White smoke, no power, lots of air at Schrader valve??? *new'ish motor

[Thefarmboy21]

Ok I have an 87 F-250 I just put a motor in. After all the troubles it's now got a motor from an 83-86 truck that was nice and clean and "low miles" so he said....but I needed one. Anyway after several laps around the hay field behind a tractor I finally got it fired up. It has good oil pressure (like 50's cold) but when you mash the fuel it POURS white smoke (it was dark though, could be greyish) it also seems to lack power. I drove it around the road and it rans fairly well just seemed like it was lacking and hard to take off. ALSO there's always air when I hit the Schrader valve, never a stream of fuel...there used to be a good stream when I was trying to start it by cranking, then it all just quit and I thought my lift pump went bad. But it does run just nothing but air at Schrader. Also it idles a little off...not "bad" just not smooth. At first it would idle way up spontainiously and die, then we bled more air and it would idle up and down some....the more air and it idles ok, just not smooth like it should. Sounds like it's missing. I don't know if it's air causing the smoke or a head gasket. Also could my lift pump be going bad? It's new but WAS giving me a full stream at Schrader and now just air. HELP!!!! these problems are just the motor, has some weird wiring issues too. THANKS!!

 

[GOOSE]

I would double check any lines around your lift pump, maybe one got stretched and has a crack in it. Also check your oil for diesel smell. I believe if the diaphragm breaks in your lift pump, diesel may get into your oil. I would take care of the air intrusion and then get it timed. Good luck, I'm sure others will have more insight.

 

[icanfixall]

Dragging it around to start it is telling me theres a problem. By chance did you remove the injection pump still bolted to the gear cover... If so you are not timed correctly. Post back with info on this please. We will go on from there.

 

[Thefarmboy21]

I did not remove the IP with the gear on it. I did remove the pump but was extremely careful not to disturb the gear and marked everything with a paint marker to be sure. Bad diaphram in the lift pump was my original thoughts til it started up so it's getting enough fuel to run?!?! I haven't smelled the smoke yet but that my goal for tomorrow if I can get it to start. I agree tho....it took way longer to start than I would've thought it should take to get fuel. At first I had it running off a boat tank in the bed, but it sucked two gallons dry in just a few minutes...I guess because most of it went back through the return?!?! So now it's hooked back to the stock dual fuel tanks and stock water separator (that held pressure when I blew in it) and a new Airtex fuel pump. I hate Airtex but even NAPA carries them now THANKS GUYS!!!

 

[redneckaggie]

classic fuel starvation symptoms, something is sucking air somewhere, have you changed the filter

 

[Thefarmboy21]

Yes, new filter and it was doing the same thing when it was just hooked straight to the boat tank. So the air intrusion (atleast some of it) is between the lift pump and injectors, because all the stock problematic stuff was at first bypassed. I may change the lift pump just as precaution because it acts like it's somewhat bad but maybe I'm wrong. Maybe it sprung a leak I don't know. Where would it be getting air between the lift pump and Schrader valve....or atleast causing air at the Schrader valve?

 

[Thefarmboy21]

Ok, got the rough idle taken care of....had a lose injector line at the IP. BUT still lots of air and foam at the Schrader valve. Still seems to lack the power it should have and still smoking white/grayish???

 

[lindstromjd]

Lose the water separator. Check for a stuck open injector.

 

[Thefarmboy21]

I don't have a problem doing that BUT it was sucking air when it was bypassed as well. It was just a boat tank to the lift pump and nothing in between....and it was still sucking air. As said....it had been a nice steady stream from the Schrader valve when I started this endeavor, after I ran my batteries dead a couple times cranking on it, the fuel system was losing it's prime all the time. Now everytime we start it we have to pull start it for several minutes before it builds enough fuel. Can the lift pump suck air??? There's no diesel in the oil. Would a stuck injector suck that much air? Cause it idles smooth.

 

[Hydro-idi]

Hmm have you looked at the lift pump recently? It should have a weep hole, and if it is covered in diesel fuel, it could be leaking and sucking in air, making it hard to pump fuel to the injection pump.

 

[Thefarmboy21]

I've tried....theyre not te easiest to see when in the trucks lol. Where's the weap hole?

 

[Hydro-idi]

I've tried....theyre not te easiest to see when in the trucks lol. Where's the weap hole?

It has been a while since I put a new one in my truck, but I believe it is right above the lift pump bowl.

http://s.ecrater.com/stores/233345/4ede10e161729_233345n.jpg

 

[Can30Diesel]

Another thing to consider is the lobe that drives the lift pump might be worn to the point that it doesn't really operate the pump correctly. I had that happen after my IP was starved into overheating and eventually eating itself. The crud built up in the return line check valve and caused all kinds of fun.

It might be an idea to run an electric lift pump to see if that changes anything, just bypass the mechanical one.

 

[riotwarrior]

Is it possible that when you installed the replacement lift pump, the arm got placed ON TOP of the cam not UNDER the cam?

 

[Thefarmboy21]

Well I guess it's possible but I was very careful and it's getting fuel. And it wa getting way more fuel. Then I left it sit a few days in the garage and came back and now it loses it's prime all the time and always has air!