91 Lumina newby problem

91 Lumina, 3.1 had an oil leak from the area of the oil pump shaft or intake to block. Due to broken heater quick connect and tabs for the valve covers broken, I removed the intake had it repaired, cleaned threads on quick connect and drilled and tapped new holes for valve cover bolts.

I put the thing back together with vacuum hoses instead of the plastic that shattered, plumbed as the diagram on the core support.

Initially the car started but ran rough, couldn't find an idle. It got worse and worse and after 2 or 3 minutes it died and will not start at all. It was backfiring through the intake. (battery had been disconnected for a week)

I jumped the A&B terminals on the diagnostic connector and the only codes received was 33 (MAP sensor high voltage or low vacuum). I have checked both the electrical connector and the vacuum line on the MAP sensor and both are okay.

Could the MAP sensor alone cause the motor to not start at all?

I have pulled the plugs and checked compression. It was suggested that I had not reinstalled the push rods correctly. #3 was lower than the others but that may have been due to not completely threaded in. #3 was 75# others were 100# to 150#. My compression tester does not have a way to tighten the fitting in the tight confines of the plug holes.

I need to get my daughter back in her ride (so I can get my car back).

Anyone have any suggestions.

Tough for us to back track all the work you did, many errors can occur during this process, recheck the plugwire/firing order, the map usually will not affect starting, 75# is way to low but again it should run.

I never pulled any spark plug wires until I did the compression check. I've got new plugs and a MAP sensor. If it doesn't start today, I'll be taking it to a mechanic because I go back on 12 hour shifts for 7 days tomorrow. And, I need to have the Ramcharger in the garage to work on it.

sounds like you have either spark plug wires crossed, or the timing of the cam to crank is out. You do realize that #1 cylinder is on the "back" or right bank of that engine configuration. How did you manage to pull the plenum & intake without pulling plug wires?

The plug wires for the 1,3 and 5 cylinders are routed in front of the manifold and under the alternator. No problem pulling the manifold.

What bothers me is that it ran initially then got worse and worse until it would not run or start again. Only code was the MAP sensor. Did a compression test. One cylinder was low (#5) but it may have been due to not getting a good seal on the compression gauge. I installed new spark plugs and a new MAP sensor. There was no change.

As soon as we can find a dolly or trailer we will take it to a mechanic that can spell GM. My only experience is basically with Mopar trucks. That's probably most of my problem...:icon16:

As soon as we can find a dolly or trailer we will take it to a mechanic that can spell GM. My only experience is basically with Mopar trucks. That's probably most of my problem...:icon16:

I'm in reverse. I've had this lumina since 1999, the 2nd gen dodge ram I've had for only 2 years. Except the air volume measurement, lack of egr, the way the two engines work is not all that different.

I'm gonna blame this one on the IAC. Was not able to learn and it killed the engine. Will it not idle or will it not run at any rpm?

Your MAP sensor error, I think it can easily be something else, as these circuits are integrated. I've gotten a MAP error without it being the map...

check all connections. there is alot hiding behind the firewall side of the engine. vacuum and electrical. especially that evil 7x CKP on the block, firewall side of the engine... can't even see it unless you are under the car.

The plug wires for the 1,3 and 5 cylinders are routed in front of the manifold and under the alternator. No problem pulling the manifold.

What bothers me is that it ran initially then got worse and worse until it would not run or start again. Only code was the MAP sensor. Did a compression test. One cylinder was low (#5) but it may have been due to not getting a good seal on the compression gauge. I installed new spark plugs and a new MAP sensor. There was no change.

As soon as we can find a dolly or trailer we will take it to a mechanic that can spell GM. My only experience is basically with Mopar trucks. That's probably most of my problem...:icon16:

But they do route over the rockerarm covers which need to come off in order to pull the intake manifold, along with the alternator, map sensor, etc. That small part on top that the throttle body attaches to is called the plenum. You must have done rocker arm cover screws only on front (left bank) of engine.