1994 SE with 184,000 well cared for miles. 80% of the time it starts fine but the other 20% with absolutely no pattern, won't start. The dash lights illuminate, the engine cranks fine but won't start. Sit for 10, 20, 30 minutes everything starts fine. My oil gauge was also bouncing around. The ECM is throwing; PO321, PO225, AND PO1361. I swapped in a new oil pressure sensor, new throttle position sensor (the car had also been surging at idle.) Surging and oil gauge fixed. I had heard that PO1361 was almost always the PCM. Replaced PCM with remanufactured unit, still has starting problems. The car will also SOMETIMES stumble when driving as if it wants to die and the "check engine" light illuminates. A push on the gas peddle gets through it and everything is OK. The "check Engine" light is intermittent and does not come on before or after the starting problem, only sometimes while driving with the stumbling issue.

How do I check for fuel pressure? Might this be the crank position sensor. Does the CPS fail outright or will it linger?

Have you checked the FPR

FPR symptoms vary but here is some of the more common:

Usually starts ok cold after setting overnight - longer crank time when warm with erratic idle - stumbles or stalls when slowing or at stops – can stall at parking lot speeds.

To test shut off engine remove vacuum line from FPR connector, if the inside of the vacuum line or the connector on the FPR is wet with fuel OR you smell fuel the diaphragm has a leak the FPR needs to be replaced. If you run the engine with the vacuum line disconnected you may also see fuel spitting from the FPR vacuum connector.

Where will I find the FPR?

P0321 - Ignition/Distributor Engine Speed Input Circuit Range/Performance
1361 is ign related too. common failures related to the symptoms are ICM or crank pos sensor. i usually heat them carefully with a heat gun to test.

The FPR checked out fine. What I did find as I was digging around was my front motor mount bolt has backed out of the first motor mount bracket hole and is barely hanging on to the second hole. New project takes precedence.

For the last week the Check Engine light has been on. I replaced the fuel pump relay. Before doing so I had disconnected the negative battery cable. The car did it'* little trick of not starting after running fine all morning. I left it parked all day and night. In the morning it started up just fine. I decided to drive it to the local Pontiac dealer. After having it for 3 days they've basically given up, can't find anything wrong...running like a champ, and all the code reset after I had disconnected the cable and none have reset. They did say that there was an old stored code pertaining to the EGR. They confirmed it wasn't the security system...I had thought maybe it had something to do with the VATS key. They're going to keep it for a few more days.

I had a similar problem with my car stalling, and occasionally not starting. I had a loose positive batt connection and my positive cable running to the maxifuse panel was corroded inside the insulation. I replaced all of my batt cables and the problem was fixed. Also check your starter solenoid it might be on it'* way out.

We're on a third ECM now. Keeps throwing "Exhaust Gas Recirculation (EGR) valve position sensor-range performance" but thats not going to keep the car from starting. They still have it.

So far so good, replaced the ignition control module and replaced the ECM with another one on warranty. Starts each time so far....

I've straightened out all of the code, so it'* been almost a month that no CEL has flashed after replacing the EGR. But I still have the start-no start problem with no pattern. Sometimes it just refuses to start. I'm still leaning towards the fuel pump because I can not hear it prime when I turn the engine to "ON" when it'* in no-start mode. But another clue I discovered was the power windows will not roll down when it'* in the no-start mode. Is this an indication that it'* something to do with the security system? Would the power windows be tied into that?