Engine 1993 rich under throttle

What History may have precipitated this condition, I.e.; Recently purchase, new build.(?). Helps Prevent excess vague Data from being thrown at issue(s). Easier once you post that. A few 2D checks, for now..
Does the EEC have an aftermarket Chip?
Engine temp. have any affect, on issue?
Buy a can of CRC MAF Cleaner.
Do a quick scan of all your Wiring, Splices, Vacuum lines. If anything here is questionable- Repair/Replace it. Remove & inspect- repair & reconnect all Plug-in’s. Use Dielectric Grease.
1) If your Fuel line does not hold pressure for 5-10 minutes after Prime, Engine shutoff.. may have a leaky Injector.
2) Grounds, Engine-Chassis-CPU-Harness
3) Weak/intermittent Spark, Coil input Pri/Sec.output, Distributor: Stator-Pick up, TFI. (Any above aftermarket look very close). Spray it out clean with CRC MAF Cleaner.
4) FPR Diaphragm, induce a small Vacuum- should hold. Check for Fuel seepage into the Vacuum line. Verify no Vacuum leaks.
5) MAF Sensor: Clean it & the CAI & TB w/CRC MAF Cleaner. Pull the MAF Plug with engine running, engine should die or struggle- if not, verify all MAF Plug Pins& Connections are intact, verify Voltage/Resistance parameters are to Spec’s.
6) ECT Sensor, check with VOM. Coolant level OK and Thermostat correctly installed and functional.
7) O2 Sensors: Clean w/ Connectors tight, swap sides on reinstall, ensure connectors land on the appropriate sides.
Hopefully you’ll stumble into something with the above, be much easier with that History.
Good luck!

saleen92sc said:

I need help diagnosing a very rich condition under throttle. The car seems to run ok, but its low on power and slow to accerate RPM. I installed a AEM wideband to monitor AFR and have seen that the car idles around 14.5 but at any speed with more than 50% throttle the car goes to 11.0-11.3 AFR. I need to figure out what is causing it. Below are my specs.
1993 5.0 LX vert 139K miles AOD 3:73
K&N panel filter
Off road H-pipe
Smog pump delete
Summit 75mm MAF w/slot style meter (car runs the same on factory MAF)
fuel pressure 42psi vac off
New tune up parts, timing 12 degrees
Only codes are for the deleted smog

Thanks, John

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Eactly what are the codes?
Did you get the engine running codes?