2.3 runs rich when cold

[Rose2300]

If its running rich like that than maybe its not getting enough air in the combustion chamber? If you rapidly let off the throttle the throttlebody closes, restricting airflow.
Idk Just Spitballin here...

 

[rrbrian222]

Also the odometer/trip stopped working so I can't check gas mileage again until I rip the dash apart.

If you need a different odometer/tripmeter I have the stock cluster out of my 95 (I swapped to a 95 exploder cluster to gain the tach). You can have it for the cost of the shipping charge. I think the odometer on it reads 182K.

There's an article in the tech library about doing an odometer gauge swap that shows how to pull the needles and still retain the speedo accuracy.

 

[fivestring]

Update...

I am still struggling with this issue. But I have come to realize the rich condition is occurring only on the short deceleration while shifting gears.

If I accelerate to 3500 rpms in first gear for example, and as I am pushing in the clutch to shift, keep my rpms around the same 3500 or so, then let the clutch out in second and accelerate, the thing runs perfect. If I allow the rpms to drop like you normally would between gears, the engine loads up in that brief second and when I accelerate in second, it is like it is running on 3 cylinders for a couple seconds, then clears up and runs normally again.

Once the engine is FULLY warmed up, it doesn't do it almost at all, but occasionally it will run 'wet' just enough that I can notice it for a second.

I am thinking leaking injectors when cool, leaking manifold when cool (intake or exhaust, not sure), or some other cause.

I have sprayed carb cleaner all around both manifolds while running cold, did not notice any rpm change.

No error codes. No cat but running both O2 sensors. This issue developed slowly after doing many tune-up things.

So, gurus, what is the problem?

 

[chilsam]

Fp regulater

could be going south on you.or bad injector.