Murphy's acting up again.

[Sonicfrog]

Yep, Murphy the $500 87 T-Wag is being a little moody. When cold it runs fine. When it warms I get some lag in acceleration. Also sometime it feels like there is a speed limiter installed and it doesn't want to go past 73 mph. I'm fairly certain the TPS is part of the problem. I have cleaned the terminals and that has seemed to make things better temporarily, but I know the pins are pitted and the contacts probably build resistance as they warm. I do have another TPS from a GL (year unknown), and the connections are a bit different. The one in Murphy has two wires connected to the top of the TPS and a white and black wire set that connects on the side. The spare TPS does not have the black / white wires. I wonder if those were used for the crappy auto tranny's passing grear? Any thoughts?

[Skip]

the passing switch is under the dash

 

your spare TPS may be from a vane type MAF

 

I'd start looking at the exhaust being plugged or

maybe the fuel filter

[Gloyale]

The pins on the body of you're TPS are the Idle Switch contacts:

 

Black is ground

 

Blue w/white stripe is idle switch signal (grounded when throttle closed)

 

 

 

The 3 wires in the separate pigtails are the Potentiometer wires:

 

White is power

 

Black is Ground(spliced to idle switch ground wire a few inches up in the harness)

 

Green is Signal volts

 

 

 

 

 

A standard non-turbo, SPFI, TPS could be wired to all the corresponding contact for use. But it ouputs in a different range, in the opposite manner.

 

MPFI/Turbo ressitance goes from very high(17.8k ohm) closed to low(1.5k ohms) open

 

SPFI goes the other way from low(1k ohm) to high(2.4k ohm) open. Opposite, and a much lower and narrowed scale

[Sonicfrog]

I don't think it's a plugged exhaust. I've had that on another car and this just doesn't feel like that. The fuel filter isn't that old, but they're cheap, so I'll replace it anyway.

[Sonicfrog]

Murph is doing much better. This weekend I replaced the fuel filter. Friday night, while at the parts store to get the filter, I found myself trying to think of the last time I replaced the disty cap and rotor..... couldn't remember. So I decided to get those too. Well, they didn't have the fuel filter of coarse, and it took them twenty minutes to find the right rotor and cap (they list five for the turbo) and then, just when I was ready to purchase...... the power went out!!!:-\ Figures. I couldn't buy the parts as all the registers are computers and... well, you know. So I got the parts today, found the fuel filter at Napa, and now Murphy runs a heck of a lot better. There is still a we bit of a pause in the acceleration, but it's barely noticeable.