6.5 blowing smoke after rebuild

[jcwright]

OK, so here goes the story. Bought a 1996 c1500 burban. Had a slight engine noise, border line knock. 215k on clock. Tear down the top end and find carburized oil on 6 and 8. Remove engine and replace the following: Pistons (bored .040 over) new heads, new crank, new lifters, new camshaft, reman GM injection pump, new turbo, New GM injectors and glow plugs, ARP studs. Reassemble engine with all good specs as per service manual. Piston clearance spot on, ring end gaps on. So I decided to install a .010 head gasket to lower compression a bit. Well since then engine starts and runs rough smells like raw fuel for 2 or 3 mins and chooches like a steam engine. After engine cylinder temps come up miss goes away and runs ok. Seems down on power. Do compression test 250psi to 300psi. WHAT THE HELL? My question did I screw myself with the plus .010 head gasket? Help please......:confused:

[JeepSJ]

Those head gaskets don't affect compression enough for you to notice any power difference. Where did you source the "GM" injectors? Been stories of cheap Chinese crap coming in GM packaging. What is your pump timing?

[sctrailrider]

Did you go through the process of timing the motor? If not that needs to be done, and you will need the correct scanner to do it, a GMTD I think.. With a electronic IP you can't just replace it and expect it to be right..

[jcwright]

The injectors are AC, came from my supplier and have bosch stamped on body. The TDC offset is -1.23 and the timing is at 3.5 when in scanner timing mode. Also verified no air in system with clear lines and double checked the injector line routing. Also has new fuel filter housing and lift pump which are GM. I had the TDC at -.88 and smoked worse. Before Tear down the thing ran good with no smoke and plenty of power. I even installed my old injectors and same thing

[jcwright]

:) After pulling my hair out, Found 2 leaks in fuel system. 1 leak at the T on injector return to IP, line was craked at weld. The other was a pin hole in the drain line from the filter housing. Also the compression gauge was a POS. No more smoke on start up!!!!
Set TDC offset to -.035 as well

[Warren96]

I sometimes check my fuel system integrity, by loosening and tightening the fuel cap. This checks not only the supply line, but the return as well.If you hear a hiss, when you loosen the cap, your "Golden". But now that you fixed the leak, you may want to get back to resetting the timing. Mine was running on the hot side on warm days at a setting as low as you set your's. Take a look at where mine is at the bottom of this message. A more negative setting will not only run cooler, it will also help you get better fuel mileage, and POWER !!!!!!! Just turn the top of the pump a hair at a time towards the drivers side to advance the setting, towards the passengers to retard.Then take it for a spin around the block. If it sets a code go back one hair. As others have said "It's shocking how close you can get to it by ear." The computer will set a code if you advance too far.

[ronniejoe]

You'll see improved response and performance if you set the TDC Offset to -1.94. I saw +4 hp and +9 lb-ft on Kennedy's chassis dyno when changing from factory spec to -1.94 TDC Offset. The gain is real.