Engine running rich

[84300T]

I bought an 84 300ZX turbo w/54000 orig miles. It is running extremely rich to the point of flooding the engine. From the analysis that I have done the computer seems to think that the engine is running extrmely cool, therefore feeding more gas into the engine. The temp sending unit is working fine. I bought a used computer off of e-bay, but that didn't change anything. The disconnect at the temp sending unit grounds out on both sides (I think it should only ground out on 1 side) with the wiring harness connected to the computer. I thought that maybe there was a short somewhere, but if I disconnect the harness from the computer the 1 side is no longer grounded out. Again this is on both the original computer and the replacement computer with the same model #.

Can anybody Help??

[evildky]

welcome to nico!you say the cmputer thinks theengine is cold, you have consult or similar to see what the computer is seeing?

you are correct that a bad or disconnected CHTS will cause the engine to run excessively rich, if the ecu sees cold and you've eliminated the ecu and the sensor, that means the issue is int he harness, it doesn't have to be shorted it can smply be disconnected and cause the ecu tot hik it's cold

[Perrenial Badass]

I'd start with a new CHTS and it's subharness. Might be a good time to do the 60K mile service, since you are near 60k miles and will have it down anyway.

http://www.courtesyparts.com/h....htmlh ... /b...=2317&

You can get all of that from Autozone, Advance, or what have you. Well... most of it at least.

I'd put my money on it being the CHTS, how's the cold start idle?

[84300T]

It's running too rich to idle. You can literally watch the fuel gauge drop! When I can finally get it running, it won't get over about 1400 RPM before it floods out.Just a note, I bought it from a friend whose father in-law took the valve covers off because the lifters were knocking (and never finished the job). I replaced the lifters and put it all back together. It was running fine before he took it apart.

Thanks for your comments and suggestions.

[84300T]

No, I don't have consult or anything else. I took it to a small shop that came to that conclusion, but couldn't get past that.

Also I mentioned that I put it back together and got it running, and got it to pass emissions (barely). Now it wouldn't even come close to passing emissions!

[evildky]

the chts is located itn eh front of the drivers side head, the wires taht lead to it go near the top front conrer fo the drivers valve cover, make sure the wire isn't pinched, it could also in theory get pinched betweent he plenum ad the lower intake, but replacing the chts woulod eb a good next step