Engine runs way rich and almost dies when coolant temp sensor unplugged

[jefo]

Hey Guys,

I have been troubleshooting to see why my new hybrid turbo setup is slower than the old setup. It runs great otherwise. But I went and unplugged the coolant temp sensor to check the timing and it lugged down and almost died and poured black smoke out of the exhaust.

What can cause this? Sensors or?

[shackwrrr]

What injectors and what cal? I have seen this many times with cal's that were scaled for the injectors correctly. Under normal conditions the o2 sensor makes corrections and the driveability is ok but when you disconnect the CTS the default idle pw is used to fire the injectors. If the idle pulse width is for a smaller injector the car will run extremely rich.

[jefo]

I know it's not the cal or the injectors as I have checked the timing many times before without issue. Unless the computer has developed an issue. I checked the flywheel vs distributor alignment and the rotor is pointing at #1 at tdc, so that is fine.

[tryingbe]

What injectors and what cal?

I know it's not the cal or the injectors

Question not answered.

Could DEFINITELY be the calibration

http://www.turbo-mopar.com/forums/sh...=timing+engine

[wheming]

Good memory Harry.

The Cliff notes version is check the default engine temp under diagnostics. I think it is set wrong in some base cal versions.
I set mine to 200. Only check timing when engine is up to operating temp and cycling fan.

[jefo]

It's a boost button 3 bar cal with +40's. I have unplugged the temp sensor and checked the timing before with no issues/ richness using the same setup. I attempted to check the timing when I came back from a drive.

[OmniLuvr]

you may be having an intake temp sensor problem?

[jefo]

I just tested the charge temp sensor and it had a resistance of 9.25k ohms, which seems to check out, and the voltage in the wires going to the sensor while the car was running was just over 5 volts.

What else could cause this?

[wheming]

Did you verify that default engine temp setting in the cal?
That is exactly what caused the same situation for me.

[OmniLuvr]

also, the wiring and sensor may test out, but ive had problems with the pins in the pcm connector before, i only caught it because i was able to look at live pids on my scanner, it was an intermittent problem for me and very annoying to find.

[jefo]

No I did not as I do not have the ability to. The cal must have had the correct setup at one point, since I have checked the timing with no issues before.

[wheming]

so you don't have a flashable smec? I guess, I just thought you did. Do you have a copy of the cal file? Maybe someone can check the DefaultEngineTemp for you.

[jefo]

Kinda figured out this problem. I advanced the timing to 18* btdc and it runs great with the coolant sensor unplugged.