ok here goes...had a code 33 on my car...yesterday was on way home, made a stop, got back in car, wouldn't turn over...turned out the neutral safety switch was dead...bypassed it and the car started...good news there...but wait...now the computer still says code 33(disconnected battery overnight)but it gets up and hauls a$$...no bucking, surging or anything, spins it's tire well into third gear(no posi yet!) what's up?!?! Also is there anything detrimental about having the neutral safety switch dissconnected??? there are 6 wires going to it and i dont know what they all do????!?!?!?!
thank you

 

All the wires on the shifter are for the backup lights, hatch interlock and neutral safety switch. It's not really any big deal to disconnect the neutral safety switch, now your car will start in gear though. I don't know about your code 33 though.

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82 z28 350cid, vortec heads, comp 262h cam, Holley 600cfm carb, 2in twice pipes, MSD ignition, turbo 350 trans, 3.73 posi, manly b&m megashifter

 

Thanks 82z....that is good to know....now if i could just figure out that other part....wow....

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Scott Downs
85 Trans Am
305 tpi/700r4
3.73 w/255/60R15
plain firebird nose(for better engine cooling)
T-Tops, pwr everything
been to about 140mph

 

Code 33 is a bad maf or maf relay or an open somewhere in the green wire (center of connector) on the maf

And I won't forget to mention 85 maf systems are different.

And the bucking problem is sometimes the result of a maf on the blink. Setting the code sends the computer into limp-home, therefore ignoring the sensor/problem and some performace is gained back and the bucking would stop.



[This message has been edited by JoelOl75 (edited April 30, 2001).]

 

Would that explain why it is running rich....when it has been idling for a few minutes you will smell gas from the exhaust fairly strongly....

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Scott Downs
85 Trans Am
305 tpi/700r4
3.73 w/255/60R15
plain firebird nose(for better engine cooling)
T-Tops, pwr everything
been to about 140mph

 

Afoot,

Joel is all over this one. The '33' is a MAF reporting higher intake flow than what is expected by the ECM. Usually, a '34' is more common when a MAF begins to fail, but the early '85 digital MAFs were a little quirky.

The '33' can be caused by a TPS voltage that is too low, a MAF that has been altered (screens removed), a system overvoltage, a failing MAF, or MAF circuit. Since the MAf is the most expensive component (and most difficult to diagnose without an oscilloscope) you might want to check the other possibilities first.

Disconnecting the battery cleared the ECM RAM, and all data tables that you had written. The car restarted with the base parameters in the PROM, and will eventually write new BLM tables when you correct the DTC problem. In the interim, it will probably continue to run rich on the base fuel and spark tables.

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Later,
Vader
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"What a Day..."
Adobe Acrobat Reader

 

DTC problem?!?!

 

From what I have seen from your posts, I gather that you are working on an 85 T/A. I just had this exact problem on my 85 IROC. Code 33 indicates that the ECM has seen flow in excess of 45 grams/second (above 2.2 volts) for 1 second when the engine is first started, the TPS is less than 1/4 throttle, or RPM is ess than 2000. Sounds very complicated, but fairly simple to fix. Your best bet would be to go to the local garage and get a wiring schematic and diagnostic flow chart. I used the Mitchell Repair Information CD from the garage that I go to. Follow the flow chart step by step. I got half way through the chart and discovered an open ground. Finally found it at circuit D12 at the ECM. IROC runs like a champ now. On 85 only, the MAF circuit does not use relays. It uses control module that piggy backs to the ECM. This module controls the MAF power, burn off, and whatever else it needs. Can't miss it. If you need one, good luck. The only place to get it is GM, $921!!!!!!!!
GM did alot of weird stuff to these 85's, but it still has the most HP out of the 305 engines at 215. Hope I could be of some help to you. Good Luck!!!!

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Rob Kowalski
85 IROC, 305 TPI, JET AFPR - 45 PSI, B&M Megashifter, B&M Shift Kit, 3.42 gears, SLP Airfoil, SLP 1 5/8 headers and cat back system, gutted cat, gutted airbox, MAF screens removed, K&N, more to come!!

 

That's cheap!! The dealer here wanted $961 for the burnoff module!! The best thing I've done to my car was switched over to the '86-'89 setup. That module now sits in the top of my toobox.

I have the troubleshooting schematic here and can scan and e-mail it to you, just let me know.


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Kevin Irving
85 Trans Am WS-6, 305 TPI, custom burned '86 PROM with '87 "165"ECM, Accel Supercoil & 8.8 Wires, Rapidfire #2 @ .055", MSD 6AL, 1.6:1 Roller tipped rockers, Homemade AFPR, K&N cone, no airbox, Aluminum Driveshaft, Wonderbar, TB Coolant Bypass, Ported Plenum, Descreened MAF, Syclone Fuel Pump, JET Airfoil, Mobil 1 synth in all but transmission.

15.556 @ 86.65mph, Nov 10, 2000.... I know it sucks.. but it will get better!

http://www.geocities.com/transam85tpi/

Member - The Tidewater Trans Am Club, Norfolk VA http://www.geocities.com/ttacva/

 

Thanks plenty guys...sounds like y'all really know this stuff. Kevin i would most certainly appreciate that schematic....hope i can figure it out!!! Thanks again everyone!!

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Scott Downs
85 Trans Am
305 tpi/700r4
3.73 w/255/60R15
plain firebird nose(for better engine cooling)
T-Tops, pwr everything
been to about 140mph

 

Oh yeah here is my email---scottiandowns@hotmail.com....

 

hey Kevin did ya forget about me?? I would most certainly appreciate that troubleshooting schematic...Thanks

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Scott Downs
85 Trans Am
305 tpi/700r4
3.73 w/255/60R15
plain firebird nose(for better engine cooling)
T-Tops, pwr everything
been to about 140mph

 

DTC = Diagnostic Trouble Code. When people say the computer has a 'code' they mean it has a DTC - atleast for GM computer systems.

Laterzzzzzzzzzzzzzzzzzzzzzzz

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Matt

1987 GTA L98 MD8 GW6

"Stop Lights timed for 35Mph are also timed for 70Mph"

 

89 Iroc z i am having a horrid bucking problem, so far ive changed all vaccuum lines, distributor cap and rotor, plugs and plug wires, and i have a brand new MAF from a 350 86 firebird formula (i didnt see a differnece in performance from the firebird maf to mine, so i dont think it is a maf problem...

would could the possibilities be? how would i find a loose ground and fix it? is it expensive???