Fuelling problems

[R5gttDJ]

All of a sudden I am having problems with fuelling posted a while ago that I was getting a slight hesitation when flooring it on boost, afr's never moved but! I was running a bit rich because im going to up the boost to 18psi from 15psi once I fit my front mount cooler

however now when I floor it and boost kicks in the afr's suddenly go lean until my aem reads nothing and the car backfires as though it is starved of fuel.

I have had a new high pressure fuel pump and filter around 6 months ago so hopefully its not that.

now I'm thinking of first changing the fpr first and if this doesn't solve it moving onto the carb

what do you guys think??

cheers

[Rob1980]

I can't really help you but others might have a better idea if you can tell them (if you know of course) how your carb is set up. I.e what size jets you have currently....

[R5gttDJ]

running 15 psi with a .9ac and 1.2 2nd stage standard venture worked fine a wee bit rich before problems

[Rob1980]

I am running 17psi with a 1.3 main and the fuelling is spot on. No FMIC.

It could be something really simple like a bit of crap lodged somewhere...

[michael tierney]

if its 15psi at the manifold then ur probably at the limits of the carb........if not......check the pipework from the carb to the reg. then get a gauge and make sure u have at least 3 psi at the carb at tickover........for starters

[R5gttDJ]

Thanks for trying to help guys

Changed the fpr and no change?
What now do you thing I should tinker with the carb?

If it was miss fireing due to a ignition fault like plugs or leads would It show lean on the afr gauge?

Cheers

[Markey Mark (BD)]

Might be worth checking the plugs to see if they are ok and the gaps are fine, if its running little rich could be them sooting up abit

Failing that might be worth checking the jets in the carb to see if they are all clear, especially the acc pump jet

[R5gttDJ]

Right mark cheers that'll be tomorrow's work!

[GTphil]

Those acc pump jets block up really easy:agree:

In the past I have taken a perfectly working carb off left it sat with no fuel in for 6 weeks or so then put it back on and bosh it fuels like a bag of spanners!

It was even kept in a clean dust free environment. :confused:

So many things to go wrong in that carb it's a wonder how they have lasted this long:laugh: Most are 20 years plus old now.

[R5gttDJ]

Took the carb off and attacked it with carb cleaner lol and all sorted now!

Cheers