I recently pulled the S out of storage and just before I put it in storage it was stumbling during WOT but only in the higher RPM range. So it still is doing the same thing now that it's out of storage. However, when I go a little lighter on the pedal but still roll on the throttle up through the RPM range it doesn't stumble.

What do you think?
- Fuel filter replacement?
- Fuel pump?
- Throttle body service?
- Other?

The car is a year 2000 with 51,000 miles. Its never had any fuel system service.

Thanks,

ExTex

 

why not try fuel injector cleaner first ..

 

spark plugs too... could be a misfire in the high ranges

 

Map sensor?

 

I'd start with the fuel filter?
if you think about it, it is designed to clog if you get a lot of dirt.

 

I agree with cubby and would start with the map whack before strying anything else...

-at idle
-lightly blip the throttle at the TB, just a few hundred RPMs up and down
-while blipping the throttle, whack the map sensor with the rubber end of a screw driver several times. Not too hard, but not too soft either.

I bet that fixes the issue.

 

Fuel filter is in he gas tank . It is part of the pump assembly . I have never seen this as a problem before . I doubt it is the problem ..

Most of the fuels out there have cleaners in them , not really needed anymore .

I would swap the plugs first . Not sure if you have ever check the plugs before . But early years have had plug problems ( Torqued incorrectly ) when they start backing out can cause misfire . I have seen them loosen enough that they will backout fully, and the compression will cause the plug to wipe out the coil pack . Most of us check them regularly .

 

Possibility and does not cost anything

 

Ahh the old map whack trick, ill wager that fixes the problem

 

I was reading that another good fix for the MAP was to remove it...and blow air through the air hole leading to the senor on the TB,.