FCJG15

iTrader: (18)

Okay so I have searched the web with no success and the forum as well. I am not sure how else to look it up other than ask. I have an S4 1986 GXL with a bone stock motor. The intake I am using an HKS unit and the radiator is from Koyorad. Other than that and the Racing beat 2.5" DP, presilencer, and borla dual catback the motor is untouched.

Now with that being said, I have begun driving my car a bit harder now with the slight upgrades and i am enjoying it immensely. However, between 3-3.5k RPM I hit a lag in power, what I mean is the car will momentarily stop generating power and then hit about 3.5-4k and take off. This is only under hard acceleration but happens through all gears if flat out.

My air pump is hooked up to the cat, I was told this generates back pressure to allow ports to open or something to that nature? Could this be the actuating point? Or would that not be felt?. Very confused and more curious than worried.

Any help is as always greatly appreciated! Thanks for everything

CHEERS!

lduley

iTrader: (1)

Sounds like your fighting the ole 3800 hesitation. Start off by cleaning your grounds, aaroncake has a good write up on his website, i'd link it, but its not easy on the app

satch

iTrader: (1)

I agree w/the grounding redo. Mazda suggests adding a ground to the Boost/Pressure Sensor and placing this ground to the engine. This worked for me and it has never failed to date. This is the easiest manner in tackling this problem. Sometimes though it is not a quick fix and other grounding measures are required.