Author Topic: afr problem  (Read 1831 times)

owe

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afr problem
« on: 10:37, Fri 02 October 2009 »
right wen if i put my foot down in 4th gear i get 12's @wot but if i screw it from 1st gear everything is fine until i hit about 4k in 4th gear where it runs really lean. if i back off then floor it again everythin is fine and im back at 12's anyone got any ideas?
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Ash-Lee

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« Reply #1 on: 12:29, Fri 02 October 2009 »
Sounds like the carb emptying.

What boost are running?

5teve L

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« Reply #2 on: 17:26, Fri 02 October 2009 »
What fuel pump you running ?
Also when was the fuel filter changed ?

owe

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« Reply #3 on: 20:28, Fri 02 October 2009 »
im runnin 16ps1@manifold now but it was doin it at 14psi aswell. im not to sure wot fuel pump is on it uno, is there any ways to identify it? ive got a new fuel filter here so will do that on the weekend an see how it goes. thanks for ur replys guys.
everybody needs to watch this film >>>>>endgame by alex jones

Ash-Lee

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« Reply #4 on: 22:22, Fri 02 October 2009 »
Mine fuels fine at 16PSI with the standard needle jet, i don't remember anyone else having needed a larger one for that level of boost so i'm guessing its something to do with what Steve suggested.

Rob@BYR

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« Reply #5 on: 23:14, Fri 02 October 2009 »
Fit a fuel pressure gauage and re do the test and report back... fuel pressure will allways be 4psi above taken point of ref, so carb top if its still in OE placement...

Rob@BYR

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« Reply #6 on: 23:14, Fri 02 October 2009 »
sorry 4psi above boost at all times...

5teve L

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« Reply #7 on: 10:46, Sat 03 October 2009 »
I'm thinking either blockage of fuel filter, weak fuel pump or even weak power to the fuel pump.

But don't rule out a dodgy AFR unit also.. some are known to mess about sometimes if they are wired in near 'noisey signal sources' prob nothing to do with the unit though as it would be more intermittent I think.

owe

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« Reply #8 on: 17:05, Sat 03 October 2009 »
yeh i dont think it will be the wideband, it only does at that specific time plus i feel it hesitate. think im gona get a fuel pressure gauge coz i wana get a few more psi out of it yet so wud be a handy thing to check. any suggestions of make/model f/p gauge to get?
everybody needs to watch this film >>>>>endgame by alex jones

owe

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« Reply #9 on: 21:33, Fri 16 October 2009 »
all sorted now, got a uprated fuel pump an fitted a new fuel fillter just to be on the safe side, now runnin 20psi with low 12's all the way thru every gear an its stupidly quick lol
everybody needs to watch this film >>>>>endgame by alex jones

5teve L

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« Reply #10 on: 23:21, Fri 16 October 2009 »
Cool.