Hey guys I have a '98 ext cab off road with the 4.6. I was wondering if any of you have ever experienced the engine " back off slightly" at like 3500 rpms at WOT. Mine does this, doesnt lose much acceleration but you can feel it. Also how do you tell what rear yourtruck has? Thanks guys.

 

3500 rpm??? I've never gotten mine anywhere near that high. As far as the rear end, you've probably got an 8.8 inch. Ratio is most likely 3.55 but maybe someone else can help you confirm for sure.

 

your drivers door sticker has the codes for your truck. You can decipher them through a link found on this sites homepage

 

sandy,

I've had my truck at 3500 plenty of times and have never noticed a backing off. Mine seems to have a little extra kick right around the 3000 to 4000 mark.

Rich

 

sandy,

I've had my truck at 3500 plenty of times and have never noticed a backing off. Mine seems to have a little extra kick right around the 3000 to 4000 mark.

Rich

 

sandy,

I've had my truck at 3500 plenty of times and have never noticed a backing off. Mine seems to have a little extra kick right around the 3000 to 4000 mark.

Rich

 

sandy,

I've had my truck at 3500 plenty of times and have never noticed a backing off. Mine seems to have a little extra kick right around the 3000 to 4000 mark.

Rich

 

not sure what happened here. anyway, sorry
Rich

 

Seems to be a lot of that quadruple posting lately

BTW I have a 4.6 in a Screw (not a 4X4) and have gone to 5000 a few times and I would have to say my truck just gets going really good at around 3000, so I don't know what the problem might be. (ps I have a Superchip program also)

 

Thanks again guys, I guess I'll have to get a chip and see if that fixes it. The truck pulls really hard its just at 3500 it stops for a split second then picks up hard again. Hard to describe sorry.

 

Thanks again guys, I guess I'll have to get a chip and see if that fixes it. The truck pulls really hard its just at 3500 it stops for a split second then picks up hard again. Hard to describe sorry.

 

What do you have for mileage?

The first thing I would do is dissconnect the battery, turn on the headlights, (apparently this is to drain any residual power) and wait at least five minuets before turning off the headlights and reconnecting. This is supposed to start the PCM without all the information that has been saved for all the miles driven. It is possible that "adaptive strategy" may be using infomation that is not condusive to a smooth running engine. A long shot? Perhaps, but free.

A chip may help, but you also make sure that it isn't a maintainence issue. Regardless, I would suggest a chip. It's a cheap way to have a better running truck.

3500rpm isn't high at all. It's actually right in the meat of the power curve. I will admit I have exceeded 3500rpm a couple times myself.

Good luck. Let us know what you find.

 

if your just cruiseing, is'nt 3500 about were our tranny starts to shift. of course if you plant your foot this idea is voided. if not your throttle positioning sensor might have a little corrosion in that area. what gear / speed are you in when you noticed it?

 

I've heard of several 4.6's that have the hickup at 3200 to 3500 rpm. Mine does it too on occasion. It happens mostly after you've driven in 'Granny' mode for a while. After a few performance starts and harder driving it goes away. I think the computer gets used to mellow driving so when you punch it, it anticipates a shift at 3000 rpm, sets itself up to change gears ,goes oops he wants to go faster and then continues to increase rpm.
Try driving like a young punk for a day and then see if it still does it.

Fritz

 

My 97 did it for years until I got a new trans. I'm not saying yours has anything wrong with it, but the converter tends to lock and unlock there. A PCM reflash will clear it up, but my factory converter was wasted. I know what you mean though, it drove me nuts! I had to go as far as riding with a black box in my diagnostic port to see what it was. I thought the fuel pump was going. You should be OK, but if you ever get the trans rebuilt go with a better quality converter. I makes a big difference.