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overfueling?


pmolitor
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my 79 RS with an endt676 seems to be blowing more black smoke than it used to. Doesn't seem to have the power it used to. Doesn't use any oil and not much blow by. just a lot of smoke under hard pulls. I replaced all the injectors last fall. could the pump need overhauled or is there something else I should look for?

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Random thought.

If the air relay on the intake manifold for the puff limiter is screwed up it could be sending a false signal to the injector pump. It could explain the black smoke.

in a pull under throttle the puff limiter is all the way off, if it was messed up it wouldnt run well but there wouldnt be any excess fuel smoke either. If the air filter was stopped up and the fuel filters were good it would get extra smoke, if the fuel filters were clogged it would smoke less, if the smoke limiter wasnt moving from the idle position it would smoke less, if the lift pump were going out it would smoke less, if the injection pump was taking a dump it may smoke more, it would definitely run worse, just out of curiosity you havent gotten it real hot have you? If you inadvertantly got the cylinder temp too high on a long pull with a load as I remember you saying you had isues with in the past the tips on the nozzles may be melted and just drizzling fuel instead of atomizing it, thus making it smoke more and run worse, actually thats the first place Id check after the obvious external stuff on a Mechanical engine.

"Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin

"If your gonna be STUPID, you gotta be TOUGH"

"You cant always get what you want, but if you try sometimes you get what you need"

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Basically, if the puff limiter is not working properly you will either have no smoke and low power or allot of smoke and slightly more power in the low rpm's. Since you have excessive smoke and feel like it has less power, I would take a good look at both inlet and outlet side of the turbo. Make sure there are no excessive leaks on the pressure side after the turbo.

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I don't think this one has been hot.... my memory isn't all that good anymore:-). I lost my pyro early this summer. new one will be in in the morning.

I did figure out the 90 ch with the em6l problem. the fuel filter housings were full of what looked like rags.... cut all my power! cleaned them out on the side of the road one day sfter it died on me. I think that was the one that you remember 84duperdog.

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Basically, if the puff limiter is not working properly you will either have no smoke and low power or allot of smoke and slightly more power in the low rpm's. Since you have excessive smoke and feel like it has less power, I would take a good look at both inlet and outlet side of the turbo. Make sure there are no excessive leaks on the pressure side after the turbo.

How about the gaskets on the intercooler core, the clamps on or the small hose going to the tip turbine fan, the clamps or the hose between the intercooler manifold

and rear intake manifold?

Ron

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Also check and see if the termocoupler for the pyrometer is in the manifold. If so and your pyrometer has went bad it could have drop the thermocoupler inside taking the turbo wheel out with it.I have seen it a few times years ago when they installed in manifold. I want them in the exhaust behind the turbo.

glenn akers

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Go to a Borg Warner turbo dealer for a turbo it'll be half price and its a better turbo, I can cross reference your p/n to a Borg number if you have it off your turbo.

"Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin

"If your gonna be STUPID, you gotta be TOUGH"

"You cant always get what you want, but if you try sometimes you get what you need"

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How much boost are you making with the new turbo? Did you idle the truck up to about 1000rpm and spray soapy water all over all the charge air pipes and intercooler to make sure it wasn't leaking? How high are the egt's?

"Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin

"If your gonna be STUPID, you gotta be TOUGH"

"You cant always get what you want, but if you try sometimes you get what you need"

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With egt that's high you have too much fuel and not enough air or some slobbering injector nozzles that aren't atomizing your fuel. One things for sure you'll burn that sucker down if you drive it like that long, I try to keep my egt around 900-1000 on long pulls loaded heavy normal driving light they shouldn't top 700-800 depending on.how hot your pump/injectors are. Check to make sure your not losing your charge air and if not, remove the cold (intake manifold) side charge air pipe and see what kind of flow your getting thru the cooler, it would be odd but possible for a blockage or internal damage to restrict the charge air flow thru the cooler.

"Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin

"If your gonna be STUPID, you gotta be TOUGH"

"You cant always get what you want, but if you try sometimes you get what you need"

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Your still running it with 1200 degree egt's? well did you check the whole charge air system for leaks, you should see bubbles if you spray it down, have you thought about pulling your injector nozzles? Im still thinking if you dont have any charge air leaks its getting too hot and has too much fuel smoke, that combined with low power makes me want to pull the nozzles and look for one or more to be melted.

"Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin

"If your gonna be STUPID, you gotta be TOUGH"

"You cant always get what you want, but if you try sometimes you get what you need"

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