Hello everybody and Merry Xmas!

I have a few more questions about things that leave me puzzled.

I have replaced the temp 2 and the o2 sensors as well as the ICV.

At cold start the engine briefly surges to 1000 rpm and then drops to around 650.

When I pull the plug of the temp 2 it goes up to around 850rpm - ???

The car runs good once it reaches operating temperature.

Before I replaced the temp 2 (Oem Bosch) the rpm increased slightly when I turned on the A/C, after the replacement it stays the same.

At cold start it is running way too rich judging by the acrid smell of the exhaust fumes. It gets better once the engine warms up.

What did I miss?

 

Have you checked the temp 2 readings at the ECU ? And at the sensor? Your problem sounds like a temp 2 issue, but if its new, unlikely, unless its related to the wiring from the sensor. Usually if its very rich cold, it will die as it warms, as it effectively gets richer as it warms.
jp 83 Euro S AT 55k

 

I have not measured it at the ECU. My multimeter is messed up, I need a new one. I just went and bought a new temp 2 because the symptoms were a close match, but it didn`t really do anything.

When I pull the plug of the temp2, the rpm increase...

Also, I went and regapped the spark plugs today, for the lack of better things to do. They were white-ish. It appears that I was wrong about the rich part, because they should have been black.
I guess the smell is because the the cats are shot.

 

Pulling the temp2 connector = high resistance (open) = its cold, so lift idle, but would also expect it to richen somewhat. Check the temp2 resistance - approx 3k cold, dropping to ~300 ohms hot is usual range.
jp 83 Euro S AT 55k

 

So I ran to Home Depot this morning and bought a new multimeter.
At the 20K ohm setting the new sensor measures 4.64K cold.

checked the old temp2, it measures around 5K cold.

Have not started the car yet.

What are the points at the ecu to check for the temp 2 values?

 

On the 85/86 Temp II to ECU's
LH female connector, pins 2 & 17
EZF female connector, pins 23 & 18

Note: pins 17 & 18 are ground at ground point MPIX, its at rear of block under Air Box

Looking at the connector on the Temp II, pin 1 goes to pin 23 and pin 2 goes to pin 2 on LH

Merry Christmas

 

Thank you sir, muchobliged! Happy Holidays,!