Lean mis-fire due to coolant temp sensor??

[spiDmang]

Hey R3v,

Ive been trying to diagnose my idle issues since i bought the car 2 months ago. ive thrown a ton of replacement parts at it. I thought it was a vacuum leak, and have tried using carb cleaner to try and find the leaks, but that didnt work at all. heres a list of parts ive replaced...

- cap and rotor
- ignition coil
- spark plug wires
- spark plugs
- intake boot
- fuel pressure regulator
- fuel filter


my idle doesnt jump up and down erratically. its kind of searches between 700 rpm to 800 rpm. My dad says it sounds like its running on 5 cylinders, or as if it's cammed (super lumpy idle)...

Also, when i got the car tested for emissions, it failed due to high NOx numbers...tester said it was a lean Mis-fire??

can this idle issue be due to the coolant temp sensor, or a faulty fuel pump?

I stomp tested the bitch and i get no fault codes...

HELP!

[CW325]

when i connected my temp sensors wrong it was hard to start and the idle was wierd. make sure all the plugs on the thermostat are correct

[spiDmang]

plug positions are correct.

I just ordered a new coolant temp sensor for the car. Should be arriving shortly.

As for replacing the sensor, do any of you have any good tips to getting a socket in that cramped space???

any tips would be appreciated!

[jlevie]

Carb cleaner only works on large leaks close to the head that you can flood with fluid. There are plenty of places to have a leak that carb cleaner can't find. Have a shop run a smoke test.

[spiDmang]

what would you guys recommend going about replacing the coolant temp sensor? the space its in is so cramped i cant get a socket in there

[Medivh1984]

Speed Ref. Sensor

Assuming it's '88 or newer, have you tried checking the Speed Reference Sensor? If it's getting a bad reading it would provide bad data back to the ECU for engine Timing...if you have a Bentley book, it has a better picture of where the plug is. (under where the scanner tool connector is, near Oil Dipstick, it's the plug closer to the driver side).

According to Bentley Manuel it should have 540 +-54 Ohms Resistance between Pin 1 and 2.

Just had to replace this on my '92 E30 Vert, car sat for 2 months and would not start, finally came to this sensor and two different Ohm meters both gave no reading, but spare sensor read just fine, swapped out, and it started perfect.

[spiDmang]

Assuming it's '88 or newer, have you tried checking the Speed Reference Sensor? If it's getting a bad reading it would provide bad data back to the ECU for engine Timing...if you have a Bentley book, it has a better picture of where the plug is. (under where the scanner tool connector is, near Oil Dipstick, it's the plug closer to the driver side).

According to Bentley Manuel it should have 540 +-54 Ohms Resistance between Pin 1 and 2.

Just had to replace this on my '92 E30 Vert, car sat for 2 months and would not start, finally came to this sensor and two different Ohm meters both gave no reading, but spare sensor read just fine, swapped out, and it started perfect.

hmm not sure if thats my issue, but its a good place to just check and see if its not reading correctly.

My main concern now if trying to get my coolant temp sensor out w/ removing the fuel rail and injectors