Hesitation and power loss when hot

[Synned]

I have been having this problem for as long as I have had my car. I thought the problem went away but it was only because it was no longer summer.

During the summer, during the day my car runs so ****ty. When I get on it out of the hole it hesitates bad and then catches up to itself. The car loses all of its balls horribly. I don't understand why the temperature outside affects my car this much. Its only about 80* out, it shouldnt make my car feel like a 4 banger. Maybe a little more sluggish.
At night time it runs a lot better.
I have a feeling the computer is pulling out WAYYYY to much timing because of the heat.

What could cause this? A faulty ACT? A faulty ECT? I don't know.
I have no codes. Maybe its clogged cats or something? lol.
Should I try to run locked timing? How much?
Thanks guys
Joe

 

[jrichker]

Some easy ACT help.

At the computer connector:
Pin 25 ACT signal in. at 50 degrees F it should be 3.5 volts. It is a good number if the ACT is mounted in the inlet airbox. If it is mounted in the lower intake manifold, the voltage readings will be lower because of the heat transfer.

Pin 7 ECT signal in. at 176 degrees F it should be .80 volts

At the computer or under the hood:
The ACT & ECT have the same thermistor, so the table values are the same.

Here's the table: The values are +/- 15%, so don't get worried if your readings vary a little bit.

Voltages are measured across the two connector pins of the sensor with the sensor connected.
68 degrees F = 3.02 v
86 degrees F = 2.62 v
104 degrees F = 2.16 v
122 degrees F = 1.72 v
140 degrees F = 1.35 v
158 degrees F = 1.04 v
176 degrees F = .80 v
194 degrees F = .61

Ohms measures at the computer with the computer disconnected, or at the sensor with the sensor disconnected.
50 degrees F = 58.75 K ohms
68 degrees F = 37.30 K ohms
86 degrees F = 27.27 K ohms
104 degrees F = 16.15 K ohms
122 degrees F = 10.97 K ohms
140 degrees F = 7.60 K ohms
158 degrees F = 5.37 K ohms
176 degrees F = 3.84 K ohms
194 degrees F = 2.80 K ohms

 

[Synned]

Some easy ACT help.

At the computer connector:
Pin 25 ACT signal in. at 50 degrees F it should be 3.5 volts. It is a good number if the ACT is mounted in the inlet airbox. If it is mounted in the lower intake manifold, the voltage readings will be lower because of the heat transfer.

Pin 7 ECT signal in. at 176 degrees F it should be .80 volts

At the computer or under the hood:
The ACT & ECT have the same thermistor, so the table values are the same.

Here's the table: The values are +/- 15%, so don't get worried if your readings vary a little bit.

Voltages are measured across the two connector pins of the sensor with the sensor connected.
68 degrees F = 3.02 v
86 degrees F = 2.62 v
104 degrees F = 2.16 v
122 degrees F = 1.72 v
140 degrees F = 1.35 v
158 degrees F = 1.04 v
176 degrees F = .80 v
194 degrees F = .61

Ohms measures at the computer with the computer disconnected, or at the sensor with the sensor disconnected.
50 degrees F = 58.75 K ohms
68 degrees F = 37.30 K ohms
86 degrees F = 27.27 K ohms
104 degrees F = 16.15 K ohms
122 degrees F = 10.97 K ohms
140 degrees F = 7.60 K ohms
158 degrees F = 5.37 K ohms
176 degrees F = 3.84 K ohms
194 degrees F = 2.80 K ohms

Hey thanks, so should i test the voltage with key on or engine running?
It shouldn't make a difference whether I test at the computer or at the sensor right? Except if the wire breaks or is open I guess.

Thanks
Joe

 

[Synned]

tttttttttt

 

[Synned]

Well, measured the sensors.
The ACT sensor was a little weird, at
1.72 volts across both wires.
This was when its about 85 * out, that voltage means its like 122* out.
Could this cause the problem? Does the computer back out timing according to the ACT?