Standard R32 Gtst Problems Plz Help?

[BOOSTA]

Hey guys,

I've searched through various posts to try and find a solution but im just not sure if any of the other posts have the same problem.

I currently have a

1989 R32 gtst

Rb20det

3" hiflo cat and bee-r exhaust system (standard dump pipe)

HKS pod filter

Standard Bov

HKS spark plugs (havent changed since buying car as in good condition)

Standard Intercooler

Standard BOOST 9psi (spikes 10-11)

Since buying the car 5mnths ago it has been fine but for the last 2 weeks the car has been excessively backfiring,popping all over the place ( during gear changes, only when i come off throttle).

Its not missing during any part of the rev range but when i start the car its very lumpy, like barely wants to start running but then speeds up and idles fine.

It seems to be starting to lack power under full throttle and im abit worried about if it might be leaning out but i dont know how to check to see if it is.

Someone drove beside me the other day after following me up a hill and asked if my car was leaning out? They did say i wasnt blowing any black smoke under full throttle etc?

Im only a 2/3yr apprentice mechanic for kmart tyre and auto and I dont have the amount of $$ to get it on a dyno so was wondering if theres any way i can check stuff to see if certain things are working ok? my clutch is starting to slip alil so i have to save for that aswell so if anyone can help with any idea's or ways to help try and sort out whats going on would be greatly appreciated.

Many Thanks

Pete (BOOSTA)

[AzzurrA]

okay, you work for a kmart tyre and auto... do you have a pressure gauge at all around the workshop? if so, i would T that into the fuel line (between the pump and the regulator) and see what sort of pressures you are getting... sounds like it's possibly a fuel pump drama, might be getting towards the end of its life?

[BOOSTA]

Thanks azzurra is there anywhere in specific to T into the line? and if i do what sort of numbers should i be looking at as ok?

The fuel pump im guessing will probably be standard like the rest of the car aswell. Thanks for your input!

[AzzurrA]

to check mine, what we did was get a 'T' fitting.. on one prong we connected the gauge, to one side we connected a short length of fuel hose, and on the other side, we connected the fuel line from the pump to that (you disconnect this from the regulator, and replace it with the short piece of pipe that you just added to the T-piece)

then take it for a drive around the block, under normal driving conditions, and then under boost etc (get someone to come with you to read the gauge) and report back what you find....

from memory (don't quote me on this though, as it's only off the top of my head.... perhaps someone else can help out here) a 'healthy' figure will be around 3 bar (around 45psi) or so?

[predator]

clean out the AFM ?

Pull it off and check to see if there is a massive lot of oil in the housing there. If so, clean it off ever so carefully.

What azzura said as well...

[BOOSTA]

any idea what to use to clean the afm? any solvents? or just a rag? I dont really know too much about the skyline sensors etc?

thanks guys

Appreciate it! (pete, BOOSTA)

[predator]

There is a bit of argument over what is best..

Spray on electrical contact cleaner is probably the best bet.. or some metho with a cotton bud or something - but just be really careful as the element is pretty delicate and can be snapped off.

The AFM effects idle, and also rich/lean mixtures, and some oil from the intake sometimes build up over time, which can muck around with that.