Running Very rich after new Head install

#1

Just had the head refreshed due to some bent exhaust valves now the A/F meter is showing about 10.3 at idle. Will it lean out after it gets some miles on it or should I do something like tinker with the MAF?

What could be the reason?

#2

hi
check your coolant sensor for the ecu

#3

Check it how? Not sure I understand what your saying here.
Sorry.

#4

the sensor is on top of the thermostat housing
you should have two sensor there one for the gauge and for there ecu
look for the lite blue in color sensor.
they often go bad and will cause the engine to run rich.
its a easy fix just replace it and see what happens

#5

Bentley has the test protocol. Test it at the DME end of the engine harness, that’ll tell you if the DME sees it. That could be the whole problem.

You getting a CEL? If so do a stomp test. Google it if that’s new info.

Engine seems to idle ok otherwise?

Mixture odd only at idle or also at higher rpm?

#6

I will test it but it worked fine when I took the t-stat housing off the head, I will check the harness plug to make sure that its plugged in good as I did unplug it. Idle is fine and it stays rich up to 3k, but I think the neighbors would have an issue with me taking it to 6. I will be at the season opener at Sonoma this weekend and will be able to investigate further. I dont have that little warning box in my car anymore so I dont know if im getting a CEL. But if you can think of anything else that may be an issue let me know, I will have interweb access.

Thanks for the help!

#7

This sorted itself out at the track this weekend after I adjusted some valves of course! Thanks for the help