White smoke and lots of air/foam at Schrader valve.

[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, but when you mash the fuel it POURS white smoke 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!!

[lindstromjd]

Get rid of your water separator (from your post over on OB). And when you got this engine, did you replace any of the injectors?

[Thefarmboy21]

Haha, well as I stated there....I was getting air intrusion when everythig was bypassed. I had it running from a boat tank straight to the lift pump and was still getting tons of air. and before that I was getting a steady stream of fuel out of the Schrader valve, then came back a few days later without touching anything and fuel system had lost all prime and ever since all I get from the Schrader is tons of air and some foamy diesel fuel, but mostly all air. It idles smooth but lacks power and smokes alot.

The injectors and IP are from the blown up motor that threw a rod....ran great when it blew...even after it had blown, but it sat for 10 years.

Could the new Airtex lift pump have went 1/2 bad and be suckin air???

[lindstromjd]

I'm not a fan of Airtex pumps. Get a Carter.

[Thefarmboy21]

I'd love to get a Carter.....but even NAPA and Car Quest carry Airtex now.

[Thefarmboy21]

Thinking about temporarily installing an inline pump in place of the water separator and seeing if I find a leak. In theory I it's sucking air while the pump is working then it should spring a leak if everything is sitting still right?

[diesel_brad]

Originally Posted by Thefarmboy21

Thinking about temporarily installing an inline pump in place of the water separator and seeing if I find a leak. In theory I it's sucking air while the pump is working then it should spring a leak if everything is sitting still right?

No. Air WILL leak in and fuel will NOT leak out

[Thefarmboy21]

Ok so I pulled all my injectors and lines today to check everything...all the injectors still had the silver neverseeze on them except one. The rear passenger side injector was coal black from the threads down?!?! Any ideas? Gonna go ahead and swap the lift pump out an install a clear fuel filter in place of the water separator to see if I'm getting air from the tanks.

[6.9er]

check all your fuel line connections. i had an air leak where the fuel lines conect to the fuel tank transfer switch and at my fuel filter and not a drop of fuel. also make sure your return line doesnt have any leaks either.

[Thefarmboy21]

Well, so far I've diagnosed two different problems.....my hunch was right and the diaphram had busted in my new lift pump, so I think that was my air intrusion problem. And as for the white smoke, 3 of my injectors tested bad and are most likely just dumping fuel into the cylinders. So now I'm in the market for new injectors....any suggestions?