I have a 94 ford bronco w/ a 5.0 HO engine. Today I was degreasing the front of the engine to see where a leak was coming from and now there is a new problem. When I let it dry off and started the engine the truck idled fine but then kicked down to about 700 rpm's and then started surging from 500-700 rpm's. When I put it in reverse w/ the brake on the truck runs like it is cammed up (but it's not). I decided to drive it around the block and the there is no throttle response and it will not downshift. I scanned the truck and found codes 121 & 124. 121-closed throttle voltage higher or lower than expected & 124-throttle position sensor voltage above normal. What can cause this? and is the sensor bad or could another sensor in the loop cause this problem? I noticed these past few days that it has been running hotter than normal but not showing on the guage and upon arriving back in my driveway it smelled extremely hot for just a 2-mile loop.

engine specs: 94-5.0/302 HO, K&N FIPK II, MSD Blaster Coil, 2.5" Flowmaster Exhaust, 1" helix throttle body spacer. All emissions sensors have been replaced in the past 2-years including throttle position sensor, idle air control valve, egr valve and sensor, fuel filter, vacuum lines are ok.

Any and all help is greatly appreciated.

 

Something get wet when you were cleaning? Getting real hot almost sounds like the timing is being retarded somehow. Pull the spout and check the timing if you can. Should be about 10-12 degrees BTDC. The surging and shifting problems could be the TPS. I've had good luck sticking a straight pin through the wire insulation and using a digital volt meter to check the TPS.

 

I found it to be moisture somewhere in the system. The humidity was crazy yesterday and it was like 105 degrees. As soon as it cooled off and the humidity went down it was fine. Thanks