Author Topic: Hesitation on and over 3k rpm (video included)  (Read 1667 times)

s3irios

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Hesitation on and over 3k rpm (video included)
« on: 01:01, Sun 20 November 2011 »
Hello again i'm starting a new topic since i got new data and more organised now.

As it was my problem persists. Under load at the 3k rpm and over i feel car not wanting to rev, holding back a lot. If i push accelerator full open, it pops from the engine somewhere and doesn't spool up. I don't have the valve that the genuine r5gtt has on the hose that goes from intercooler to carb, that bangs on overboost so this isn't it.

Also i have the choque cable removed and the choque on the carb tighten with a tire-up so it doesn't open accidentally. The rpm on idle are set at 800 rpm and they were steady.

BUT the rpms when cold AND hot are at 1200 with no apparent reason. Sometimes and on the road while stopping in a light or something, the rpm would drop to the normal 800 and when there the car has NO hesitation or holding back at 3k under load , it revs normallly.
If the car is mis-operating on idle at 1200 rpm  the hesitation at 3k under load appears...
Prior to these problems i had just installed new spark plugs and had the valves adjusted. Nothing else.Then the next day these problems appeared or at least made themselves more apparent (the problem may have been there some days before too but i can't remember)
This is the general problem, now i'm going to write what i've done to the car while trying to solve the problem.


*Changed dizzy cap
*Changed rotor arm inside dizzy
*Checked all hoses and pipes for any air leaks.None found
* Removed whole carb, turned to bits and cleaned thoroughly with carb cleaner.Nothing too serious dirt wise, but i insisted on triangle part of the carb just incase.Reinstalled all fine.
* Mixture screw is a-ok rubber ring on it fine too.
* Put a smear of sealant on the top of the inlet manifold only not on carb side, as i read at posts about warped manifolds. There was a leak there which got fixed.
* Checked by sight the spark cables nothing there. Reinstalled them just incase.
* I also found possible mega leak at the inlet manifold on the connection with the head. Found this while i was checking if the nuts of the manifold were tight, and gues what they weren't. Tightened them as much as i could. THe leak fixed a bit, previously the mis-idle was at 1500 rpm now stays at 1200 rpm as i mention above)

Nothing changed on the main problem. It's still there, it scarsely stops and hav the right idle at 800 and NO hesitation, then it magically reappears next time i drive the car.

I promised a video so here it is.

It's after a 25km trip, warm engine FULL hesitation on the 3k mark all the way. I'm stopped outside my home and on IDLE only. I'm NOT pressing the accelerator at all so:
1) why idle at 1200 when i've set it at 800? Maybe the renix broken? Or the manifold still elaks that much?
2) why these fluctuations on the revs, up and down?
3) LOL i just learnt that a faulty alternator can be the reason for hesitation under load! Is this a case on the r5?
[youtube:3jhwsqgc]http://www.youtube.com/watch?v=NoCrNHOxqTk[/youtube:3jhwsqgc]

s3irios

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Re: Hesitation on and over 3k rpm (video included)
« Reply #1 on: 00:09, Sat 18 February 2012 »
OK so, for anyone having same issues, it's the head gasket and/or head needing clean and skim.Also changed inlet gasket too (it's a set)
After doing it on monday car is super fine now, no hesitation just a bit at sometimes on random moments but i blame the poor quality gas. Car spools great and moar power than evah!

Have fun all.