Smoke at Idle, Not under Load...

[4x4 SD22]

Hi guys, I'm a long time fan first time user.
So I've been into these SD diesels for a bit now and I've done a few transplants and stuff. So far all has gone well, except for my newest edition; 85 Nissan truck standard cab.
Soon after I completed the transplant I started driving it and as usual it smoked for the first little bit (first 25 miles or so), but after it warmed up no problems. I ran it good and hard put about 100 miles on it. It still smokes! but only at idle not under load, and its an un-burnt fuel smoke. I know the engine is good, the doner truck ran great with only 160k (it had a bad trans, bad body, ext).
I did some investigating and at idle the problems always comes back, it misses in cylinder 1&4. I'm thinking its due to Air in the Lines cuz I can crack them while its running and it blows bubbles for a second. The system has been bleed and bleed, all the lines are new, it's always hard to start (I've never used starting fluid).
I'm fairly capable, and this is not my first diesel by far, but I'm baffled by this one...

[waynosworld]

Have you checked your valve clearances?
Does it have an inline injection pump, or is a VE type?

[asavage]

If you suspect air in the lines, use the temporary clear vinyl fuel supply line method to ascertain whether it's sucking air.

If it does this when hot, you can rule out the usual culprit: problems with the glow plug system, which give cold miss and white smoke, a very common SD22 problem.

Checking the valve clearances isn't a bad idea in general, but they really shouldn't be changing much, and esp. not closing down. You may want to perform a compression test to rule out cylinder imbalance.

I think your guess about air getting to the IP is a good one.

[big0078]

try a new leather in the injector
pump

[asavage]

If it's got an Inline IP, and the leather governor diaphragm is leaking, you'll get black smoke at idle, not white.

[larrynsr]

check that the throttle body hoses are not kinked going to the injection pump. too much fuel not enough air causes black smoke.