Bit of an air, fuel, throttle, temp gauge, problem.

[delatlanta1281]

Okay,
I will start with what I have attached to the car.
m30 afm
IE afpr
19 lb injectors
mark d chip, with a 173 ecu
splitsecond lamda gauge.
A temp gauge flicker.

Here is what has been happening over the past week
When I start the car it is fine, it runs strong, and there is no stumble. the ss a/f gauge swings like it should.
SOMETIMES the temp gauge flickers and climbs to the red and pegs. Here is the weird part.... the a/f gauge will peg full lean, and the car won't rev over 3500 rpm in any gear. Then, the temp gauge will flick back down causing the car to run normal and the a/f gauge to swing normally again. the only code I have gotten is the 1223 (temp sensor). I have replaced it with a brand new one and have inspected the wiring. This really only happens when it's at operating temp. I am told it could be my afm, but I have a spare and have been clicking around with the range, and it hasn't really helped. I was also told it could be a coincedence that the gauge and the throttle are acting up causing bogging, due to an SI board issue. If this is so, why does it only happen when the gauge pegs????
The only thing I can think of would be the chip, or the ecu.
If anyone has experienced this phenomenon please shed some light on this for me.
Mods, please leave this here for a bit as I have searched and no answers have been revealed.
THX
Rich

[e30frosh]

I would try an si swap. My temp gauge was flickeriong and would peg sometimes when the board was bad. I didn't log the reving issues though. It may also be some ecu issue, though I haven't read any problems with the 173 in your case. Try replacing the stock chip to see if that may bring her back around. Just my two cents.

Cheers and good luck,

AJ

[delatlanta1281]

I am def going to swap the batteries in the SI board soon.
Thx.

[Huff]

I still can't get my head around that the temp (gauge?)and fuel problem are related..

[AndrewBird]

The ECU will adjust fuel mixture based on temperature, so it make sense to a point. Does the temp gauge still swing, even after replacing the sensor?

I may be wrong about this, but it seems like there are two sensors on the engine, one for the gauge and one for the ECU. Someone correct me if I'm wrong. Maybe the one for the ECU is the one that is bad and you replaced the one for the gauge.

[nando]

correct, the gauge has nothing to do with the ECU. it uses a different sensor altogether. the single pin-sender is for the gauge, the two pin sensor is for the ECU.

[delatlanta1281]

Exactly.
I have replaced the blue one with a brand new part. (for the ecu 2 prong). Inspected the wiring as well. Nothing is wrong with either. I am really leaning towards the ecu at this point. I disconnected the battery for a couple of hours today and after letting the car restart and run for about half an hour I drove it and it ran fine so far. i am going to drive it tomorrow and see what happens.