Hesitation around 4500rpms
 

Hey guys,

I am trying to help one of my buddies out, he has an 01 2v in a 99 GT convertible. After sitting for the winter, he noticed the car hesitates at exactly between 4200-4800rpms and we can't for the life of us figure out what the hell the problem is. So far he has replaced the fuel pump, and replaced the spark plugs.

Mods on the car include a BBK CAI, offroad X, catback, (no tuner) and it is not throwing any codes.

When he begins hesitating around 4500rpms, the power kicks out very similar to how it does when traction control activates. Any ideas what the heck the problem could be? Frustration level is through the roof on this thing. Could it be a coilpack? MAF?


Any help is greatly appreciated guys!

Rob

Im assuming WOT? I'd start with MAF sensor.

Just for safe measure, take off the fuel filter and blow through it. If its tough to blow through replace it. Sometimes with a dirty fuel filter when your starting to flow a lot of fuel it just cant keep up.

either way, its a 5 min job and is probably your cheapest check.

New fuel filter might help. I mean sitting for winter and all the crap just sitting in there ain't good. Sounds like a COP to me though. Does the hesitation come with a slight miss, sounding like the timing is being pulled?

sounds like a bad fuel filter to me... I don't its a COP because the car must throw a code...

Did you change the fuel filter with the fuel pump?

We didn't change the fuel filter when we changed the pump. The easiest way to describe the "miss" or "hesitation" is exactly like the sound of traction control kicking in and killing your power until it senses traction. For example, if you try peeling out from a stop sign and the engine cuts power for 3-5 seconds, that is the exact sound between 4300-5000rpms. Its noticeable enough that you can literally hear it in the exhaust.

F me, actually WE DID change the fuel filter already.

sounds like a COP or maybe the MAF. Unplug the battery for a bit and see if anything changes.

run a boost leak test.