I've got a 87 or 88 5.0 TPI in a 67 C10 Truck.

She starts and Idles nicely. But when I give her any throttle at all she stumbles and dies.

This use to be an intermittant problem. It would even happen while driving. Now it's constant and I cannot drive her at all.

When I could still drive her, she always suffered from delayed throttle response.

I bought an OTC 2000 Scanner but I'm getting "NO DATA". Hopefully I'll find time to trace the ALDL wiring back to the ECM this weekend.

So I tested the TPS as I had before. I'm getting 0.65 volts at idle. But as I approach it goes just over 4.0 volts then I get O.L. (open lead) at WOT.

Is my TPS bad? Or do I need to adjust something on the TB or TPS?

 

any O.L in the tps range between .54 and wot ( 4.0- 4.5) depending. Should be replaced

 

Agreed, replace it.

side note; I've had my scanner on about 4 or 5 TPI ECMs and two of them would give the "no data" screen. Both had the ECMs replaced and now both read data just fine.

 

Crap! I sure as hell didn't want to hear that. But thanks for the info.

I'll replace the TPS.

 

I installed a new TPS today. I have it at 0.71 volts closed and it goes smoothly to just over 4.0 volts WOT.

I fired her up and had the same symptoms.

I took the neg cable off the battery, maybe that'd help.

While I waitedI traced the aldl wring and did a continuity test from the ALDL Test and data terminals (B,E,M). Wiring tested fine to the ECM connector. I noticed the longer connector tab was not engaged so I firmed up the connections.

I reconnected the battery, fire her up and shes a little better. I drive her around and after a while all symptoms are gone. even the stumble I had when I'd decelerate rapidly.

So I decided to try out my scanner. I don't get "No Data" anymore. Now I just get "wait". I've waited about 15 minutes now and it still reads "wait".

 

I go back after the last post. Now reads "no data".

She drives fine now. Could I still have a bad ECM?

 

If your problems are gone i would suppose not, sometimes these old cars are fussy, try moving the connector a bit and see if it shows it.

And yeah u reset the ecm when u disconnected the battery, then u let the computer relearn everything while u drove. Thats why its gone

Glad its fixed, i wish myn was that easy.. lol

 

Yeah. That's the good part. My truck runs now fine.