G40 fuelling problems?

electricpanda · January 17, 2012, 07:35:36 AM

Hi all,

I've recently bought a G of a friend of mine, he seems to think this issue is caused by the map but I just want a second opinion before I splash out on a new map!

Basically, if I keep at low revs and light throttle it drives fine. If I drive hard and keep it over 2500 it drives fine. The problem is after using full throttle or high revs, once you try cruise at say 2000rpm in 5th is judders and cuts constantly. If I pull over, turn the car off and on then it's fine, until I open it up again.

Any help would be appreciated, I've emailed PPP also.

If it helps im running 65mm pulley, cammed, toothed belt, 250cc, fmic, full engine back system etc.

Thanks a lot.

hayesey · January 17, 2012, 09:10:57 AM

what map does it have in it?

electricpanda · January 17, 2012, 09:15:56 AM

I'll try find out exactly what chip it has, I only know its chipped and not custom.

electricpanda · January 17, 2012, 11:27:27 AM

Just spoke to him, It's a PPP chip.

hayesey · January 17, 2012, 11:29:25 AM

presume it's one to suit 250cc injectors?

also, do you know the spec of the cam that's installed?

electricpanda · January 17, 2012, 12:45:46 PM

Im waiting for the chip code, it's a Newman Fast road cam.

Do you think this problem is the chip/map?

Thanks for your help.

hayesey · January 17, 2012, 12:54:09 PM

but what spec is the cam? is it suitable for a g40? "fast road" doesn't mean anything. you'll need to specs for (at least) the duration of the cam to know if it's suitable.

If the chip is a suitable one for 250cc injectors then I doubt it's that unless it is damaged. see what PPP come back with

electricpanda · January 17, 2012, 01:12:20 PM

Ah ok, it's 264/268.

hayesey · January 17, 2012, 01:18:21 PM

right ok, that's not really suitable for a g40 then,. that's a GT cam. You want to swap that for a standard G40 cam. Even if it's not the cause of this issue it'll be causing a loss of power.

electricpanda · January 17, 2012, 02:25:50 PM

Really? I didnt know that.

I have the original g40 cam, is it actually worth the effort of fitting? Or is it only worth it if I buy a proper uprated g40 one?

Thanks again, appreciate this.

hayesey · January 17, 2012, 03:32:29 PM

I'd just put the standard cam back in. There's not much gain to be had from fitting a different cam to a g40 engine when it's using the g40 supercharger. And people generally go for a 256/272 or thereabouts cam.

electricpanda · January 17, 2012, 03:40:44 PM

Thanks mate. It is on a r1 glader so no fancy eaton or turbo!

Gonna give PPP a call after work.

packers · January 17, 2012, 06:24:38 PM

Hi had a similar problem that turned out to be bad conection to knock sensor.it too cleared after ignition was turned off and back on.

electricpanda · January 17, 2012, 06:35:27 PM

Really? I'll try that first then.

Thanks

Andy · January 17, 2012, 06:37:02 PM

There's something wrong with your email, our replies to you just bounce.

Which one of our chips is it? (If you're not sure, tell me who you bought the car from and I'll look it up).
What's your full engine specification?
When did the running problem start?

It sounds like a much more fundamental problem than the chip. I also have no record of selling a chip to someone with a 264/268 cam in a G-ladered G40, so I assume that the engine spec has been changed since the chip was fitted?