1992 F-150 4X4, 302, AOD 3 speed trans, 89,000 miles. The engine runs great when cold. After about 10 – 15 minutes of driving, when the engine is at operating temp, acceleration is really poor. The truck really gets to shakin’ and sputterin’. If you step on it and get the trans to up shift, the engine will ping a little, then clear out and run smooth. I’ve tried accelerating from D instead of OD with no change. I’ve tested just about everything I can find to test using the Haynes manual. I actually bumped the timing up from the recommended 10 degrees to 12 degrees. This was done with the SPOUT connector removed of course. I get better gas mileage with it at 12. Here’s what I’ve replaced over the last year: spark plugs, wires, dist. cap and rotor, O2 sensor, trans fluid and filter, IAC sensor, TPS, ICM, coil, EGV solenoid, and several fuel filters. The engine actually runs a lot better than it did a year ago, as some of these components were faulty. However, I still haven’t been able to find the cause of the acceleration problem. All I get from the KOEO, continuous, and engine running codes is 22. According the manual that means everything checks out. I’m getting this by doing the flashing CEL method. I’m wondering if there may be codes that aren’t showing up but may be found with an actual code reader. I’ve thought about stopping by AutoZone and having them check for any codes that I may not be seeing. Another thought was that the catalytic converter might be plugged. Taking it into the shop is my last option, and I’m about there. Any thoughts or suggestions would be greatly appreciated.

 

My truck has the same problem, and I have narrowed it down to the 1st cylinder. It's either the cylinder or something wrong with the head. It's now just the matter of finding time to fix it. My suggestion would be to run a compression test, and find out what the compression is on all cylinders. Wal-mart actually sells those code readers for cheap, it works great. Good luck.

 

try disconnecting the vacuum line going to the EGR Valve. Then reset your computer by disconnecting your battery for about 15 minutes. Looks like you have tried everything else.. Good Luck.....

 

A coolant Temp sensor can cause problems before it goes bad enough to trip a code. Ive been down this road many times. At this point, I spend the money and have my cars and trucks scaned with a top of the line scanner before replaceing any sensors. Thees scaners can verify the voltage of the sensors even if they dont trip codes.
Ive found I actualy save money in the long run.

Dennis

 

I know of some bulletins on the I-6 maybe pertains to yours too. throttle body gasket change. also IAC valve replace-sticking.... just thoughts.egr is a good start because off -idle. my coil tower was pitted. I think you should take the scanner and monitor the sensors after the sensors kick in to see if something is not reading. could be as the earlier post said the coolant temp. sensor which also plays a role in fuel mixture

 

I had poor acceleration with my 94 Ranger too. Troubleshooting the emission controlls and replacing the O2 sensor and DPFE did not fix it. After many months of trying and testing, I fianally had diagnostics run by a shop. What did they find? They found that one half of the ignition module was not working! The 2.3 engine has dual plugs (one set for intake, one for exhaust) and only the exhaust ones were firing. This was just enough to keep the engine working at freeway speeds but not enough for acceleration. After confirming the problem was the module and not the coil pack, I went to AutoZone and got the OEM replacement. Popped that sucker in and now everything is smooth!