. Just curious, what's the difference?

 

[BreakOutAnotherThousand]

Re: Rebuilding TBI Injectors

PWTR is a 1998-1999 motor
PEFS is a 1999-2000 motor


Injectors, especially TBI injectors, can not be rebuilt only cleaned.
I have used witchhunter for both my boat, and trucks injector cleaning, they do a great job.

 

[dsiekman]

Re: Rebuilding TBI Injectors

Thanks! I looked at Witchhunter online. Haven't done anything about it yet.