No power unless timing is way advanced

91 Mighty Max 4x4
6g72 engine

Replaced Cylinder heads (used ones)
New timing belt

When timed properly (at 0*) it feels extremely sluggish. With the timing advanced 30 degrees, it idles at 1,000 rpm, and has normal power.

Ive verified that the timing belt has not slipped, everything lines up to TDC (did a piston stop test to verify), distributor lines up to cyl #1.

Ive checked the belt and positions 3 times to make absolute sure.

I'm pulling my hair out. Do you guys have any opinions?

Thanks.

How did you align the cam?
Many people go off the flat of the head. That is NOT correct.
If it needs to have LOTS of advance your off 1 tooth and it will rev slow with no power.
See this one for distributor grounding
http://www.mightyram50.net/vbulletin...th-ECM-control

See the picture in here.
http://www.mightyram50.net/vbulletin/showthread.php/2258-G63B-2-0L-Cam-Timing-Mark

Quote:

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Originally Posted by camoit

How did you align the cam?
Many people go off the flat of the head. That is NOT correct.
If it needs to have LOTS of advance your off 1 tooth and it will rev slow with no power.
See this one for distributor grounding
http://www.mightyram50.net/vbulletin/showthread.php/5368-How-to-set-the-timing-on-your-2nd-gen-Mighty-Max-with-ECM-control



See the picture in here.
http://www.mightyram50.net/vbulletin...am-Timing-Mark

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Phuzy is running a 3.0 V6. That being said - have you ground the ECM to trip it into diagnostic/tune mode? It won't accept a new tune until the ECM has been set. If this is the issue and it solves the tune problem, would you be prepared to try an experiment for me? Use this method to tune your truck and report back with your findings - http://www.mightyram50.net/vbulletin...ll=1#post56600

I have used this on OBD I ECM's and it made a noticeable difference on 4 cylinders, but I can't see any reason why the same (if not greater) gains will be made on the V6 lump.