Continued issue when car hits 125 degrees

[LGAFF]

Still having this issue with the car, within about 3-4 minutes of startup, when the car hits 125 degrees, without fail....the car sputters, and misfires, the alt readings drop and flutters. Once the car hits 3K RPM the engine corrects and the problem never comes back until the next time the temp drops below 125.
*Replaced 02 Sensor
*Checked 02 grounds
*Replaced primary fuel pump relay
*tried a different chip
*tried a different ECM
*Changed the plugs
*Checked fuel pressure with car off primary and 2ndry(it still hauls *** so unlikely a fuel issue)

[mike100]

Do you think the coolant temp sensor is reporting accurately? check the plug for it too.

[LGAFF]

Yep its working, the coolant temp moves up and down as appropriate....there must be something that occurs at 125 degrees that is causing the issue....

For example the fuel pumps go back and forth at 167 degrees....I believe the 2ndry starts the car and transitions to the primary

Not sure whats going on....

[XfireZ51]

Originally Posted by LGAFF

Still having this issue with the car, within about 3-4 minutes of startup, when the car hits 125 degrees, without fail....the car sputters, and misfires, the alt readings drop and flutters. Once the car hits 3K RPM the engine corrects and the problem never comes back until the next time the temp drops below 125.
*Replaced 02 Sensor
*Checked 02 grounds
*Replaced primary fuel pump relay
*tried a different chip
*tried a different ECM
*Changed the plugs
*Checked fuel pressure with car off primary and 2ndry(it still hauls *** so unlikely a fuel issue)

125F is 51C which is when the motor goes closed loop. Very likely going lean.

[LGAFF]

Dom,

Is there something tied to the O2 sesnors in the ECM that could be bad, I tested the ground(middle white wire) and it was good

[LGAFF]

Going lean because of the 02?

A fuel injector is not going to get better, neither is a pump....unless its a relay...primary replaced...I would think if the engine transitions from the secondary to primary the issue would be the primary relay or pump

if it were the pump....it would not go away

the issue lasts 30 seconds then gone

[XfireZ51]

Originally Posted by LGAFF

Going lean because of the 02?

A fuel injector is not going to get better, neither is a pump....unless its a relay...primary replaced...I would think if the engine transitions from the secondary to primary the issue would be the primary relay or pump

if it were the pump....it would not go away

the issue lasts 30 seconds then gone

Yeah I know. It's none of those.

[LGAFF]

I am going to replace the extension harness....are these heated 02s on the 90?

[LGAFF]

I tested the 02s with the tech I, they tested ok....and they give a reading

I thought I had a bad P/S o2.....it was the first to show lean on the tech 1

Its hard to analyze an issue that lasts 30 seconds....

[Franke]

The O2's are heated according to the FSM. Should be 3 wires.