I thought I blow the head gasket. took engine apart. No evidence. Turned out to be the Air plenum. Put everything back together. Trys to start. Back fires, spits and spuders. Sounds like a timing issue. Checked wires and spert control ground. I have fuel and spark. Have not checked fuel prussure yet.
Sorry 95 SSE Bonni 3800 type K engine

You used a new upper plenum correct?

Almost sounds like the plug wires are on the wrong cylinders or you have a large vacuum leak. Was the brake booster hooked up to the back of the plenum?

I put in a new plenum in. I check the spark plugs about 6 times. I beleve there are some vacuum leaks. It looked like the booster hose connection into the plenum was loose. I assumed the o-ring would seal it. I will go throug all the vacuum connections to make sure they are sealed.

Thank you for the quick resonse.
While my car is out of commition i have to drive a 33' motor home. it is getting a little rough on the fuel bill.

What do you mean by "took the motor apart"? How far did you take it down? Did you pull the timing chain? It sounds like a timing issue

I took the heads off and replaced the head gasket. It turned out to be a hole in the plenum so it was replaced. All new gaskets. I checked every vacuum line and tie raped everything to make sure there were no leaks. No luck. As the motor was turing over I was not getting any vacuum unless it tried to fire and the needle would jump. I don't know if this is normal. The brake booster line out of the plenum didn't feel right so I added a 2nd O-ring.

Do any of the sensors have an effect on the timing while the engine is starting or is it after. I checked the throtle position and the idle sensor. but didn't get to any others.

How about the connector at the front of the ICM by the radiator. That is the spark.. if that connector is loose, unhooked or any of the above, you'll get zilcho.

I did not disconnect that one. I did give each wire a little pull to make sure there wasn't any loose ones.
I just talked to a mechanic friend and he said I should be getting 3-5 in vacuum at roll over so I am going to get a better gauge and have another look.

Put some special vacuum grease on the plenum / brake booter vacuum line and got a glimmer of hpe with it starting but it didn't. Pulled the plugs, lots of gas. dried them. Cleaned out the ctylinders with comressed air, still nothing.

Anyone have info on the O2 sensor? My book tells me if I check between terminals A-B with the engine off I should get between 350-500millivolts. I get 0 with the key off and 325 with the key on and engine not running. Would this contribute to the not starting thing?

The O2 sensor is not used for starting the car.

Cylinders are fuel-soaked, so we need to figure that out:

1. Veryify that you do actually have spark. All 6 cylinders.
2. Verify that you don't have a faulty FPR. Pull the vac line off of it and smell it.
3. Verify that yor fuel injectors are firing correctly and not drooling. Pull the rail loose, put some small cups (glass tumblers) under each one, and crank the engine a few times. Verify that they spray equal amounts of fuel, and that none of them drool aftwards.
4. Check your fuel pressure with the key on, ignition off (cycle this 3 times to prime). What is it, and how quickly does it bleed down 10 psi lower than that?