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Stumble at high revs

Posted: Tue Oct 07, 2008 7:08 pm
by ReeceZ
Hi guys, need an assist on this. The car stumbles at hi revs but I don't get it that often. Not getting white smoke from the exhaust so the turbo seems fine. Changed spark plugs today and tightened pipes, but it still happen. It doesnt seem to occur when i'm in 4th (for example) and accelarating right through the gear. Occured when I dropped from 4 to 3 tho. My Walbro fuel pump should arrive soon so i'll change that out. Has anyone experienced something like this before? Is there anything else I can look at.

Posted: Tue Oct 07, 2008 8:12 pm
by ReeceZ
ok, jusst went for short drive, found that if you accelarate gradually thru any gear, its fine. But once u race thru 1st then get to 2nd at about 5000rpm, it stumbles. Same story with third and fourth, seems as though something or the other can't keep up.

Posted: Tue Oct 07, 2008 8:20 pm
by rat
Fuel pump i think, fit it and see what happens

Posted: Tue Oct 07, 2008 8:20 pm
by poizen
myn does the same as soon as i get 5000 and 0.8bar boost

Posted: Tue Oct 07, 2008 8:21 pm
by ReeceZ
Your fuel pump installed yet poizen?

Posted: Tue Oct 07, 2008 8:28 pm
by poizen
no hasnt left the states yet :(

Posted: Tue Oct 07, 2008 8:34 pm
by ReeceZ
I bought the same as you did, cost me $99, still waiting :roll:

Posted: Tue Oct 07, 2008 8:46 pm
by poizen
same cost $99 = free shiping jus waiting i keep emailing da oke but no reply

Posted: Tue Oct 07, 2008 9:38 pm
by veecee
race through gears, high revs...

rev limiter???

Posted: Tue Oct 07, 2008 10:36 pm
by poizen
veecee wrote:race through gears, high revs...

rev limiter???
nope vc not that it like you got fuel line full of fuel then a air pocket so it skips just till there furl again and then takes off am i right reecez

Posted: Wed Oct 08, 2008 7:59 am
by ReeceZ
Yup, exactly whats happening, if i drop the hammer in 1st car will rev happy to 7000, after shifting and its still in high revs thats when it stumbles, just hope its the fuel pump. gona park it off until i get the FP, don't wana do any internal damage.

Posted: Wed Oct 08, 2008 8:03 am
by HancoB
Mine did that for a while and then it just sorted itself out.

Pull strong now without doing that.

Mine only did it on cold mornings and at night when it was cold.

I suspect It has to do with the AF ratio, since I was boosting higher and thus my AFM gave a wrong reading or so and to much air and not enough fuel.

But ja its sorted now!

Posted: Wed Oct 08, 2008 10:46 am
by ReeceZ
its weird it will do it sometimes, but i getting tired of the whiplash from the stumble :P

Posted: Wed Oct 08, 2008 12:58 pm
by Trance101
I had a similar thing but it only happened when I was relatievely low on fuel. It only happens when you change to 2nd or 3rd in high revs. The walbro seemed to sort it out.

Posted: Thu Oct 09, 2008 9:08 am
by ReeceZ
@ Trance after ur conversions done I think ur gona need dual pumps :lol: