running rich cannot find out why

[milleraj119]

did a motor swap from a 87 to an 88 drove it to work for like 2 weeks ran fine then randomly statrted to sputter and clear out and idel really rich with a lot of black smoke then run smooth back and forth then sometimes ran fine for like 10 to 5 mins then choke and jerk agian when it was running rich and blowing black smoke i could turn the key off really fast and turn it back on and it would run fine agian for another five minuts changed just changed both fuel pumps and filter changed map sensor iac and the box attached to the distributer checked all grounds changed just about all sensers easly seen with hood poped even swapped out computers did nothing checked compression plug wires and coil all have good spark. changed the 02 ran 100% better for about 2 days and now it is doing it again but not has much still have to turn the key on and off really fasst and it runs agian also changed the internal fuel pump switch under the passenger glove box

do u think it could bee a fualty o2 agian tomo i am checking the fuel pump regulater but i dont thing that is the problem


PLEASE help getting really mad and about to blow the thing up lol seroulsy

 

[IMenriched]

did a motor swap from a 87 to an 88 drove it to work for like 2 weeks ran fine then randomly statrted to sputter and clear out and idel really rich with a lot of black smoke then run smooth back and forth then sometimes ran fine for like 10 to 5 mins then choke and jerk agian when it was running rich and blowing black smoke i could turn the key off really fast and turn it back on and it would run fine agian for another five minuts changed just changed both fuel pumps and filter changed map sensor iac and the box attached to the distributer checked all grounds changed just about all sensers easly seen with hood poped even swapped out computers did nothing checked compression plug wires and coil all have good spark. changed the 02 ran 100% better for about 2 days and now it is doing it again but not has much still have to turn the key on and off really fasst and it runs agian also changed the internal fuel pump switch under the passenger glove box

do u think it could bee a fualty o2 agian tomo i am checking the fuel pump regulater but i dont thing that is the problem


PLEASE help getting really mad and about to blow the thing up lol seroulsy

yes check the FPR, { fuel pump regulator}, pressure wise, you should be in the neighborhood of 30-40 psi. you can also do a quick check by pulling off the little vacuum line on the FPR itself, if fuel dribbles out, replace it.

wouldn't hurt to check over the vacuum lines too.

the issue you maybe having is (if I'm understandin correctly) is that the 87 engine has a EGR on it and your 88 engine did not....so if you swapped out the ECM's (computers) and you defuncted the EGR to work with 88 ECM...the 87 ECM is looking for the EGR signal and not getting any.

Most folks have issues going the other way....putting a newer ECM (88' & up), into a older unit/engine, (87' or older)

ALSO make sure that your ground near the ECM is good and connections on ECM are all good too. but you seem to covered that.

it maybe time to put fresh plugs and wire on, concidering the resent overfueling.

ALSO, might be wise to check the coolant sensor for the for the ECM...not the one for the guage cluster, it has nothing to do with one feeding info the ECM. If it the coollant sensor for the ECM, is underreading temperature or not working, the the ECM continues in HIGH fuel delivery.

 

[AllanD]

Yeah, if you are still running the '87 PCM it won't be "happy" that the EGR isn't responding and it goes "apeshit" in overreaction to this.

Swap in an '88 computer and all will be good.

If it's not your problem lies elsewhere

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[RustedRanger]

Mine had a similar problem and I nearly went nuts and broke trying to find out why. Do check what the other guys said but my problem was a broken ground wire in the bundle of plug-ins on the drivers side wheel well and someone had taken of the EVAP solenoid and ran the line from the EVAP cannister directly to the throttle body so anytime I gave it gas it was sucking gas from the cannister. I guess it can do the same if that solenoid fails. Also be sure to unhook the battery after you change parts to clear out the computer. Mine was fixed and ran a little better but after "clearing" the computer it started running much better. Until I found out the problem I replaced many parts and ended up fouling out 2 sets of sparkplugs and replaced the O2 sensor twice,and have changed the oil 4 times all in 3 months....not cheap!

 

[milleraj119]

OK i am curently running the 88 computer just swapped out the 87 comp to see if it ran better then but the 88 back going to check canister and fuel regulater right now ill let you guys no if it fixed it or not