RPM hesitation

[Joe Isuzu]

I now have a flowmaster muffler and I recently did the tranny job (filter,fluids). Since both, my rev'd tend to hang when I lift on the throttle, in other words, you life off the throttle and the rev's remain a little high and then drop to where you think it should. Happens on normal driving so not a case of the engine not being properly warmed up.
So, do you guys think I added too little/much tranny fluid or do you think the flowmaster has something to do with it?

[VehiGAZ]

Too much fluid, IMHO. The muffler shouldn't affect how it shifts (mine transmission didn't change its behavior when I put my Flowmaster in, FWIW).

[Joe Isuzu]

ok, thanks for answering, I'll see if anyone else chimes in with their thoughts before I start acting but if this is the culprit, I'll be a happy camper b/c then it's the easiest thing to fix!

[tom4bren]

Joe,

Is it engine braking that is keeping the RPMs up or is the engine still pulling when you let off the gas?

If it's the former, it sounds like that would be a good thing.

If it's the latter, I would think it's an engine problem: timing, Vacuum advance, sticky throttle cable...

[etlsport]

flowmaster 40 series? vcross007 called me up the other day and described a very similar problem with his vx after he installed a flowmaster 40 series muffler.. he said he was getting that problem and felt a slight loss in torque off the line

maybe pm him to find out exactly what it was

[Joe Isuzu]

honestly, I'm at work so can't tell you exactly which flowmaster series it was but I had read that thread as well so that's why I included that as a potential culprit here
and no, this is not engine braking and I agree that is a good thing, especially for your brake's sake! this is more a case of lifting on the throttle and the rev'd stay where they are and maybe 10 seconds or so later relax to where they should be, definite change
I'm hoping it's more related to either/both the muffler change and tranny job I did as it happened shortly after both were done and both were done maybe w/i a week of each other

[SilverBullet75]

Hi,
I haven't heard of those symptoms... never had that w/my Flowmaster S40 (1st VX). Nor with my Vortex (2nd VX). I'm leaning toward tranny... but not certain.

[Joe Isuzu]

thanks for responding silver bullet. If no one else has any input, I will wait until this weekend and drain a little tranny fluid to see if that does the trick. Assuming I'm on level ground and have warmed the car a little, is it a fair assumption that if I unplug the fill bolt, should the fluid be level with the opening to the point that no fluid drains out?

[Ldub]

thanks for responding silver bullet. If no one else has any input, I will wait until this weekend and drain a little tranny fluid to see if that does the trick. Assuming I'm on level ground and have warmed the car a little, is it a fair assumption that if I unplug the fill bolt, should the fluid be level with the opening to the point that no fluid drains out?

http://www.vehicross.info/gallery/data/500/fluid1.png

[Cobrajet]

I've experienced that "sticking throttle" before, and I believe it was engine related, not transmission. It did it several times on my way to work, and one time I pulled over, shut the engine off, restarted, and the idle was back to normal. No codes that I can recall, but I think the ECU was trying to compensate for some perceived emissions (O2) readings. I think it went away by itself. I would suspect a dirty MAF, sticking EGR, or O2 sensor before a tranny or muffler. You could always try a 20 minute battery disconnect to reset the computer.

[Joe Isuzu]

thanks for the thoughts cobrajet, seeing as how I just recently did the muffler and transmission work, I feel pretty comfortable that it's related to one of those two (fingers crossed)
and Ldub, thanks for your post as well. Tranny overfill seems to be the culprit here which is a relief to me, very easy to fix and I will fiddle with it over the weekend and get things back to normal
Appreciate everyone's help here!

[Joe Isuzu]

drained some fluid last night, things still aren't the way I remember it before this work (tranny job and muffler) was done, of course, that could be selective memory but it's noticeably better than it was before I drained the excess fluid
happy ending!