Saturday, March 28, 2009

Forgive me for I have sinned

Forgive me for I have sinned

It's been 5 months since I last drove my PI

I know, I know - I've been busy in the country and others!

Grab a coffee, this is a going to be a long one.

When I last drove the PI, it was missing and would not pick up very well when you floored it - to be honest it's a new engine, the car had been off the road for 30 years and in the workshop for 5 (ish) so I was taking it steady but now it was time to fix it.

I found the throttle spindles were worn and decided to change them for a mint Mk2 set I had.

I then checked for injector dribble (it's an age thing) and sure enough I had a dribbley injector (No1) I took it off and found a couple of little black rubber bits in it - ah-ha says I in my best mechanic voice, Thar's yer problem.

Fortunately no one was looking and I carried on as if I were sane - the black bits looked like the rubber seals in the metering unit breaking down - I remember Dave telling me that the PI kit was "picked over" and fitted to get the car running, it could need attention he said (this car was finished on a budget for the previous owner and whilst some stuff was top of the line, I think he'd run out of money/interest/parts by this time).

Anyway I digress. I cleaned out the lines and decided to fit a good and known metering unit from my stash. With all that done I then ran out of time and went to India.

The winter came and I am a light weight, the car sat until a few weeks ago when it started to get warmer and I went back to finish the job, I never managed it but at least I got to a point where it was just a case of bleeding through the system and firing it up! Yeah right.

So the first thing I do today, within 10 mins of getting in the garage, is to slip with a spanner and break No 1 injector pipe. I admit, I swore.

A lot.

Birds left the trees and small animals retreated to their burrows.

My neighbour, a nice doctor came round to see if I needed an ambulance.

OK time to make a new pipe, I have some clear pipe that's suitable (it's commercial vehicle airline hose). To fit the ends you need to make a tool, the manual tells you to use unobtainium, a sort of nylon like material, to make a clamp. Well what fun I have had! Three attempts and the Mk 3 clamp worked OK
Mk1 was a bit of an HT lead clamp, never made it past the prototype phase
Mk2 was the nylon arm that connects your toilet flush handle to the plunger inside - tried a few times with this but it didn't clamp enough.
Mk3 was a bit of wood, made in 3 mins and worked perfect first time out!

I now have one clear line and 5 black ones but I'm not going to mess with the rest until I figure out why I only have 85/90 psi at the metering unit and insufficient pressure at the injectors to trigger them! The should blow at 60 psi so this is looking bad.

I changed the pump (because it was easy and I have a couple of NOS ones) and I am now attacking the PRV but I don't think I have a known good one to play with - the one on the car should be good but who really knows.

I honestly don't know how the PRV works, I mean I know what it does and I have a reasonable idea of how it does it but I like to understand. Why would a PRV fail and why would it go from 106 psi to 90psi. Adjusting these things is a pain in the posterior because you have to partially dismantle it to do it then of course you have to put it back together to test!

Anyone got any experience with Prestige's modern PRV?

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