Hesitant at low RPMs ?

[VeYzZii]

Hey fellas. This is the first time anything like this has happened to me. Ive tried searching on Ozhonda and the web, but i havent ran into a thread that explains my problem. So i was coming up a slight hill in 3rd and gave it about 70 percent throttle, the car was at about 2500 rpm, it climbed abit then sort of felt like it hesitated, and i could her something spinning from the rear. It felt like the clutch is holding and letting go and holding again then letting go and the car sort of gets into a rhythmic pull and push. Now it doesnt matter if im going flat or downhill, whenever im in low RPM range, from about 2500 to 4500,and flat it the car seems like the revs climb, but there is no push. BUT, in 1st and 2nd there is very minimal hesitation. Also when dropping down, when i say go from 4th to 3rd the car will initially slow down when i first realese the clutch, but then after a second or two, it feels like the clutch lets go and the car rolls on but the rpm still drops nicely.. Most of the symptoms lead to a faultied clutch, but the clutch isnt too old, only about 18 months, and when i do the typical clutch test of holding the break in first and slowly let go of the clutch it grips and shutters then stalls.. The car was tuned a week ago at Toda and hasnt had any problems since. Hope you guys can help.. Cheers.

[AusS2000]

Are you saying the cars motion hesitates, or the engine hesitates.

If the former, it's your clutch.

If the latter, it's your tuning. You can confirm this by removing whatever device you added to tune it and get it back to stock and see if it goes away.

[l3vnd1]

Sounds like the symptoms of a faulty MAP sensor

Try the MAP Whack or alternatively just pick up a new one.

[VeYzZii]

I thought it was something airflow related like the MAP, but when it hesitates it feels like something is spinning loose at the rear.. Or maybe its because as it hesitates it slows the wheels down enough to let them spin then hits power again making them spin..?

[tiksie]

Check timing..

[Clio]

If the revs climb but there is no 'push' in my (unqualified) opinion it is a drive train issue. My vote is clutch.

[s2kjn]

If the revs climb but there is no 'push' in my (unqualified) opinion it is a drive train issue. My vote is clutch.

If you were an auditor, the term 'unqualified opinion' means that you are close to 100% certain in what you are saying.

[s2kjn]

I would be inclined to do as AUS said above because MAP sensor problems are far different from your symptoms - such as shutting down completely while driving - has happened to me in traffic!

[VeYzZii]

Ok so i had to drive to Newcastle today and had a long time to get to know the problem. So usually the problem is at 3500RPM to 4000RPM.. Only in high gears. The Apexi meter has a 'correction' gauge, which as far as i know tells you how much the Apexi unit is actually kicking in to control Air/fuel, which also effects timing.. If i take it slow through 3500 to 4000, its fine, the correction gauge is stable at about +5.0 %.. BUT if i flat it through the same RPM range it drops and drops to about +0.5% correction.. I dont understand why it drops when i floor it, but stays at about 5.0% when i cruise it through there.. When the problem does occur, i wouldnt call it bogging out, it feels like something is holding onto my flywheel and resisting the spin.. Sometimes the revs still climb, but slowly, but most of the time it sort of just flats and stays at around the same RPM but feels like it struggles then eases, then struggles then eases again.. I can take that Apexi unit out and wire it up normally, but i rather take it down to the tuner and tell him the problem, as it may be his tuning and work is taking the piss out of me, along with 6 demerit point fine yesterday >:-|

[AusS2000]

Now that we've kinda discounted the clutch idea it might help a bit if you told which A'pexi unit you actually have. And how the tuner installed it (cut and solder or plug and play harness) and did he dyno tune.

[VeYzZii]

I have the Apexi Neo. I bought it second from a Ozhonda user. I installed the device with cut, solder and insulate. And got Toda to tune it, and also have a look over the wiring to make sure all was good. He tuned it using a dyno. It was perfect whilst tuning. No problems.

[AusS2000]

Ok, I'm familiar with this type of device. All it does is intercept the MAP signal and sends an altered signal to the ECU in the hope the ECU will react a certain way. It might say the MAP reading is a few percent lower in the hope the the ECU will respond by reducing he injector duty and hence run leaner.

I personally never had much luck with these bandaid solutions. They don't take into account atmospheric changes, how the ECU will alter timing, or how the ECU will relearn fuel trims over time. They do show a nice collection of gauges though.

[AusS2000]

Oh, and I never cut my harness. Always used a plug and play extension so I could pull it out at a moments notice.

[TODA AU]

but i rather take it down to the tuner and tell him the problem
So instead of wasting time online, why don't you just come back & got it sorted?
(My guess is there is a conflict with O2 sensor long term trim & part trottle trim value. If I'm right, the fix is quick & easy)

[AusS2000]

He's right. Adrian will look after you. Just don't rush to get there and get another ticket.

[VeYzZii]

So instead of wasting time online, why don't you just come back & got it sorted?
(My guess is there is a conflict with O2 sensor long term trim & part trottle trim value. If I'm right, the fix is quick & easy)

Cheers Adrian. I will head down soon. Just a day or two left on-site and i should get a few days off.


He's right. Adrian will look after you. Just don't rush to get there and get another ticket.

Pricks are everywhere these days. Its hard to miss a ticket. LOL. Thanks for the input and help Wayne.