4k-5k RPM hesitation

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4k-5k RPM hesitation

Postby gpmarzan » Tue Jan 25, 2011 9:10 pm

Whats up guys. I havent been here in a while as I sold my alltrac to bloodmoney (Chris) and bought a 92 MR2T.
My question pertains to the deuce. Having the same good ol 3sgte, I figure you guys can help me out.

In short, at WOT the car seems to hesitate at around 4k to 5k like timing is being pulled. Once it passes 5k, you can feel the power come back, starting to pull hard again. Doesnt matter if the car is set at low boost, 9psi, or high boost at 15psi- its the same condition. So far here are the things I have done and what the car has:

-Ebay 3" downpipe (came with the car)
-3" exhaust system
-50 trim compressor ct26 turbo
-upgrade side mount intercooler
-checked for boost leak- none found but will recheck again
-replaced ignition coil- no change
-checked static timing- appears ok but i will double check
-checked dynamic timing- set at 10deg btc
-replaced TPS and adjusted to spec- no change
-fixed clogged egr system
-checked T-VIS- working properly
-new plugs (bkr7e)
-new plug wires, cap, and rotor
-new O2 sensor
-compression is good

I cant hook up my wideband as the bung on the ebay downpipe is in a wrong location making the sensor contact coolant pipe. Only 3 things I could think of now is the AFM, ECU or the timing might be off. What do you guys think?
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Re: 4k-5k RPM hesitation

Postby alltracst185 » Tue Jan 25, 2011 9:15 pm

Plugs properly gapped?
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Re: 4k-5k RPM hesitation

Postby gpmarzan » Tue Jan 25, 2011 9:23 pm

alltracst185 wrote:Plugs properly gapped?


yes...set at .028
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Re: 4k-5k RPM hesitation

Postby Grey_Matter » Wed Jan 26, 2011 11:03 am

im reaching...but hows your o2s?
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Re: 4k-5k RPM hesitation

Postby 88st165 » Wed Jan 26, 2011 11:31 am

Does it do the same thing at part throttle like around 3/4?
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Re: 4k-5k RPM hesitation

Postby gpmarzan » Wed Jan 26, 2011 3:13 pm

88st165 wrote:Does it do the same thing at part throttle like around 3/4?

Now that you have mentioned this...NO it does not do it when at 3/4 throttle or anywhere below WOT to that matter. I know my alltrac has this "faster at 3/4 throttle" issue but it wasnt like this where it hesitates only at that certain RPM range. Any thoughts?
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Re: 4k-5k RPM hesitation

Postby gpmarzan » Thu Jan 27, 2011 4:03 pm

No one? Im leaning to either the AFM or maybe knock respose.
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Re: 4k-5k RPM hesitation

Postby 88st165 » Thu Jan 27, 2011 11:45 pm

Yea I think knock is the culprit. My car used to do the same with the stock 165 intercooler and 15psi. I added WI and the phenomenon went away whenever the WI was activated. Came back when it was off.
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Re: 4k-5k RPM hesitation

Postby gpmarzan » Fri Jan 28, 2011 12:33 am

88st165 wrote:Yea I think knock is the culprit. My car used to do the same with the stock 165 intercooler and 15psi. I added WI and the phenomenon went away whenever the WI was activated. Came back when it was off.

Hmm. Although it does it even when at low boost (around 9psi)
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Re: 4k-5k RPM hesitation

Postby Simba » Fri Jan 28, 2011 11:22 pm

Probably AFM or cam timing. If you're getting into enough knock to feel timing come out at 9psi and relatively low revs, something very weird is going on.

The ECU will not dump timing back in as quickly as you're describing, either.

Lots of fast, loud things.
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Re: 4k-5k RPM hesitation

Postby McKenzieJr18 » Sun Jan 30, 2011 11:44 pm

try swaping the coil
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Re: 4k-5k RPM hesitation

Postby gpmarzan » Mon Jan 31, 2011 1:44 am

McKenzieJr18 wrote:try swaping the coil

Ive done that..no change
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Re: 4k-5k RPM hesitation

Postby Mafix » Mon Jan 31, 2011 4:24 pm

have you check the fuel pressure? and the regulator? similar issues with avi's 165 and the culprit was the regulator
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Re: 4k-5k RPM hesitation

Postby gpmarzan » Tue Feb 01, 2011 9:00 am

Mafix wrote:have you check the fuel pressure? and the regulator? similar issues with avi's 165 and the culprit was the regulator

I will def check that out.
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Re: 4k-5k RPM hesitation

Postby bloodMoney » Tue Feb 01, 2011 5:45 pm

I've got a generic FPR if you want it Patrick. I can't remember if it has a gauge on it, but if you want it, let me know.
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