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Topic: I need some help with this Oldsmobile (Read 1190 times) previous topic - next topic

I need some help with this Oldsmobile

I know its not a ford but I know you guys are smart and i hope a couple of you have worked on one of these before.
The car is a 1988 oldsmobile cutlass ciera with the 3.8L SFI

The problem is at light throttle the car runs like , it misses really bad and it had been stalling out while driving. The only codes thrown were 12(normal), 23 (intake air temp), and 34 (mass air sensor). The problem there is those were disconnected by someone while my mom was stalled out he stopped and disconnected them and they drove back home. I havent been able get the codes to clear, even after taking the ECM fuse out for like an hour I guess i am going to have to pull the - cable on the battery to see if the codes come back after clearing them.
She took it to the shop where she got it and they changed the injector o-rings and then about a week later while it was still doing it took it back and they took all day to say it was dirty injectors(which supposedly got cleaned). I am thinking its the injectors internally leaking/not working right, cause it loses fuel pressure after a little while and there are no leaks in the fuel lines.
I checked the TPS and it had a dead spot so i replaced it but it didnt change anything.
Everything i have read as far as repair info(mitchell on demand, and the autozone repair guide) says that the TPS sensor should go from .4V at idle to 5V at WOT, but when i checked the one on there it was backwards at idle/not running it was 4.8V and went down at WOT. 
Does anybody know for sure if its supposed to go from .4V to 5V or 5V to .4V?

Thanks

I need some help with this Oldsmobile

Reply #1 –
How are you checking loss of FP?,Was it warmed up before you took the codes.I know on the v-8s the wires to the injectors weaken at the mount on the cfi.It is cfi right?
Old Grey Cat to this.88 Cat, 5.0 HO, CW mounts, mass air, CI custom cam, afr165's, Tmoss worked cobra intake, BBK shorty's,off road h pipe, magnaflow ex. T-5,spec stage 2 clutch, 8.8 373 TC trac loc, che ajustables with bullits on the rear. 11" brakes up front. +

I need some help with this Oldsmobile

Reply #2 –
sorry didn't read thru "SFI"
Old Grey Cat to this.88 Cat, 5.0 HO, CW mounts, mass air, CI custom cam, afr165's, Tmoss worked cobra intake, BBK shorty's,off road h pipe, magnaflow ex. T-5,spec stage 2 clutch, 8.8 373 TC trac loc, che ajustables with bullits on the rear. 11" brakes up front. +

I need some help with this Oldsmobile

Reply #3 –
Well i dont have fuel pressure numbers but i know that it is not holding pressure after the car is shut off. Yes it is SFI with the distributor less ignition. I checked the each coil pack and they checked out alright. What i dont understand is why the TPS is "backwards".

I have taken the codes about 10 times at various times so some of them were when it was warm and others weren't. I performed a cylinder balance test and the results were not conclusive. I dont have an external tach but it none of the cylinders really caused any noticeable difference. I didnt want to but i suppose i am going to have to just pull the - cable to clear the codes, cause i had the ecm fuse out all night and the codes were still there. I cant tell if its not throwing a code at all or if it keeps throwing the 23 and 34 codes. There is no KOER test for it the only thing that does is tell you if its in closed loop or open loop.
I thought maybe fuel pump going but it doesnt make sense to me why it would do it at part throttle with no load.

Thanks for the response.

I need some help with this Oldsmobile

Reply #4 –
Is this obd 1?. I work on bowties older ones trucks V-8,not sure what the cars got,seems 88 is on the verge of mass air.Trucks don't have it till 96.
Long day they did have it,I'm stuck on ford .I got to rethink this,sorry.
Old Grey Cat to this.88 Cat, 5.0 HO, CW mounts, mass air, CI custom cam, afr165's, Tmoss worked cobra intake, BBK shorty's,off road h pipe, magnaflow ex. T-5,spec stage 2 clutch, 8.8 373 TC trac loc, che ajustables with bullits on the rear. 11" brakes up front. +

I need some help with this Oldsmobile

Reply #5 –
RE read,I had fuel pumps go on !#@$ sorry couldn't type that word again.More slow than just dead.Recently I did have a code + some for mass air on a 94 replaced the ma and lost the rest.
never really had to read a tps yet to answer that ?.
Parts are just as $$ for those things to, like our cars.
Old Grey Cat to this.88 Cat, 5.0 HO, CW mounts, mass air, CI custom cam, afr165's, Tmoss worked cobra intake, BBK shorty's,off road h pipe, magnaflow ex. T-5,spec stage 2 clutch, 8.8 373 TC trac loc, che ajustables with bullits on the rear. 11" brakes up front. +

I need some help with this Oldsmobile

Reply #6 –
If you need me to re explain anything i can try to find better words to describe it.
It is baffling me. Granted i dont have a lot of hands on experience with diagnosing this type of stuff yet, but I do have a degree and did very well with the class work and the hands on.
If you push on the pedal about 1/16 to 1/8 of the way down it is like its only firing on 2 cylinders, but if you push it down a little further to almost half it will run nice and smooth. Now if you push it down past half it will do nothing and if you dont let off it will completely stall out.
Thanks again

I need some help with this Oldsmobile

Reply #7 –
You said you got the code for MA if you didn't change it it probably that is it.you got a ford if it's mass air it will run like  unhooked,if it would run at all .mine does but like .
Sounds very simaler to what I had recently.Worst when its just started,Isn't 34 a oksy ? I'm guessin  now.
Old Grey Cat to this.88 Cat, 5.0 HO, CW mounts, mass air, CI custom cam, afr165's, Tmoss worked cobra intake, BBK shorty's,off road h pipe, magnaflow ex. T-5,spec stage 2 clutch, 8.8 373 TC trac loc, che ajustables with bullits on the rear. 11" brakes up front. +
 

I need some help with this Oldsmobile

Reply #8 –
23 is the IAT sensor and 34 is the Mass air sensor