My 4.0 is closing on 200k and those little annoying problems keep the hood open every 4-5 months now. The last thing was the oil pressure gauge sender sprung a leak, soaking the the starter area. Some soap and water and a new sender and now this hesitation has surfaced. It seems this is constant when ever starting off from a standstill. Hot or cold makes no difference. Sometimes I get the engine warning light. Other times not. Sometimes shutting down resets the light. Other times I have to shutdown overnight.

I've checked for any air lines or hoses that may have been disconnected. Nothing to be found out of place.

The hesitation upon acceleration is caused by...... I thought it might be the fuel pressure regulator that raises the FP when the vacuum drops. Are there other parts or systems at work during this time?

 

Did you get the TPS
wet by chance?

 

x2. They really hate getting wet and I've seen so many killed with a pressure washer. Got a meter you can test it with? Pulled the code yet?

 

X3.... we all know the quality control on those things leaves a lot to be desired...so we don't need to help it along with something like that.

Keep us posted

 

Yeah the TPS prolly did get wet. Not a direct shot from the hose. I'm using an older SnapOn brick to open testing and reset the Service Engine lite. I have not seen any option to review codes on the 92. You sure codes are saved on the early 87-96 ECU's?