OK, so as I mentioned a while back I bought a 2005 Sahara (HDJ100) with low miles. Full intentions of running it on Bio.

I finally took the plunge and swapped the filter assembly (cav filter housing, big glass bowl) and my walbro pump off the the old HZJ105.

I posted some info on the LCOOL site (there is a lot of good info on that forum by the way) about the intake clagged up - summarised thus:

took intake apart to fit EGR, couldn't believe the caked on crud. got more than a cupful of crap off the cylinder walls - reckon it was prob 6mm thick for the whole assembly. put it back together coupled with the walbro pump and new filter, pulled like a schoolboy. very impressed with the extra punch. great engine and gearbox combo.

THEN next week when the tanks got low, I filled her up with the special sauce. D I S S A P O I N T I N G.

it lost all its punch and was back to a reasonable ho hum turbo vehicle. Well I got busy for the week with work and figured it was probably just a kinked hose or something near the push pump, deal with it on the weekend. just a fuel restriction i reasoned.

yesterday (Sunday) I had some spare time so I got to looking and thinking. a couple of quite beers sitting on a milk crate looking at the car with its bonnet up. realised that it had something to do with the pump needing more fuel as the fuel hoses are half inch internal. (1HZ was 10mm and the WLT 8mm) worried it might be the Walbro restricting it, but in reality, i thought it more likely to be the filter. I run Sakura filters on both the 1HZ and WLT (Mazda B2500) and they have never been a problem. But this pump needs more fuel, more than double the Mazda and a lot more than the 1hz.

I didn't have the balls to bypass the filter completely. I did some research and found an old post from Fitian saying that the fleetguard FF167A had a much higher fuel flow than the Delphi 269 etc. I did some of my own sniffing around and came to the same conclusion.

Well, i sent the missus down to Brisbane air cleaner services and picked up a FF167A to try. $6 or so. I put in in tonight and VIOLA!! I got my Mojo back baby!! Yeah Baby! (unashamed rip off of My old mate Austin Danger Powers).

Just goes to show the importance of the right filter. remarkable difference.

Closing note - if you feel your engine isnt performing as well as it could, consider a filter upgrade. Whilst it ran beautifully on Dino, it didnt on Bio (I guess the viscosity increase is to blame). now its the middle of a Queensland summer here, so in winter it would be even worse. I will keep an eye on it during the cooler months to see what happens.