I was on my way home from work Friday and noticed that when Ii hit a bump the SES Light would come on then go off. It did it again today and the car shut off. Wouldn't start and when it did it only ran for a few seconds then shut off. After a tow truck ride home, I was able to start it and drive it into the garage. It finaly had a rough idle and died. I checked the codes and got a code 33. Maf or Map code, What does this mean? The book says signal voltage or frequency is high during engine idle, (engine mis-fire or unstable idle may cause this.) OK, but whats causes the unstable idle, dumb a$$es? EGR valve is about a year old. O2 sensors about 3-4 years old, only about 35,000 miles on them. I installed a new 02 sensor today, no luck. I checked the fuel pressure and had none. I checked the voltage at the relay with the relay out and was getting voltage. I don't see a way to check the voltage with the relay plugged in unless I splice into the wire. Should I get a new relay first? Or is there anything else I can check? Fuses are good. Any help is greatly appreciated, Thanks Ron.



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91 Formula WS6
Home Made Ram Air,K&N Air Filter,Air Foil,
Ported Plenum,Underdrive Crank Pulley, Crane AFPR, Edelbrock High Flow TPI Runers, Holley 19lb Fuel Injectors, MSD6AL, SLP Headers, SLP Y Pipe & Complete SLP 3" Exhaust and Muffler, High Flow Cat, Mobil 1 Oil, Hotchkis STB, Spohn LCA's and Panhard Bar and other polyurethane goodies.

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Add your 91 F-Body to my 91 F-body's Links page, or be added to my F-Body Links Page.

 

make sure your tps is set correctly,, also make sure your connections to the maf are clean and there are no air leaks.
ron

 

I tried to check the voltage at the TPS, either I'm not doing something right or not getting a good connection to the wires or the TPS is bad, cause I'm not measuring anything at the TPS. How much are TPS? I did the spraying of the carb/starter cleaner around the MAP sensor area when the car would run, and no idle differences.

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91 Formula WS6
Home Made Ram Air,K&N Air Filter,Air Foil,
Ported Plenum,Underdrive Crank Pulley, Crane AFPR, Edelbrock High Flow TPI Runers, Holley 19lb Fuel Injectors, MSD6AL, SLP Headers, SLP Y Pipe & Complete SLP 3" Exhaust and Muffler, High Flow Cat, Mobil 1 Oil, Hotchkis STB, Spohn LCA's and Panhard Bar and other polyurethane goodies.

Http://www.geocities.com/91formula

Add your 91 F-Body to my 91 F-body's Links page, or be added to my F-Body Links Page.

[This message has been edited by Ron Mullins (edited May 01, 2001).]

 

If the TPS is bad, it could cause that problem. They are about 35 bucks. Check to make sure the TPS is getting a 5v signal in, I forget which wire that is but I think its the gray one.

 

Believe it or not a bad fuel pump caused a code 33 on my car about a year and a half ago. My mech plugged in his scanner and we could watch the BLM climb like a rocket because the ECM was practically begging for fuel, and somehow he figured out that it was the fuel pump. He changed it out that weekend and the code went away until the burnoff module decided to go on vacation.

But like Ron and the others said, check your TPS. You don't have a MAF sensor so you should check for vacuum leaks around the plenum and the MAP sensor (little black box on the back of the passenger side of the plenum.)

Also, go ahead and replace the relay, it's only about $9 at any parts store. Too bad you don't have MAF... you could have just switched the relays

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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/

[This message has been edited by Kevin Irving (edited May 01, 2001).]

[This message has been edited by Kevin Irving (edited May 01, 2001).]

 

I am having a hell of a time with my car idling way to fast. I was plaing with it last night and in a frusterated fit I was tugging on the throttle linkage and I found it brought the idle down to where is was supposed to be. I think it might be the TPS now......sounds like you are having the opposite reaction of my problem. I know that the engine normally messes up really bad when it goes.

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91 Z28 Camaro
305 TPI
Flowmaster 3" exhaust
700R4 with 2000 Stall and shift kit
One sweet sounding system

 

Do you have to check the voltage to the TPS with it plugged in or can you unplug the TPS and check the voltage at the wire? The only way to check the voltage with it plugged in is going to be to splice into the wires. Something I really didn't want to do.

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91 Formula WS6
Home Made Ram Air,K&N Air Filter,Air Foil,
Ported Plenum,Underdrive Crank Pulley, Crane AFPR, Edelbrock High Flow TPI Runers, Holley 19lb Fuel Injectors, MSD6AL, SLP Headers, SLP Y Pipe & Complete SLP 3" Exhaust and Muffler, High Flow Cat, Mobil 1 Oil, Hotchkis STB, Spohn LCA's and Panhard Bar and other polyurethane goodies.

Http://www.geocities.com/91formula

Add your 91 F-Body to my 91 F-body's Links page, or be added to my F-Body Links Page.

 

Take some needles and place them in the top and middle holes in the connector where the wires enter. Then just clamp the leads from your voltmeter onto each needle.... it works

 

Well, I gonna replace the TPS tomorrow and wee what happens. I checked tonight by putting some needles into the plug to get connection and didn't ready any voltage. So I'll keep you all posted what I find out in the morning.

Thanks again for everything, Ron.

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91 Formula WS6
Home Made Ram Air,K&N Air Filter,Air Foil,
Ported Plenum,Underdrive Crank Pulley, Crane AFPR, Edelbrock High Flow TPI Runers, Holley 19lb Fuel Injectors, MSD6AL, SLP Headers, SLP Y Pipe & Complete SLP 3" Exhaust and Muffler, High Flow Cat, Mobil 1 Oil, Hotchkis STB, Spohn LCA's and Panhard Bar and other polyurethane goodies.

Http://www.geocities.com/91formula

Add your 91 F-Body to my 91 F-body's Links page, or be added to my F-Body Links Page.

 

IF YOU WANT TO TEST WIRES WITHOUT CUTTING THEM, STAB THEM WITH SEWING NEEDLES SO THEY STICK, AND TEST THE VOLTAGE AGAINST THEM.