94 Blazer- Bog Down and stall when cold

[FutureFire]

My 94 Blazer s10 is a v6 Vortec 4x4~


Issue:
When the engine is cold there is a vibration coming from firewall top area of engine. The engine will periodically bog down/ then the CPU will dump fuel into the engine and the RPM's go up for awhile then it bogs down again. Sometimes it will stall before cpu can dump fuel on it, the issue is getting worse and worse with stalls becoming more frequent. I can avoid stall by hitting accelarator. Once all the way warm and driven on normal honey do errands for the day it runs perfectly, vibration even gone. No idiot lights yet;

Current troubleshooting done
I was almost certain that the vibration was cap and rotor. I could feel vibaration strongest when I put hand on cap while idle. Replaced cap and rotor to no avail. Will be replacing wires and plugs this week. However I am by no means a rich man and diagnosing this problem by replacing ignition system a piece at a time then moving onto fuel delivery and air control systems will break a fool.

[BlazerLT]

Check your CPI injector by removing the top Vortec cover plate, remove the round IMTV valve under it noting its orientation for reinstallation and then take a flashlight and shine it down into the hole and look for pools of fuel, the strong smell of gas and washed spots that will be a golden color.

[FutureFire]

Originally Posted by BlazerLT

Check your CPI injector by removing the top Vortec cover plate, remove the round IMTV valve under it noting its orientation for reinstallation and then take a flashlight and shine it down into the hole and look for pools of fuel, the strong smell of gas and washed spots that will be a golden color.

Removed IMTV valve and checked CPI injector for leaks/additional wear and all looked normal. No strong smell of gas. Going to hook up OBD1 Scanner and see if we can see anything with the sensors; We also are going to check fuel pressure; Still looking for suggestions.

[BlazerLT]

Was there any golden washed spots>

Pools of fuel?

[FutureFire]

No.

[BlazerLT]

Originally Posted by FutureFire

No.

So it was perfectly black down there with no discoloration at all?

[FutureFire]

Originally Posted by BlazerLT

So it was perfectly black down there with no discoloration at all?

It was almost perfectly black, there were no clean spots or discoloration. There did not appear to be any leaks at all. Any other ideas?

[BlazerLT]

Check fuel pressure.

[FutureFire]

It was a bad distributor. I got a new one and put it in. Do you have any idea what the timing should be set to, and if there in any wiring that must be jumped or disconected while setting the timing? Or where the timing mark is? I am too tired for this. Thanks for your help.

[BlazerLT]

Originally Posted by FutureFire

It was a bad distributor. I got a new one and put it in. Do you have any idea what the timing should be set to, and if there in any wiring that must be jumped or disconected while setting the timing? Or where the timing mark is? I am too tired for this. Thanks for your help.

Remove the timing wire from the PCM, set to zero with a timing gun, reconnect wire.

[FutureFire]

Do you know where the timing wire is that I must disconect?

[BlazerLT]

under the glove box.