I just had 4.10's put in my stang and I notice that when I start my stang that it almost seems to be pulsating. It will rev high then low ... high .. low for about 3 times each and then be fine. Is this normal? Thanks in advance

 

How high will it rev? Is it just on a cold start, or every time? Because mine does what you described and i have stock gears. But it will go from 800 to 1500 to 1000 to 1500 to 800....<-- Thats normal.

 

Yeah it's on cold starts but mine didn't do that before. It would rev high then gradually get down to about 800. It would be the eqivalent of you pumpin' the gas several times.... thats how it sounds. It'll start at like 2100 (do the whole pulse thing) then drop off to like1500 (still pulsing) then get to 1000 and the pulsing stops... then it's fine. When I drive it there is nothing wrong.... no pulsing or anything like that... just sits at 1000 in neutral.

 

I know exactly what your talking about. It doesn't have anything to do with the gears I can assure you of that. My car has done this about 5 times since owning it. I am not sure why it does it but my guess is the TB is having issues and will fail at some point. It kindof goes vrr vrr vrr is that what you mean?

Richard

 

Thats exactly what I'm talking about... vrrrr - vrrrrrr - vrrrrr- vrrrrrr- Then all of a sudden it stops at 1000 and everything is normall.

 

I have noticed however that since installing my Brenspeed tune it has not happened again

Richard