biffidun Posted September 27, 2011 Share Posted September 27, 2011 (edited) I can't seem to identify the injection pump on my truck. (I will try to get a picture ASAP). Basically I know it is a Bosch and it has an external puff limiter air piston. The governor seems to be located at the front of the pump (close to front of engine).I have cleaned and removed all the puff limiter components (I replaced the remote air valve) and all seem to work, but I am still getting loads of smoke. I put a boost gauge in the cab and I can see 15psi boost (not a great gauge so it could be more) BUT the truck has to be under load (driving to see that boost) to get that. Goosing at idle produces no boost. I still get smoke even when boost registers while driving. I get quite a bit when I shift and then it tails off, but never goes away.The engine is marked as a 3B family model EN? 576. It starts and idles nicely with little to no blow by.I would like to dial out the fuel rail, but I don't know what to adjust on this pump for that. I would assume I have to remove a plate at the back, but which screw do I turn to back off fuel delivery?Any thoughts would be appreciated. Edited September 27, 2011 by biffidun Quote Link to comment https://www.bigmacktrucks.com/topic/20787-injection-pump-over-fueling/ Share on other sites More sharing options...
Rob Posted September 27, 2011 Share Posted September 27, 2011 One of the most common causes of this symptom is a busted intercooler, leaking interconnecting hoses, and/or restricted air filters. After verifying you have a good air filter element, have someone hold the idle at or above 1500rpm while you spray the intercooler with soapy water and look for bubbles.I'm making the assumption the problem has started recently and not after someone has "monkey'd" around with the governor and/or injection calibration. I use the term monkey'd around as to not arouse randyp.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/20787-injection-pump-over-fueling/#findComment-87064 Share on other sites More sharing options...
Lmackattack Posted September 28, 2011 Share Posted September 28, 2011 I think your starving for air..not over fueling..what truck is this engine in..the 675/676 made around 23 psi of boost. Quote Link to comment https://www.bigmacktrucks.com/topic/20787-injection-pump-over-fueling/#findComment-87069 Share on other sites More sharing options...
biffidun Posted September 28, 2011 Author Share Posted September 28, 2011 Well, this a 237HP 3B family engine. There is no intercooler on it. I opened the back (top) of the injection pump and there was a mechanism in there that appeared to alter fuel rail travel. A couple of the screws had been fudged up, so someone has been monkeying .... I dialed it back a bit and things seem better. I do think the turbo is a bit lazy though, so.... well I don't feel like spending $1000+ for a new turbo so let it be for now. I'll get a more accurate gauge for the turbo and hook up the pyrometer.Regards. Quote Link to comment https://www.bigmacktrucks.com/topic/20787-injection-pump-over-fueling/#findComment-87096 Share on other sites More sharing options...
Rob Posted September 28, 2011 Share Posted September 28, 2011 Well, this a 237HP 3B family engine. There is no intercooler on it. I opened the back (top) of the injection pump and there was a mechanism in there that appeared to alter fuel rail travel. A couple of the screws had been fudged up, so someone has been monkeying .... I dialed it back a bit and things seem better. I do think the turbo is a bit lazy though, so.... well I don't feel like spending $1000+ for a new turbo so let it be for now. I'll get a more accurate gauge for the turbo and hook up the pyrometer.Regards.Be extremely careful using that word "monkeying" on this website. The use of that word makes randyp want to squeeze his banana and do all kinds of weird shit.Glad you got your problem addressed but you best be careful adjusting on an injection pump with no experience. Very easy to destroy an engine and a $1000.00 turbocharger, (if defective) will be a minor cost in the overall picture.I would recommend you take the truck to a diesel shop and have it properly tuned to specifications. That old 237 engine is virtually indestructible if taken care of. Boosting fuel delivery 10% over factory calibration will not be detrimental to the engines life, (short term) but the engine does need to be sound to start with. 237's never had intercooling and there are Gillions out theres still performing their missions respectibly. That engine was kinda like trying to tear up a steel ball in a padded room with your bare hands. No wait, that is my life.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/20787-injection-pump-over-fueling/#findComment-87098 Share on other sites More sharing options...
MACKS Posted September 28, 2011 Share Posted September 28, 2011 Also possible that the puff-limiter needs to be adjusted or maybe its not working at all,try a snap test first with parking brake on and then off,should be a lot less smoke with the brake off. Quote Link to comment https://www.bigmacktrucks.com/topic/20787-injection-pump-over-fueling/#findComment-87103 Share on other sites More sharing options...
miro Posted September 28, 2011 Share Posted September 28, 2011 The old 237's with a fabricated intake manifold also had probles with the manifold splitting along the seam Quote Link to comment https://www.bigmacktrucks.com/topic/20787-injection-pump-over-fueling/#findComment-87107 Share on other sites More sharing options...
biffidun Posted September 29, 2011 Author Share Posted September 29, 2011 (edited) Thanks for all the replies. The truck is running great now. I don't get much smoke (parking brake off) and the aneroid valve seems to be doing its thing as you can feel the power build as the valve kicks in with the turbo.Here is a picture of the old beast. It actually had the cab replaced from a mid 80's truck. Cement truck, so no rust. Trouble is the guys that swapped the cab were hacks and the wiring was a mess. I have most of it fixed now. I just have to tie up anything loose and weld two cracks in the rear cross members. Not big cracks, but it needs to be done properly.Now if I could just get the reverse lights working...BTW it is a 1976 Edited September 29, 2011 by biffidun Quote Link to comment https://www.bigmacktrucks.com/topic/20787-injection-pump-over-fueling/#findComment-87166 Share on other sites More sharing options...
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