Rb20 Gtst Fuel Issues?

[rotort]

RB20det, idles perfect free revs fine, drives fine below 2000rpm ish, as soon as any positive boost pressure it wont rev, tuebo spools like crazy but engine cant process the air, pretty convinced it not enough fuel,

have checked fuel pressure, has 30psi on key on not running, with same 30psi on idle with reg vacuum line off, as to factory settings

Have checked pump, has 12v all the time, i thought it would have 6 and 12v but its got 12 after prime on ignition on.

doesnt appear to be any air leak, air flow sensor is connected, if it wasnt it wouldnt run anyway.

timing is perfect, 15 dbtdc

plugs are deffinitly reading lean! but not to bad

tps is adjusted and reading .59v and 4.35v on WOT, couldnt get it any better

im thinking its the fuel pump gonna chuck a walbro in it as was going to any way, and a permanent fuel pressure gave.

any one got any ideas for me, i have a spare ignition module and CAS so can change those as well.

its odd tho because fre reving at as low s 1500 rpm it starts to spool to boost, seems like there is excesive load on something,

[Amec]

best way to eliminate boost leak is using compressed air into the intake. boost leaks are never apparent. there are just too many places where boost can leak from.

[rotort]

hey pete so your saying with throttle body closed put the compressor into the intake and see if air escapes?

will give i a go

thanks

[QWK32]

how did you check your timing? lack of power and turbo spooling up at low rpm can be the timing is retarded.

[rotort]

timing with a timing light, 15d btdc

Im sure theres no air leaks, and boost gauge reads from plenum, reading 8psi, so its deffinitly getting the air

Edited September 9, 2008 by rotort

[Amec]

hey pete so your saying with throttle body closed put the compressor into the intake and see if air escapes?

will give i a go

thanks

yes but you will need a special device to bung up the intake with a bicycle valve, should be a DIY article here somewhere on how to make a boost leak tester.

[rotort]

boost leak caome out ok, blocked the intake, used shroeder valve to pump 7.5 psi of pressure into system, no leaks other than dipstick

no question what fuel pressure should a rb0 det run on full load?

[blind_elk]

30 psi fuel pressure is a bit low, from memory - more like 39.

How did you check timing - some timing lights give an incorrect reading. Safest is to use an old-school plug lead between coil and plug, then do old-school timing.

[QWK32]

a few of the timing lights i've used, when you put the inductive pickup on the black loop wire at the ignitor gives a double reading. so when it shows 30d BTDC its really 15d BTDC.

[rotort]

so what are you saying, my 15 d btdt might be 7.5?

[QWK32]

could be. but i cant say that for sure because i haven't seen your timing light operate, or where you hooked up the inductive pickup.

on the cas, what is the position in relation to the slots of the three bolts. are they about in the middle, maybe a bit to the right in the slot? also have you had the cas off recently?

[rotort]

yes cas has been off recenlty just timing belt done, i think the timing is out 1 tooth because its near full adjust on cas to be on 15d tdc can restard more and omly advance to about 10d. so ye its off center, and es im using the inductive feed for the timing light