I recently had my 98.5 vp44 engine rebuilt due to a melted piston after the truck was stolen. Ever since the rebuild I have had a smoke issue. Under light throttle, the truck smokes black. Running empty down the freeway the truck constantly smokes black. Smoke is worse pulling a trailer. Truck starts great, idles clean. No crank pressure. Oil level does not increase or decrease. No codes showing.

BUILD:
-Block was sent to a machine shop, bored 0.020” and decked 0.010”. Running a thicker head gasket to maintain factory compression ratio.
-D&J stage 1 head w/ orings 
-Hamilton 178/208 cam w/103lb valve springs. 
-New vp44
-7x0.010 Sac injectors
-62/68/12 turbo
-FASS 165
-Edge J w/ A

Trouble shooting:
-Tested for boost leaks
-New MAP sensor
-Removed the edge 
-Sent the injectors for testing 
-Tryed another new VP
-Compression tested (445-455psi) on all cylinders 
-Ecm was tested
-Installed stock injectors and same amount of smoke while driving

-checked ECM grounds (pin 30/49)

Cruising at 70mph in OD the truck runs about 1800rpm, 7psi and 850f with smoke
WOT seems to clear up to a heavy haze. 
38-40psi of boost and 1250f. 

Before the rebuild I ran a set of 7x0.0095 SAC with the same 62/68/12 and only smoked if you really put your foot into it. 

Thanks in advance

Edited October 4, 20213 yr by LTL Diesel

The only thing I think you might check is the key in the VP44 pump shaft is it installed correctly with arrow towards the pump. Make sure the number matches the number on the case. Typically with timing slightly retarded it will smoke. 

 

Like myself I'm right about 19 to 20 degrees on the Quadzilla. This is a limitation of the Edge tuner. Running 150 HP injectors with little to zero smoke.

 

Everything else seems to check out good.

Thanks for the reply. 
I recently had the front timing cover off to inspect the pump key and confirm it was seated correctly. Also double checked the timing with the crank, cam and pump. Everything looked good and now I’m at a stand still. Don’t know where to look next. 

Check for air restriction. Start with air filter and intake then intercooler, grid heaters and manifold. Sometimes during rebuilds rags get shoved in places to keep things out and get left behind.

I agree that it does happen. I checked again today for a restriction in the intake system, (filter, turbo, intercooler, grid heater, intake plenum) Didn’t find anything unfortunately.

 

If there was a major restriction before the map sensor, wouldn’t it read lower than normal? 
Boost pressure seems to be right on mark at 6-7 psi cruising empty and 38 psi WOT. With this I am thinking it is fuel related. With stock injectors I had the same smoke issues. Change the vp out, also didn’t change anything. I am thinking maybe something computer related may still be the issue. Could the fuelling curve be out within the ecm?

Did you wipe the cam out? Watch the rocker arms while it's running look for any low lifting ones. And try a temporary mechanical boost gauge all those tuners fool with the boost. I found walnuts in intake ports on a small block Chevy before lol.

I will pull the valve cover next and watch the rockers as it runs. 
I have a mechanical boost gauge reading from the plenum and it reads the same as the MAP sensor through the edge monitor. 
Thanks 👍

All the rockers move in sync, can assume cam is good. 
 

Talked to the guys that reflashed/tested the ECM and they said everything in the test simulation tested good. 
 

Another thought.. Before the rebuild, the engine was ran to extreme temperatures. Data log showed engine coolant temperature peaking at 291f. If a wire was to be broken either during the heat or in the rebuild process, which wire could cause the fuelling curve to be out?

Found a working ecm out of another 98 24v auto. Put it in the truck and ran the same as before.. smokey

 

Here is a driving video of the smoke if anyone has any ideas.

Unplug any adapters or "y" on the map sensor and plug it straight into the factory connector.  Disconnect any fuel tap wire or stealth unit on the vp also.

Unfortunately I already tried that. I unplugged the boost fooler y-plug from the map sensor and ran the factory wiring without change. Also tried running with the map sensor unplugged and still no luck. Have not tapped the injection pump yet.