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Hi Guys - R & R'd my mechanical pump on '93 IDI 7.3. She's running with plenty of fuel pressure at the top filter but smokin now lots Any suggestions, is it unburnt fuel due to air in the system? There was no smoke prior to pulling the old pump, I need to prove my wife wrong - ie buying a diesel was not a bad choice .
Well, I just idled it for a few minutes, it seemed to be missing a bit but no knocks or nasty sounds from the engine. The smoke was pretty much continuous tho. Maybe a bit of driving will clear it up - I hope.
I hope you followed the lift pump installation instructions to a T ... Serious damage can occur if incorrectly done.
Did you bleed the air out after installing ... Not that it matters now if you got it running.
If it's air in the system and you got it running it should clear up within minutes, if not something else happened and more info is needed.
I followed the instructions as clearly as I could and the pump went on nice and flat with no resistance really. I can understand that damage could occur because it would contaminate the case in no time with two bit parts from the pump actuator. Also talked to a buddy of mine who is well versed on these engines (and diesels in general) and he figured I had it on correctly. Just out of curiousity, if a person was to turn the engine through by hand in the wrong direction a time or two (prior to start up) would that screw things up Also, is there a timing issue if the engine is cranked with the fan belt off??
Thanks for that, it could be sucking some air prelift pump as the rubber line at the inlet looked a little crappy, would that cause grey/white smoke. It is also idling a bit rough but only ran it for maybe 3 minutes.
your just seeing the white smoke at startup now,because you were not looking for it when you ran the truck.
just run her,and see if the smokes disappears.
the smoke your seeing at cold startup is likely normal.it should go away in a few minutes.
i think your just nervous because you just bought the truck?
Thanks for that, it could be sucking some air prelift pump as the rubber line at the inlet looked a little crappy, would that cause grey/white smoke. It is also idling a bit rough but only ran it for maybe 3 minutes.
Run it longer than that, even drive it down the road and back.
You need to get it up to operating temp.
Yes, Air could cause the rough idle and smoke, It will also Surge.
Surge = RPM goes up and down when holding throttle steady.
Good day, thanks for the input - yes, I am sure the smoke is due to just not warmed up as well as the surging as you said Festus. I was a bit freakydeaky about not having the lift pump on properly and reading more in that is there. That being said, still havent had her out for a run but am sure it should be ok..
I haven't done it (installed one wrong) so I don't know for sure, But I got a good feeling if the lift pump was installed incorrectly you would already be crying in the broken parts!
It would of been noisy and obvious.
Paranoia can save one money, it can also drive one nuts!
She seems to be running pretty good now, no more smoke so just needed a warm up and get some air out. Thanks for your help, my next issue is its still dredging up oil in the rad from a year ago almost when the oil cooler went for a crap. I don't think the guys ever flushed things properly. Oh well..