83 K5 Blazer

[83k5blazer]

I just finished converting my SBC 350 carb'd over to TBI 7747. It starts and runs but stutters when gas is initially pressed. (Problem#1) I've set the timing (removing the connector) and set to zero but it doesn't advance when connector is plugged in. When i give it gas the timing retards a few degrees under zero.
(#2) I also have a loud hissing sound like a vacuum leak but i found that the sound is coming from the top of throttle body, the hole that the IAC uses. When i stick a rag into the sound goes away and the idle goes down to normal.

Ive used the donor trucks wiring harness, sensors, TBI, and computer. I haven't installed a Wide band O2, Knock sensor or Vehicle Speed Sensor yet (waiting on money). I do have heads, cam intake manifold, and long tube headers installed. Heads I-200/E-74, Cam 206/214 @.050. I've already purchased a Burn 2, ALDL cable, Tuner Pro, and modified the ECM to accept the 27SF512 chip. (#3)I'm just at a loss when trying to figure out what i need to adjust. I basically took the ASDW $42-5.7-Manual bin and uploaded onto new chip and turned the EGR patch on. I've just been reading and trying to learn but i need the truck for driving to work in the snow. Help with any of these problems would be appreciated.

miggy

[Fast355]

You have to shut off the engine in some years before the ECM will command timing advance again.

[83k5blazer]

yeah i shut it off when i plugged and unplugged i was afraid to shocking the system. I think some how the EST is bad or went out. i have one on order.

[83k5blazer]

So i changed one of the patches BPW and Spark to enabled. Got rid of the stutter and timing issue. I just have to keep reading and learning to read the log.