GM TBI swap - I'm stumped

[elskeptico]

Well I changed the wiring per your diagram, and it solved my run-on problem (obviously), but otherwise nothing changed.

Started it up, ran pretty rough, drove it around the block (felt pretty good), back in the driveway and it died.

At this point I’m spittin in the wind but thinking maybe the ignition module is bad. Tested resistance on the pickup coil and it’s about 650, so no obvious trouble there.

[elskeptico]

Does look like weak spark? It's the only thing I can think of that could cause this.

[wiley-moeracing]

Looks good, blue would be weak, but then again my vision is not what it used to be!

[elskeptico]

Looks good, blue would be weak, but then again my vision is not what it used to be!

Hmm...I thought blue or white is strong, red or yellow is weak.

Anyway, I swapped to a different coil (older TFI) and things are just as wacky.

I've set the dizzy to ZERO. I tried putting a timing light on it while it's cranking and the mark doesn't even show up, I can't see it anywhere on the scale (which only shows advanced), so my thinking is the ECU/ICM is retarding the timing so much that the mark on the crank is showing up behind all that stuff.

[babywag]

Did you unplug the timing set wire connector?

[elskeptico]

Did you unplug the timing set wire connector?

Originally, no. But I just gave that a shot and no change. Still can’t see the mark on the crank at all while cranking

[babywag]

That would suggest timing is way off...
I mean I can see mine when it's way advanced @idle
I painted the groove on the balancer with some nice bright yellow paint.

[elskeptico]

If it were way advanced I’d be able to see it, but since it’s retarding it so much I can’t see the mark.

I know I’ve got the dizzy set right to TDC, and I know it’s the compression stroke because I did the test with a vac/comp gauge on cylinder #1.

Something in the ECU and/or ICM is retarding the timing by a lot for some reason. Could this be related to the dizzy star wheel being slightly out of phase? I know folks don’t usually have an issue with that...

[elskeptico]

Is there something like the EGR connection that I’m supposed to ground or otherwise disable if I’m not using it?

[babywag]

I would focus on timing...if you're confident in distributor install and you believe it is retarded adjust it.
with timing set wire disconnected the ecm doesn't alter timing

[elskeptico]

I would focus on timing...if you're confident in distributor install and you believe it is retarded adjust it.
with timing set wire disconnected the ecm doesn't alter timing

So this is the only way I can get it close to starting, and if I flutter the throttle and hold it open a bit it will run really rough. At TDC the rotor is so far past the #1 cylinder post that it appears closer to the #8 post. When I put a timing light on it while cranking, the mark shows up real close to TDC.

[babywag]

Same as normal setup...
Align rotor with your #1 on cap when installing distributor.
#1 can be any post on cap provided plug wires installed to match that position.

If proper alignment cannot be obtained raise distributor move it tooth drop it back in?

Distributor a tooth off? Or plug wires 1 position off?

[elskeptico]

Align rotor with your #1 on cap when installing distributor.

What I mean is if I do this (align rotor with #1) it won't start and timing will look super retarded while cranking.

The way it's pictured is the only way it will get close to starting.

[babywag]

In that pic, the engine is @ #1 TDC?

How is the pickup/advance plate locked down?

[elskeptico]

In that pic, the engine is @ #1 TDC?

How is the pickup/advance plate locked down?

Yup, it’s at #1 TDC.

Pickup is attached to the vac advance thing, no vac attached. The part with the springs/weights is welded.