Why the 82.5 wouldn't run at Sandown

[Mat Francis]

As a few of you saw, with a working pressure regulator, and brand new fuel pump, and a whole lot of confidence, I still didn't manage to complete a single lap of Sandown yesterday.

Car went like a rocket up to 4k, where it would just lean out and ping, and refuse to go any faster. Apologies to everyone who was stuck behind me for those 2 outlaps I attempted.

After the first failed attempt, pulled the fuel filter out and it was full of crap. Flushed the fuel tank, put another 10 litres in, flushed again while dad went and got a new filter from up the road and re assembled.

Tried another out lap with the same result, so came back in obviously. Checked the fuel pump and it was stuffed by this stage. Had another brand new fuel pump, but didn't feel the need to destroy it as well, so called it a day.

So tonight I flushed the fuel again, and it seemed obvious why it was struggling. Until I pulled the tank out properly.

The first photo shows what came out from draining it tonight. Had about the same amount of crap in the first lot at Sandown, the second lot "appeared" much cleaner.

I used a rag to filter the fuel as I was pouring it into waste containers so I didn't potentially contaminate them as well. Good move. See second picture of rag. (If you look closely, you will also see a rubber band came out of the tank. WTF?)

Last photo shows the stuff I could easily scrape out of the bottom of the tank- probably around 25% of what is in there. It looks like sand, but crushes when you squish it between your fingers. Given the inside of the tank has some silver coating in it, some brown looking sealant and also some different coloured silver looking sealant, it could be anything. I'm chucking the tank, too big a risk to attempt to clean it.

My guess is that it had all settled to the bottom of the tank after a few years, and I didn't loosen it up enough to start causing problems until Winton.

Very frustrating!

[dehne]

hey matt
i have a spare tank if you need another.

[1969read]

Matt
The tank was chemical stripped , hot galvernized, and a plug put in the bottom then powder coated, for some reason the galvernizing has broken down when the car was sitting for 5 or so years with old fuel in it, sorry l was trying to stop known rust contamiation issues but the opposite result has happened. Jason
I have no idea what the rubber band is but my guess it is the sealant that joins the tank halfs together at the factory and has come un-stuck with the hot dip galernizing process. Sorry that myself and more so you have found out never to galvernize a fuel tank again.But l guess the drain plug is still a good idea.

Very sorry and shows weekend shade tree mechanic like myself needs to learn more. great work with the car jason

[VeeSix]

Well can not blame that one for not wanting to run, may have to clean the injectors again, but too be honest i have bought quite a few old sitting Alfa Romeos over the years especially 90s and never seen that much or that type of stuff in any of them, always pays to flush out a tank that has been sitting for a long time, not that hard a process either, undo the bolts, fuel line and electrical connections and she is out, give a good clean out, empty, let dry and reassemble, almost there Mat, maybe next time  .

[Mat Francis]

Thanks for the offer Dehne, but I've already got another one. Just gotta get new flexible lines as a precaution and i'll re install the lot tonight.

Nevermind Jason, some things get learnt the hard way inevitably. The drain plug is a good idea in theory, but unfortunately I've found it doesn't really do much due to the baffling inside the tank. Even when there is no more fuel coming out of it, I found there was still about 15 Litres in the tank after I pulled it out of the car. If you were to say add 3 drain plugs (one under each baffled section) it would be very effective, but I think this would be a whole lot more trouble than it's worth, not to mention creating 3 more possible causes for failure. Still, a good learning experience none the less.

I'm now out of sprint days to test this thing at, but I'm still confident I can make it work reliably before the 6 hour. Assuming I don't run out of patience!