I Just bought a 1995 chevy 6.5 turbo.I smokes and shakes real bad at start-up.When I un plug the coolant sensor it quits smoking and runs great.I have changed sensors no difference.Mechanic says it may be the pump.Any one run across this before?

What color is the smoke? White or black? Cold start only? Puff or fog out the neighbors?

Edit: I just saw your other post in the other thread. Does the pump throw a code or anything? White smoke at start up may only be the glows, unless you have something else to pin down the pump.

smoke is white.mostly at start up and until it warms up fully.There is so much unburnt fuel that it fills up the crank case eventually.once coolant sensor is unplugged runs fine.There are no codes other than coolant sensor unplugged.GM say it may be the pump.If it is the pump which part of the pump is faulty?

Check all your glow plugs for .8-1.4 ohms each.

how many miles on this engine?
Plz pdate your sig so we all know what you are working on.

183000 km on engine.1995 1500 6.5 turbo.gm dealer told me no codes but I just ckecked my self and got these codes:32,33,95,51.

32, 33 are EGR stuff
95 is cylinder imbance in #5 cylinder
51 prom error

The cylinder imbalance may indicate the place to start.

Thanks for the replies!Is the prom error a serious one.Would any of these codes make the truck run the way it does,or is it the pump as the dealership says?

I'm not familiar with the prom error. My suggestion is to clear all codes. If you don't know, in OBDI diagnostic mode ( paper clip) all you have to do is step on the APP a few times and then 12 will flash, meaning all clear. Then see what comes back. EGR might indicate the vacuum pump is low/out.

cleared codes and got back 95(#5 cylynder fault).What does that mean?

#5 cylinder is in imbalance. Could be the injector possibly glowplug (at start up) or low compression causing it. Basically it's not firing.

Cylinder balance fault is the one I would worry about.

Cylinder #5 is the 3rd one from the front on the driver's side. I would pull the injector and take it somewhere to be tested. Just hope that they tell you that its hung or broken, because if they don't, then you have engine problems. It could also be a piston, ring, valve, head or head gasket problem. Does the truck overheat or lose coolant?

EGR problems will aggrivate the problem but probably not cause it.

Thanks for the replies.It does push out fluid every once in awhile.I was thinking could be a head gasket,But no air bubbles in coolant tank.It doesn't overheat either.I just bought this truck and the other owner thought anti-freeze was getting into the pan(because of high oil level and white smoke pouring out of exhaust at start up).I changed the oil(no anti freeze in the oil)unpluged the coolant sensor and runs way better.I figure oil pan was filling up because of too much fuel passing by the rings.Now with the coolant sensor un-plugged it starts and runs fine(cold or hot).It smokes a little when started cold but nothing compared to cold starts with coolant sensor pluged-in.It has me baffled!Monday I am taking it in for a warranty pump,I am just hoping this will fix it. P.S. If head gasket is gone would it push out anti freeze all the time or just intermittently?

Unplugging the coolant sensor advances to injection timing, and you say its diluting the crankcase too now, so it pretty much HAS to be a bad injector. Its hung open and squirting fuel on the piston. Replace it before it destroys the piston!!!!

RE:cylinder fault code.I just remembered something.I changed a glow plug the other day and the tip was broken off.I think it was cylinder 3 or 5.I think i better take the head off.I will check the injectors too. P.S. The dealership wants to warranty the pump,should I still go ahead with that?

Geez, if the dealership wants to give you a light bulb under warranty you don't say no!

Get it before they change their minds!

Was the glowplug tip broken or burnt off? if it was burnt then you got nothing to worry about, if it was broken then you probably want to pull the head off.

glow plug tip looks like it was chipped.Did not look melted.will let you know after I get new pump if cures the smoking problem.After warranty pump installed will pull head(s).Thanks!!