Thread: Fouling plugs.... Help

It could be one of a few things. Black means overfueling, were the plugs wet when you pulled them after driving on Petrol?

Leaking injectors can do this as the drip fuel after they are supposed to be closed after firing.

A faulty MAF can also over rich your fuel, as the LPG system wouldn't use the MAF it will not shop up on LPG running.
Give the IAC (Stepper) a good clean also with solvent, I doubt it is your problem though.

You could pull the injector and see if they are ok at the injecting end. I had the ends on mine disappear on a couple as I always ran on LPG and did not switch to petrol from time to time as recommended. The pintal and screen was missing so on petrol those injectors were just dropping a load out but not correctly
cheers, Mario

Hay mate,
The injectors are 5 months old, brand new ones (yep I knew a Guy), yep defiantly over fueling. I thought it may be the afm, but I'm running a 3.9 hotwire and a 4.6 bottom end.

I'm assuming I need a exhaust gas analyser to retune it soo it won't lean out.

I was thinking of buying a brand new one. Do they make brand new factory ones, I'm reading bad reports about buying one off the net... eBay especially.

I've read that you can test. The afm by testing the ohms on the two end wires, and if it's hitting @@@ (anyone know what the readings should be, all I can find is a %40 figure which doesn't help much) it's bad, cos the rovergauge is telling nothing wrong.

I've tried cleaning the stepper motor, leaks.

Cheers Nat

Have you checked the ECU temp sensor? That's the temp sensor behind the thermostat housing with a 2 wire plug like an injector plug. It should read around 300 ohms with a hot engine.

Also check that the hose for the fuel pressure regulator hasn't fallen off the vac port on the back of the manifold. It will run very rich with this hose off.