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BoOsTeD_RB26

By BoOsTeD_RB26,
in Engines & Forced Induction

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BoOsTeD_RB26 Experienced

BoOsTeD_RB26

Posted
Posted

Hey all,

Just of last night I have been having some problems with my car. First of all the idle has become really really rough. The car will literally "shake". Im not exactly sure what it is but it seems to be excessively rich as it struggles to stay alive.

I put new plugs in it today but they did absolutely nothing.

Could it be the AFMs?

When the car is like this, the boost gauge also "flickers" while it is in vaccum.

Any ideas?

Cheers

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Steve Grand Master

Steve

Posted
Posted

Sounds like it may be a vacuum leak.

The ecu is measuring the air that comes through the AFM, but too much air gets in, so the ecu compensates by adding more fuel as it tries to maintain idle, then it over fuels, cuts the fuel - viscious cycle.

If it is vacuum, you will notice it alot more when hot than when cold too.

My guess anyways:)

have you checked all your vacuum lines?

MRK25T Experienced

MRK25T

Posted
Posted

I may have similar problems with my car.

When I stop up a hill (this occurs when driving normaly beforehand) the revs drop really low (sometimes at this point the car stalls) and then pick themselves. This loops for about 5 seconds (at a frequenct of about 1 cycle per .5sec) and then the revs stabalize.

Background:

I have a s2 R33 gtst.

I have a blitz BOV.

My AFM maxes out at less than 250rwhp on the dyno.

Sometimes when going up a hill at about 4000rpm by engine check light flashes (indicating my AFM is maxing out - its not the quick flashing that indicates pinging).

I'm running low boost (0.6bar) when this happens.

There is a Z32AFM sitting under my bed waiting to be installed to fix my AFM problems.

Anyone know what my problem is?

Mark

Steve Grand Master

Steve

Posted
Posted

Well I am not sure if this is the prob, but does the pump have a non return vavle fitted? I have seen the non return valve taken off the top of 044 pumps to make them easier to connect.

I am sort of guessing :P, but when at idle the fuel pump will switch on and off as fuel pressure increases and decreases, just like when you turn the ignition on and dont start the car, the pump will prime then shut down. I am thinking that perhaps the pump is shutting down, and fuel may be returning back down the lines, which isnt a major problem until you are facing up a hill.

Have a look at boostmeisters low engine rpm stalling thread, goes into detail of wiring fuel pumps to be constantly on to avoid such dramas. Not sure if this is your prob, but may be:)

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