3100 swap problem

[jteam]

I have swapped a 1995 3100 from a Olds Ciera into a 1994 Olds Cutlass Supreme. To complete the swap I had to use the 1994 upper and lower intake manifolds and throttle body, the engine mounts, and the coolant temp sensor. The issue I am having is when I connect the battery, the injectors sound like they are spraying fuel continuously with the ignition switch off. The wiring harness and PCM in the 1994 Supreme is what was in there with the original engine. Everything plugged up to the sensors perfectly. Is there any sensor on the 1995 that is different from the 1994, that could be causing the issue? There were no problems with the original 1994 engine other than an overheating issue. I am stumped.

[IsaacHayes]

Which injectors did you use? If from an engine that sat for a while they could be seized up. Meaning they could be stuck open.

[jteam]

I used the injectors from the 1994 along with the complete lower and upper intake and throttle body (the 1995 upper an TB were different). I also used the injector wiring harness from the 1994. I have concluded from the wiring diagram and a quick check with a test light, that the pink common wire to all the injectors, must be pinched (shorting to ground) under the upper intake. Most likely by the bracket that connects the two injector rails. I have not pulled the upper yet to verify because its just too dang cold when I get home. Wed and Thurs. forecast is looking better though. I'll post back what I find. Anyone have any thoughts?

[IsaacHayes]

Well, if you have a pinched wire, that woudl be a problem! lol. Verify everything is 100% first.

[jteam]

update

I pulled the upper intake and verified that the injector harness is ok. I have determined that the fuel pump is running as soon as I connect the battery and the pressure can be heard and felt in the rails and injectors. I verified that the pump is running and also double checked with e pressure gauge. The ignition key switch is off when this occurring. I have completely disconnected the injector harness behind the alternator and even pulled the relay labeled as the fuel pump relay on the passenger side fender well in the distribution box. We did nick a couple wires (not near each other) when removing the original engine, but I have been all through that part of the harness and repaired the nicks. What in the heck am I missing? I am beginning to feel that the issue is a coincidence but everything was fine before I did the swap. My Haynes manual is just not getting the job done. Anyone have a copy of the factory wiring diagrams?

[IsaacHayes]

Yes the pump runs to prime the fuel rails and get the pressure ready. Well, when you have it to "on" before you turn it to hit the starter.

You're saying it's on even with the keys out????!??

[jteam]

Yes, it is priming to 44psi (which is within specs with the engine off) but the dang key was in my pocket and its doing so when I simply reconnect the neg battery cable. Dont make sense. all the wiring harness was already in the car with the old engine and was running fine. Heck, I can even start the donor engine thats in now. Problem is, the battery is going to die and it may wash the cylinders if the injectors are spraying (not sure they are or not) with the pump priming up like this. Looking up parts for the two engine years shows that the front crank sensor part number is slightly different but everything else is the same, and heck I even disconnected the front crank sensor and it is still pumping. Right now the coil, injector harness behind alternator, and the front crank sensor are disconnected and when the neg is connected, it pumps up. Almost sounds like its spraying the injectors also. Pulled a plug but it was not wet with fuel, just smelled like fuel. I am stumped!

[jteam]

Found it! Oil pressure sensor malfuntion

The fuel pump was getting power because the oil pressure sensor was shorting out and powering the fuel pump!