Polo GT - Overfuelling and smoking

[m4tt]

My Polo is a track car project and currently SORN hence only gets started about 2 or 3 times per month. I let it warm up fully then drive up and down the drive and then tuck it away.

Today when I revved it, it seemed to be overfueling with slight smoking. It is fine at idle (no smoke etc) but there is the faintest hint of a misfire, but may just be a rattle from the bottom end. The only thing that has changed since last time I moved it is I replaced the standard air filter with a K&N one.

Anyone with any bright ideas?

Cheers

Matt

[BoraBora]

ste stuck in fuel injector ?, just throwing em out here

[m4tt]

Whats the best way to clean them? Changing fuel filter is on list of things to do.

[aka_kerrly]

I guess you are refering to a 86c polo with the 3F 1.3 multi point engine as opposed to a more recent GT.

check for condensation in the electrical system eg dizzy, HT leads, inlet piping, perhaps whip the spark plugs out and see what condition they are in- ie wet/dry brown/black. Remove the breather hose from the back of the block and make sure its clear and not blocked.

also inless you have a heat shield and a cold air feed ditch the cone filter. My old GT made 4hp more by ditching the K&N cone and replacing it with the standard box with holes drilled down the WING side and a K&N panel filter. also consider upgrading to a mk2 Golf 8v AFM and inlet pipes combined with a ported/de wedged throttle body will give good gains - note the 8v Digi AFM will need setting up to run the 1.3 otherwise it over fuels like a beasty. Consider a PoloAce chip to from Polo3.co.uk , 6hp+4lbs but much smoother mid range and raised rev limited which is useful when you start getting a bit carried away in 2nd an 3rd....

you can achieve 100hp from a GT lump and with the gearing they can be surprisingly pokey little things.
Dave

[m4tt]

Dave, thanks for lengthy response that is superb! When i said filter I meant K&N in standard drilled box. So no need to change there. Will check ignition parts for damp. Will probs tax it for the bank holiday and give it an italian tune up.

I have a poloace chip on the list of things to do. This weekend is fitting g40 inlet and de-wedge throttle body.

The crankcase breather pipe is split and has been duck taped up, so maybe that isn't helping. Was thinking of putting a small filter on the tube and then blanking the part that goes direct into throttle body, any issues with doing that?

Also are there any gains other than weight saving by removing the carbon canister?

Thanks for help so far.

[aka_kerrly]

m4tt said:

Dave, thanks for lengthy response that is superb! When i said filter I meant K&N in standard drilled box. So no need to change there. Will check ignition parts for damp. Will probs tax it for the bank holiday and give it an italian tune up.

I have a poloace chip on the list of things to do. This weekend is fitting g40 inlet and de-wedge throttle body.

The crankcase breather pipe is split and has been duck taped up, so maybe that isn't helping. Was thinking of putting a small filter on the tube and then blanking the part that goes direct into throttle body, any issues with doing that?

Also are there any gains other than weight saving by removing the carbon canister?

Thanks for help so far.

Hello,

that is good news about the filter, so have you drilled holes down the wingside and do you have a cold air feed from behind the grill straight into the airbox? These were available from the factory on GTs but not all have them these days.

The dewedged throttle body is a good choice but the inlet manifold isnt required. You will find that G40 owners upgrade to GT inlets as they are less restrictive at higher revs at the expense of some low down torque due to having wider diametre bore.

It will definately be worth getting a new crankcase pipe and routing it into a catch tank - i had a small fruit juice bottle cable tied under the intake pipe and yes i blocked off the hole in the inlet otherwise you will be getting air in/out of the system that has bypassed the Air flow metre so it will run crap.

You can remove the carbon canister - probably isnt doing anything now anyway other than being clogged up.

Other mods which dont cost silly amounts that all help are a 4 branch manifold (ashley is circa £100 or less) a decat (£2-30) so these combined with your polo ace chip and throttle body you should be heading beyond 85hp, mine ran 88 with exhaust/air filter/polo ace/dewedged throttle.
A uprated cam makes a massive difference, i had a schrick 268* and that was enough to push mine up to 103hp after having timing reset and make full use of the 7500rpm limiter - even in 5th ;-)

In all by buying second hand and selling the standard parts i spent not a lot over £300 to get 25hp on a 1.3NA - not bad really.

As for weight, back seats, sound deadening, carpets, parcel shelf supports, boot lining, rear wiper, door cards and headlining can help remove a fair bit of weight. A guy i know running a stripped out G40 tipped scales at under 700kgs and his intercooler, charger an pipework must weigh 50Kgs so being conservative with 85hp an 700kgs you are looking at nearly 120BHP per tonne, low 16s 1/4m.

Head over to Polo3.co.uk for some more info.

Dave

Dave