87 v10 cranks then dies

[caden_cochran]

Okay so i have a 1987 chevy v10. Whenever i crank it up it will spit black smoke and misfire real bad and barely idle then after a few seconds it goes away and runs completely normal. I have replaced almost every sensor throttle bodies been cleaned new injectors, new iac, distributor is new and the cap, fuel pump is new ignition control is new coil is new map sensor is new knock sensor is new electronic spark control is new. basically almost ever sensor/module is new. Any ideas anyone i have zero clue what it could be but there may be sensors idk ab so ask away.

 

[Snoots]

I don't know much about throttle bodys' but I believe they do have a IAC. I've known injected engines that had similar problem(s) and it was a dirty IAC.

 

[fast 99]

Really sounds like it is loading up with fuel. My first thought is injectors, but you have replaced them.

Good grounds?
Fuel Pressure?
How about the EGR?
Vacuum leak?
Low manifold vacuum will cause the MAP to dump excessive fuel.
Is it possible to monitor the manifold vacuum and coolant temp data?
It's a long shot but do you have another PROM to try?
Does it have excessive AC voltage?

 

[Strick]

Check the CTS on the intake by the water outlet (thermostat housing). The wire often corrodes or breaks. The ECM will get a reading of -40 or so if this happens; richening the fuel mixture and causing a flood situation. You could clean that connection or replace the eyelet and CTS if its rusted up or corroded.

Strickland

 

[caden_cochran]

The cts did go out on me but it’s already been replaced. egr valve is new and also i cannot seem to find any vaccum leaks. the iac is also new. i rebuilt the fuel pressure regulator too. I honestly do not know how to monitor the manifolds vaccum. what is a good way of doing it? i am assuming a prom is something to do with the ecm. We have plugged up a different ecm and it ran the same. I heard something ab the oil pressure sending unit having a part in this problem but i do not know. also grounds should be good to.

 

[caden_cochran]

It’s really weird it’s like flooding it’s self out but then levels out and runs perfect besides like a little stumble at idle every once and a while.

 

[fast 99]

Another thing to try is disconnecting the MAP. Computer will substitute data. Is a scan tool available? Would help to know the CTS, MAP and TPS data.

 

[caden_cochran]

No i do not have a scan tool it’s obd1 there pretty expensive and hard to find. someone also ripped out the check engine light.