97catintenn

Hello,

I have a 99 3/4ton 4wheel drive auto w/OD truck that has just recently started acting up. It seems to be fine up to 70mph, but at 75 the truck has some sort of surging feeling. You can feel the truck sputtering along, while it's keeping the speed up.

Listening to motor, it keeps a consistent tone to it. So I have ruled it out. My thinking is that it is something to do with the transmission. It has fresh fluid and filter in it, and I checked it again to make sure it was at the right level.

What could be causing this?

Thanks for all suggestions,
Matt

Geico266

Is the overdrive locking & unlocking? Tach needle jumping around?

OKIE99

66GTO
Member
Member # 5129

Rate Member posted July 23, 2005 02:11 PM
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If it's your TC locking & unlocking........

just fixed my 1999 with the exact same problem.
I learned the ONLY thing that time changed was corrosion. PERIOD! After wrestling with YOUR VERY PROBLEM for over a year now (I've done it all at 172,000 miles on my 1999) I FIXED THE PROBLEM the following using common sense and LOGIC.
#1. Forget a filter of any type.
#2. Forget about rewiring any wiring braids.
#3. Forget about reflashes.
#4. Forget about electrical loads

Your truck ran great for how long without the above filter additions, wire loom changes, computer reflashes or electrical loads.
Your computer and T/C worked well before WITH your electrical loads, without any filters, without computer reflashes. Use your common sense. What fixed MY truck.......drumbeat please.............was that I cleaned, to BARE SHINY METAL, 3 points. Each NEGATIVE battery post has a smaller black wire you will see goes to nearby sheetmetal. REMOVE SCREW and clean metalto BARE METAL. I took both screws and held them with pliers and held them at a wire wheel till they shined. THEN, at your PCM (on firewall behind your stock airbox) you will see a black wire, and on my PCM this black wire was on the bottom right. Remove this long screw, CLEAN PCM SURFACE where the black wire mates to screw, and of coarse CLEAN THE LONG SCREW TILL IT SHINES. With the very small voltages your PCM works with, a weak ground, CAUSED by a bad corrosive connection, will cause signals to seek or bleed to other areas. Please know electricity, like water, will search for the EASIEST ground path and thus will be affected by other high current draws (AC/Defroster mode, etc.) Everything electrical is competing for a ground, especially high current loads. Like in life the little guy loses. All this filter does is to lessen the impact or sensativity ALL CAUSED BY A WEAK GROUND. Same goes for the reflash. So goes with the bad bad wire loom that contains the alternator high amp wire. MAKES SENSE, AND IT WORKED FOR ME. All things on my truck were the same, except for weak ground points. Now those 3 points on my truck are the same as new!
What can it hurt to try ???? If you are super **** you can even run a new special wire from the PCM ground point right to your negative battery terminal. I did not have to do this as I returned my truck to like new conditions by eliminating corrosion.

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drew03

your foot slipped off the skinny pedal

97catintenn

You know, now that I read your post, I think your right on the money. I posted this problem the other night and next morning I removed my battery terminals to get them tested. The truck was also slow to start. After removing the negatives and recconnecting them, the truck started up fine. Later on that day, I got up over 70mph, closed course, of course, and the problem appaerently fixed itself.

Thanks man, you were right on the money!!