Checked codes. Replaced the following:

TPS sensor
ECT sensor
ACT sensor
IAC Motor
O2 sensor
Spark Plugs Motorcraft ASF42C - gapped 0.44
MSD Cap and Rotor
Fuel Filter
Air Filter
Coolant temp sensor
Water Pump
Alternator
Brakes/Tires/Alignment
3" CAT back Exhaust (CAT is empty/hogged out)
Also bumped the timing up to 12* BTDC - no pinging.

Still runs rich, strong, but rich. Not as bad as before the tune-up, but still rich. I'm getting about 12 MPG, which the previous owner said was what he got too.

Any ideas why it would still run rich. Even after advancing the timing. I tried 13-14* BTDC but got detonation on acceleration.

Any Help would be appreciated.

 

fuel pressure regulator?

is the engine and year of truck a secret?

 

I'd check the FPR, too.

 

Thanks. That's 2 for FPR. Is this a common problem with the FPR?

It's in my username - 89 460 5 SPD

 

Mine smells rich at the tail pipe, plugs are light tan or gray(that says correct mixture to me). Tail pipe was black until I replaced my air pump, now it's dark tan. My CAT broke up and blew out about a year ago before I changed the air pump. I am thinking that the air pump and the CAT work together to burn any unburned fuel before it exits tail pipe, eliminating the rich smell. Only a theory until I get a new cat though. The only codes I have are 111KOEO & 111KOER.

 

is there any other way besides adding a chip to get these Speed Density systems to run leaner?