NO Spark...... TBI 88 GMC 5.7 350

[mhelms83]

OK, set your meter to Continuity, and unplug that same two wire connector at the distributor, and probe both ends where the pink wire goes, and see if your meter screams...It may sound funny, but I am hoping it doesen't!

the "2 wire connector", is that the pick-up coil wire?

 

[Jims86]

the "2 wire connector", is that the pick-up coil wire?

No, thats inside the distributor, the one we are worried about, is the on that goes from the ign module to the coil. the pink wire on that.
The power for the ingnition system, comes in through the big pink wire, and then power goes from the coil to the ignition module. it is like a branch off.

 

[HotRodPC]

I'm not up on TBI ESC as much as Non TBI ESC, so I'd hate to suggest it if different, but on the older ESC, you could snip wire A (Black) and C (Green) on the dizzy plug twist the 2 together and this bypasses the ESC module. Apparently TBI ESC has 5 wires instead of 4, and I assume that extra wire is the one that goes to the injectors switch according to your diagram. Also in your diagram is shows C as going back to the ECM, so it makes me wonder if he did do an A and C wire twist if it would bypass both ESC module and ECM and then start. If that works, then the problem is narrowed down to ESC module or ECM. But I don't know that wiring. You'd have to think about that and see if it's possible.

 

[Jims86]

* no power at the harness when its unplugged. but i think that smaller gauge wire brings power from the coil to the ign. mod. am i right?

Yes, and power for the coil, comes through the large pink wire from the key.

HR, that would work on a CCC setup, but not on TBI where it relies on a reference signal to run the injectors. Of the 3 wires going to the ECM from the ign mod, only one effects the Ignition, and thats the EST wire. the other two are for fuel injectors and tach info for the ECM.

 

[mhelms83]

No, thats inside the distributor, the one we are worried about, is the on that goes from the ign module to the coil. the pink wire on that.
The power for the ingnition system, comes in through the big pink wire, and then power goes from the coil to the ignition module. it is like a branch off.

yes the smaller pink wire from the coil to the ign. mod. has power.

 

[Jims86]

yes the smaller pink wire from the coil to the ign. mod. has power.

Ok, now do a continuity test on the white wire in that same harness that goes from the distributor to the coil. this is the wire that fires the coil.
Next thing to check, is dist ground.

 

[mhelms83]

Ok, now do a continuity test on the white wire in that same harness that goes from the distributor to the coil. this is the wire that fires the coil.
Next thing to check, is dist ground.

im not sure on how to do a continuity test using my multimeter. but the white wire from the black harness to the ign mod has power at the ign mod plug

 

[Jims86]

im not sure on how to do a continuity test using my multimeter. but the white wire from the black harness to the ign mod has power at the ign mod plug

there is a setting on it that emits a beep or buzz when you touch the probes together. thats the one you use to find a broken wire.

 

[mhelms83]

there is a setting on it that emits a beep or buzz when you touch the probes together. thats the one you use to find a broken wire.

i used i different reader and it has a setting where it beeps continuously and says "short", when the pos. probe is connected to the white terminal and the neg. probe to a ground it reads "open". am i headed in the right direction?

 

[Jims86]

i used i different reader and it has a setting where it beeps continuously and says "short", when the pos. probe is connected to the white terminal and the neg. probe to a ground it reads "open". am i headed in the right direction?

no, you want a prob on each end of the wire you are testing. one probe on the pin for the white wire at the coil end, and the other probe in the pin for the white wire on the distributor end.

 

[mhelms83]

no, you want a prob on each end of the wire you are testing. one probe on the pin for the white wire at the coil end, and the other probe in the pin for the white wire on the distributor end.

ok it read "short". but again im not 100% sure im using the right setting

 

[Jims86]

Short means there is continuity, the wire is not broken, a broken wire would say open. do you have a set of jumper cables that you can clamp one end on the distributor, and the other to the bolt on the negative battery terminal, then try to start it? Plug the wires back in between the coil and dist....dont want to forget.

 

[mhelms83]

Short means there is continuity, the wire is not broken, a broken wire would say open. do you have a set of jumper cables that you can clamp one end on the distributor, and the other to the bolt on the negative battery terminal, then try to start it? Plug the wires back in between the coil and dist....dont want to forget.

im sure i sound ignorant, but where on the distributor should i clamp the jumper cables?

 

[Jims86]

im sure i sound ignorant, but where on the distributor should i clamp the jumper cables?

No, the question that you DONT ask,,is the stupid one...you are learning.
If you can, clamp it to the base or stem of the distributor, under the cap.

 

[mhelms83]

No, the question that you DONT ask,,is the stupid one...you are learning.
If you can, clamp it to the base or stem of the distributor, under the cap.

ok, hang tight.