92 hard to start when hot

[old_master]

The three wires at the TPS are Black, grey and dark blue, probably some fading going on Might want to double check and measure again Let us know what range your ohm meter is on when you check the resistance.

Black wire goes to PCM connector "A" pin #11
Grey wire goes to PCM connector "C" pin #14
Dark blue wire goes to PCM connector "C" pin #13

The purple wire on the ECT sensor goes to PCM connector "D" pin #2
The yellow wire goes to PCM connector "C" pin #10
This link explains how the ECT sensor works: http://www.aa1car.com/library/coolant_sensors.htm

If you look very closely at the connectors, the pin numbers are there. Make sure you have the correct wire and pin.

[Jerry80871852]

I was on the ECT sensor leads that hooks to the computer, per what you said in post # 42 which is pasted below, not the TPS.

Seems you switched on me or I'm confused.

old master wrote:
"Your voltage reading at the ECT sensor connector between the purple and yellow wire is correct which means both wires are good back to the PCM. It does not necessarily mean the connection at the ECT sensor is good. That can only be checked by disconnecting the PCM and measuring resistance between the purple and yellow pins in the PCM harness connector with the ECT sensor plugged in. The ECT sensor is a thermister, (a resistor that changes resistance as temperature changes). After the engine has been off for 8 hours, disconnect the ECT sensor electrical connector and measure the resistance between the two pins on the sensor. Then bring the engine to operating temperature and measure resistance between the two pins in the sensor again. Post both of your resistance readings along with the ambient temperature when you took the readings, and we can tell you if the sensor is responding correctly, and what the coolant temperature is."



about 2 hours later outside temp is 53º

2nd purple wire to yellow wire reads: 1.406

[old_master]

Sorry, didn't mean to confuse, I just posted the TPS stuff because at one point you were looking at a possible problem with it.

1.406 hmmm are you sure the meter was on the ohms scale?

At 53 degrees Farenheit, the resistance across the two pins in the ECT sensor should be around 5600 ohms. Remember to unplug the sensor and touch the probes directly to the pins. To check it at the PCM, unplug the PCM, connect the ECT sensor, and touch the probes directly to the pins in the PCM harness connector. Both ways should be very close in resistance.

This link will show the resistance values at various temps, both Centigrade and Farenheit.
http://www.explorerforum.com/photopo...g&ppuser=42004

[Jerry80871852]

That's OK. I may not be explain what I do all that good.

Maybe I got a bit confused, this is much for me, give me one without a computer, & I would feel at home, yet maybe I'm getting just a bit of a grip on trouble shooting this thing with a computer. Yet it makes me long for my cars of yesterday, for I was at home with them when opening the hood when you had the simple firing system along with a carburetor such as the Rochester 4 Barrel Quadrajet & I would feel at home

I can't help but think of a long time mechanic at the local Chevy house that has many fans, they love for him to do the work on their cars. Yet, when the computers came in, he did not take to them good at all. Of course he is older than my 64 years, probably now at about 75, while still working about 2 to 3 days per week. He does not get involved in the computer games. I might say, he can still tear an engine down and put it back together & or a brake job better than most younger mechanics & he is still strong as an ox. He is one reason they have many repeating customers throughout the years. I might add the younger mechanics looks up to him & goes to him for advise on his days at work.

During this ordeal I can appreciate him and his dislike of computerized cars & why he does not care to tackle them. Anyway, I just want to say thanks for your help & patients.

All of these reading came from the lead unhooked from the computer under the dash, with the leads hooked up to the sensors at the engine.

I'm using this multimeter set to the 3 selection to the right of off to check the resistance. If wrong please let me know.

Resistance on TPS leads to computer, with leads unhooked from computer: with leads connected to TPS.

Black to gray - 2.91
Dk Blue to gray - 2.41
DK blue to Black - 1.237

Resistance, ECT sensor lead, purple to yellow, at computer now shows 2.89

[old_master]

Something isn't right, either the sensor or the tester is screwy.

Set the tester to OHMS, (right where you had it). Touch both probes of the tester together, should read zero ohms. If it does, unplug the ECT sensor and check the resistance between the two pins in the sensor and post your results. If the tester doesn't show zero when you touch the probes together, the tester is not reading correctly...time for a new one.

[Jerry80871852]

I got my TPS sensor, installed it. I've driven it 2 times. Last night I drove probably about 35 miles, all went well, no high idles, it run great. Today I drove it about 18 miles and when I pulled into my driveway it was idling very fast. I left it running and got out, raised the hood, pulled the connector off the TPS and it idled down a bit. The engine seems to be running pretty smooth, no missing at all, if not for the high idle at times all would be well.

Having had the computer disconnected the code is gone, and so far it had not produced another one. If its going to throw a code wonder how long it might take?

I ordered a manual hopefully with the breakdown it gives I will I will comprehend all of this a bit better.

[Jerry80871852]

The cable from the cruise control to the throttle was causing my throttle to hang. It seems to be OK, yet when its hooked up, the throttle will hang when the TPS is reading about 3.38, unhooked, it goes to over 4.5 smooth as silk.

A person might not notice it hanging with the breather hooked up, or unless they're checking voltage on the TPS. Of course if you going down the highway and floor the gas pedal you'll notice it.

Still have not got the high idle conquered, with the weather getting a bit better, & the days getting a bit longer I will call a friend & see if we can set a time that he can hook up his computer. He works for a out of town Chevy house, during this time of year its dark by the time he gets home. When problem is found I'll let y'all know.