I have an '87 5.7L. Does anyone know what sensor goes on the back of the intake manifold right next to the distributor? I have done an engine swap and engine started but would hardly run...it stalled and blew a little smoke out of this spot by the distrib. I looked and there was only a hole there without anything screwed into it... I believe the MAP sensor is on the bottom of the intake on the passenger side, correct? Did this year have a MAT sensor also and maybe that is what is sposed to be there?
I plugged the hole and she still won't start. Got spark, Got injector pulse. Tried with EST plugged in and unplugged, timing bypass connector plugged in and bypass unplugged(I think this is doing the same as unplugging the EST module, right?) I set the timing to 8 degrees BTDC while cranking the engine. Am I missing anything? Anything to try? Also, does check engine light stay on with ignition on until the engine runs? I hooked up the scanner and said no codes were present...
REALLY NEED SOME HELP HERE BECAUSE IT WAS RUNNING THE OTHER DAY TWICE FOR ABOUT 10 MIN. EACH TIME. It ran pretty ruff but I am thinking this is because of the hole in the manifold where a sensor is sposed to go. I was trying to fine tune before taking it for a drive but now today she doesn't want to run at all!!!
HELP!!!!!

 

Figured out why she won't start.....NEEDS GAS!!!!!!!!! I would still like to know what sensor is right next to the distributor, on the backside of the intake manifold....not the oil pressure switch...I just stuck a new one on.

 

I can't recall there being a sensor in the area you describe. Could you be referring to the EGR solenoid?



There is no MAP sensor on '87 TPI's.

The MAT sensor is on the underside of the plenum in the back near the distributor.

 

TPI or TBI?
Got a pic?
On the intake or on the block?
Oil pressure switch is on the block



Exactly what I was thinking

 

Oil pressure is my guess. If you have a two-wire oil pressure sensor just above the oil filter, then the one your missing is a single wire oil pressure sender for the gauges. If you have a 3-wire oil pressure sensor above the oil filter, then that hole gets plugged.

 

this hole in the manifold points right at the distrib... Could this be the brake vacuum port? For right now I just plugged it and she purrs. Then when I turn it off(hasn't stalled yet, only dumped the clutch and the fire went out!) and try to restart it, she won't start back up for like 5-8 Min. Has spark has gas, has pulse, I guess it's cooling something off before it will start again??? Don't know...tried opening the gas cap, didn't help...