Tuesday, April 14, 2009

Thanks Bert

I've been struggling with the PI, I think I've turned the corner thanks to Albert Einstein. You see I have a "Home Page" on my PC that includes a daily random Einstein Quote, I'm trying to increase my bullshitting repertoire. Anyway, today's quote was

'Insanity: doing the same thing over and over again and expecting different results.'

and as I sat there looking for inspiration this morning I figured that was good advice. Let's go do something different!

You see I couldn't understand the results I was getting with the fuel injection - bubbles in the now clear line (sometime you can have too much information) and poorly injecting on No1. All unions tight, no sign of leaks, everything all as it should be visually. I had changed out several components and generally messed about with the usual suspects. All my test readings on my pressure gauge were OK but it would still not run well, popping and farting like me after a curry and bucket of lager.

I decided to see what would happen if I exceeded 106 PSI at the metering unit and went up to an indicated 120, the racers do it, so why not?

Bingo! Bubbles cleared in the line. The injector was still not right but better, I swapped it for No2 which was fine, that told me the injector was faulty. I rummaged in my spares and found a better one, not great but better. She runs without the popping and stuttering, seem far happier at idle and is worthy of a road test, or two :-)

I will take stock of what I have and see if I can sort out a recon injector, I don't want to run with this one for long. I have some seals somewhere to put in an injector but I haven't yet figured out how to test the trigger pressure. There's not much too them but I am guessing that they all need to trigger within a reasonable pressure range of each other. The book says 60 PSI I think.

That leads me to another idea to make up a test rig and pressure test some of this kit I have lying around. I've got loads and some of the pumps look great but there's no point in keeping useless spares and there's no way of knowing if they are crap until you pressure test them!

This episode today has encouraged me to sort out the plumbing in the boot of the PI, I fancy putting the pump over on the driver's side, away from the heat of the exhaust. I'll also put a fuel tap in there so changing the fuel filter isn't such a messy job! I'm also told that Mk2 plumbing style is better with the pump on it's side, I have the necessary cradle and cooling coil combo on there at the moment as a temp set-up. The pump is NOS. I now have a glass bowl filter so I think I'll put that in the OS wing and modify the trim around it all.

Anyway, that's the midday update, MOT this afternoon so now my dear daughter has shown her worth and provided me with a bacon sandwich, I can get back to the car :-)

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