Absolutely going out of my mind.
#1
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Car: 86 Iroc
Engine: 305ci TPI LB9
Transmission: 700r4
Axle/Gears: 10 bolt 75/8 ring gear;3.42
Absolutely going out of my mind.
Hi. I hope I'm in the right section for this. I've been fighting my car ('86 Iroc 305 tpi V8) forever it seems. It runs lean almost all the time. The codes 36 and 44 are reoccurring. It acts up (runs nervous) when it feels like it. Sometimes it runs like a champ and sometimes it stalls at idle. There's no rhyme or reason.
I've put a new computer,
IAC,
O2,
injectors (Southbay),
fuel filter & pump,
new intake gaskets,
fixed any and all vacuum leaks,
MAF sensor,
plugs,
wires,
cap/rotor,
ignition module,
EGR valve,
temp sensor,
EGR solenoid was tested for being good (it was/is),
checked ignition timing (it's 100% correct),
fixed some wiring back to factory (someone had played in the wiring and it was all messed up),
cooling temp sensor.
It's just a lot. Does anyone have any other ideas or suggestions? Thanks, Pinupdoll22.
I've put a new computer,
IAC,
O2,
injectors (Southbay),
fuel filter & pump,
new intake gaskets,
fixed any and all vacuum leaks,
MAF sensor,
plugs,
wires,
cap/rotor,
ignition module,
EGR valve,
temp sensor,
EGR solenoid was tested for being good (it was/is),
checked ignition timing (it's 100% correct),
fixed some wiring back to factory (someone had played in the wiring and it was all messed up),
cooling temp sensor.
It's just a lot. Does anyone have any other ideas or suggestions? Thanks, Pinupdoll22.
#2
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Join Date: Jul 1999
Location: Adrian, Mi, USA
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Car: 1988 Pontiac Firebird Formula
Engine: 5.7 TPI
Transmission: 700R4
Re: Absolutely going out of my mind.
DTC - 36 MAF sensor error
DTC - 44 Oxygen sensor error (lean condition indicated)
Have you checked fuel pressure with a gauge?
How are the maf relays? Still original?
Grounds for the relay control circuits?
DTC - 44 Oxygen sensor error (lean condition indicated)
Have you checked fuel pressure with a gauge?
How are the maf relays? Still original?
Grounds for the relay control circuits?
#3
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Car: 86 Iroc
Engine: 305ci TPI LB9
Transmission: 700r4
Axle/Gears: 10 bolt 75/8 ring gear;3.42
Re: Absolutely going out of my mind.
I've checked fuel pressure with the Snap On fuel pressure gauge and it had 48 pounds.
I've changed the burn off relay and I believe the power relay (don't remember but I think so).
As for ground circuits, I back probed the whole wiring harness and it all seemed fine- per GM test procedure.
I've changed the burn off relay and I believe the power relay (don't remember but I think so).
As for ground circuits, I back probed the whole wiring harness and it all seemed fine- per GM test procedure.
#4
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Car: 1988 Pontiac Firebird Formula
Engine: 5.7 TPI
Transmission: 700R4
Re: Absolutely going out of my mind.
I *think* there are three relays over there? Maf power, maf burnoff, and fuel pump?? (its been a while.) I don't know if you can swap 'em around, but, might try that, if you can.
I suspect the maf problem is giving you the lean problem, given that fuel pressure is good.
I suspect the maf problem is giving you the lean problem, given that fuel pressure is good.
#5
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Car: 1989 Formula 350
Engine: 350
Transmission: T-5
Axle/Gears: 3:23
Re: Absolutely going out of my mind.
I had a screwy Bosch O2 sensor(right out of the box). I was dataloging it and it was throwing my Air Fuel Ratio all over the place. Swapped it for a OEM ACDelco sensor and it evened out.
#6
Supreme Member
Re: Absolutely going out of my mind.
Add the TPS sensor to your list. They can get little dead spots in them and cause intermittent weirdness. Remember in 86 they were still using the kind you had to adjust into range following factory procedure.
If you suspect the MAF, unplug it as a diagnostic. It'll run without it, but in limp-home mode (with CEL on), but it should at least run consistently.
If you suspect the MAF, unplug it as a diagnostic. It'll run without it, but in limp-home mode (with CEL on), but it should at least run consistently.
#7
Senior Member
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Re: Absolutely going out of my mind.
I recently replaced my O2 sensor with the OEM GM sensor...got it from RockAuto for less than $20.00 shipped.
I can't say for sure this is your issue, but that's pretty cheap.\
How's the play in the throttle shaft? GM didn't put a bushing in the shaft...not terribly uncommon to wear the aluminum the shaft is riding on to the point that you've created a leak between the shaft and throttle body housing, which would run the mixture lean, since the leak is past the MAF.
I can't say for sure this is your issue, but that's pretty cheap.\
How's the play in the throttle shaft? GM didn't put a bushing in the shaft...not terribly uncommon to wear the aluminum the shaft is riding on to the point that you've created a leak between the shaft and throttle body housing, which would run the mixture lean, since the leak is past the MAF.
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#8
Supreme Member
Re: Absolutely going out of my mind.
Checked for a vacuum leak? Old cars old hoses = vacuum leak.