okay, i thought i remembered seeing a topic similar to this one (at least the title anyways) but couldnt find it in a search. sorry if this is a repost.

so anyways, the mods in the signature below are pretty much brand new. so today is the first day ive decided to take the RPM's over 4k (mostly due to the '05 Mustang GT in the right lane). so i was cruising about 60 and dropped the gear. i think i went to fourth gear (i'm still not overly sure where ill land at rpm range with the new gear setup, so fourth was a safe shift for me), all was good until i hit 5k rpm. i couldnt get it any higher. the car started sputtering and stumbling like crazy. just couldnt get it over 5k rpm. so i decide to shift to fifth gear. all fine until it hits ~5k rpm again. went a little higher maybe, but not much. so needless to say the mustang guy just kept on going and i was sitting there a little baffled. sucks i had to find the stumble this way. so i get to the next stop light (still on the highway) and the second it hits green, i'm gone. like a bolt of lightning through first gear. rpm's went to 6k with a couple stumbles and then i hit 2nd. all over again with the 5k rpm problem.

i have all new coil, wires, plugs, injectors, fuel pump, etc... i dont have a new ignition. possibly thinking that might be part of it. could the problem be in overtightened rockers maybe? ill go back over each of them tomorrow. i'm pretty sure they shouldnt be too far off though. the rest of the rpm range is extremely smooth with no backfires/stumbles/misfires whatsoever. otherwise i might consider the opti. hell, its still a consideration i guess. any ideas? let me know. thanks.

EDIT: also forgot to mention, ive got a new as&m throttle body as well. i made no adjustments to it at all. any problems that might be caused because of this?

 

I've been having the same problems. Mine hesitates a lot from 5000 to 6000 rpm's and one time it couldnt get over 4000. Anyways i removed my IAT and i didnt have the hesitation anymore until my SES light came on a little later. So i did the resistor mod tonight but it's been raining all day and the roads are wet so i can't test it out yet. I would just unplug your IAT and see if that makes it any better, worth a shot since it costs you nothing to try it.

 

k, ill give that a try here in about 20 minutes. thanks for the idea. if it is the problem, what resistors did you use?

 

Either opti or tight rockers would be my guess.

 

hmm, ill try the IAT thing now. who knows... if its that easy, i'm all for it. if not, tomorrow ill go over all the rockers. if thats not it, then i guess ill have to go with opti. which sux.....big time...

 

To do the resistor mod all you need is to go up to radio shack and get a pack of 4.7Ohm resistors should be like a buck for a pack of 5 or so. Anyway then you just pull the IAT out and bend the resistor in the shape of a U and stick it in each of the little holeso n the plug and push it as far as you can then just bend it over to keep it from coming out. you can even use some electrical tape to keep it from coming out. You have to unplug it and test it out fast because if you wait to long the SES will come on and that's when mine started hesitating again but the resistor will trick the computer into thinking the intake air is always 57 degree's i think. Anyways i'm just doing this for the time being to see if is really going to fix my hesitation and if so i'll know i need a new sensor.

 

well, i tried the trick and no luck. wishful thinking i guess. ah well, ill get to the rockers tomorrow. hopefully that helps. if not, looks like i'm staring at an opti possibly.

to anyone else that has any ideas/suggestions, feel free to throw them in. i'm open for all ideas. thanks again guys.

EDIT: found the previous post. ill read in there and see what conclusions were made.
found here: http://web.camaross.com/forums/showt...=rockers+tight

 

probably electrical... probably wires