Sox, that is not the correct sensor. You need the NTCII sensor that connects to the DME, not the on shown which goes to the temperature gauge.

It should be blue. You still should be able to test it according to the DME Test plan, similar to what Sox is describing.

Nice catch Kdjones,
You are correct I identified the wrong sensor, it is the one with the blue connector on it.
Raulg,
You will have to remove the connector by taking the clip off it.
Sox

http://forums.pelicanparts.com/uploa...1558662163.jpg
http://forums.pelicanparts.com/uploa...1558662163.jpg

Both ECT and IAT sensors should be tested at sensor AND DME connector. A lot of times you spend a lot of time and money replacing sensors and problem turns out to be crispy cracked wiring & connectors in between. By doing boith measurements and verifying that readings at both sensor and DME are identical, you can rule out wiring & connectors as issue.

Soxnail,
I was able to measure the temp sensor resistance with the engine off and it was within range.
I didn't test with the engine running as I couldn't figure out how. The intercooler pipe was off the car for access to the sensor.

I decided to check the spark plugs (3 years old?). They looked in bad shape and I replaced them.
The car runs a lot better but the hesitation is still there. A few times, the car will run fine. About 50% of the time.

Do you think it could be a weak ignition coil?

Thank you for any advice you can provide.
RG

Hi RaulG,
You can measure the sensor output at the DME connector Pin 13. Do that before you mess with ignition coil.
See chart below.

http://forums.pelicanparts.com/uploa...1563411621.jpg
Sox

Also measure IAT resistance at DME connector.

Measure intake-manifold vacuum, cold and warmed-up engine.

If you really measured 40psi, that's way, way wrong.

Does car do fast-idle when cold? If not, DME is not properly implementing cold-start cycle.

I was chasing down a similar issue on my car and found intermittent voltage at the DME, and discovered the ground wires were in bad shape. http://forums.pelicanparts.com/uploa...1563639692.jpg

http://forums.pelicanparts.com/uploa...1563639692.jpg

I also noticed when I could get the car running that the voltmeter was showing 11 volts on the dash. make sure you check your ground wires.