2000 xls hesitating\skipping

[onlyworth10]

Just put a new Valve body on it this week and all was well, till today I was coming home and started to climb the mountain I live on and it started hesitating\skipping, also felt as if it was trying to cut out on me..Im about ready to burn it.. Anyone have any ideas? also when it does start skipping if you put your foot in it all is well and climbs the mtn easily.. It does have the 5r55e, and the ohv v6... Thanks for your help

 

[onlyworth10]

possible fuel filter?????????????

 

[2000StreetRod]

Replace fuel filter & clean MAF sensor

If it's been more than 30,000 miles since you replaced your fuel filter I would change it even if it's not the cause of your problem. It might prevent premature fuel pump failure. I always add a bottle of fuel injector cleaner after replacing the fuel filter.

Is the CEL illuminated and if so what are the diagnostic trouble codes?

Have you cleaned the MAF sensor recently? A dirty MAF sensor results in a rich mixture at slow engine speeds and a lean mixture at fast engine speeds. The higher the altitude the more important a clean MAF sensor.

 

[onlyworth10]

No engine lights, and I will change the fuel filter today with a bottle of Lucas fuel injector cleaner

 

[onlyworth10]

Changed the fuel filter and it was really dirty, It leaked almost black fuel out of it, but Im still having the skipping hesitating symptom, There are no CEL on.. Im stumped....

 

[ERUSH97XLT]

I'm with StreetRod: Check your MAF. Even though you don't have a CEL, it might be dirty or malfunctioning at altitude. Get some MAF cleaner from your favorite auto parts store.

Besides that, there is A TON of things that can cause a skip like what you mention. Since it seems to be remedied by flooring it, I'm guessing an air-fuel issue. Fuel filter change with Lucas additive is always a good idea. I would check your fuel pressure, too, it could be a weak regulator.

These are the obvious things. You really can't tell what the engine is thinking without a computer diagnostic scanner. You can change and test things 'til your blue in the face, but you won't know for sure unless your computer is read under those conditions.

ERUSH