Sunday, May 09, 2010

Big knob bad, small knob good

It's been a while since I did anything frivolous on the PI, mainly because it's been rather annoying in resisting all my attempts to get it running right. You see I made a little mental pact with myself - get it running right, move it towards it's potential. Then, and only then, can you start doing all the other jobs that you have stacked up for it!

So it is with some relief that I think I have cracked it this weekend. I have spent two days on the car and been through it step by step.

First a bit of history - it was running OK, then it developed a persistent misfire that you would not drive through. At this point everyone will be blaming the PI. I have installed an electronic fuel pressure gauge in the car so I can see when fuel pressure drops. Yes sometime it has occasionally dropped (I have had several pumps on it testing and developing) but the low fuel pressure misfire is very different to an ignition misfire.

So I had swapped out plugs, leads, cap, rotor arm and coil for a known good one. I'd gone from points to electronic ignition and back again. All to no avail, so pissed off was I that although I drove down to the Isle of Wight, I refused to use the car on the Saturday drive out.

As can be imagined, it was grim determination that I set about the car on Saturday. I'm pleased I did and I'm also pleased I don't make my living doing this sort of stuff because by Sunday morning I'd made no progress whatsoever! I'd put it back on points and then when trying to time it up found my strobe light had died - annoying or what. I got it running and it was, as my erstwhile friend Dave often says, running like a bag-o-shite!

One of the annoyances about the car is that the dizzy is misaligned and the vac unit points into the head making it impossible to pull all the plugs. I decided, pull it all off, dizzy, metering unit , dizzy drive and rotate the oil pump so that I can reassemble the correct way. This means starting a fresh with all timing (ignition and injection)

This morning I swallowed hard and off I went. It took me ages, assembling and reassembling, making and wrecking then remaking the pedestal gasket because I had none. Realising that now was the ideal time to change the choke cable for a NOS one I had acquired - it's a nightmare to attach it to the metering unit in situ but a breeze if it's in your hand. In doing so I realised that the original choke cable was a little kinked and wasn't allowing the over fuel lever to return to closed - it now does.

So I got the Metering Unit timed in OK, got the dizzy mounted then spent the next few hours trying to get the theory of what goes where into practical application - I don't know what happened in my head but I just kept screwing it up. Over and over until I was just about ready to hit it with a hammer and walk away. Then one last time and with a fading battery from all the turning over to no avail, I was ready for the triumphant return of the PI - yes! It only bloody fired and sounded good.

I had bought a brand new coil (Lucas sports) and it had seemed a good time to throw that on. Whilst I was at it I thought I would check and adjust the valve clearances, the car had sounded a little tappety. It needed some adjustment, not much but most were sloppy.

So the only component that I changed today was the coil - could the old coil and the known good one I was using both be crap? They were both the correct 12v coils (no satanic ballast resistors here). I tried the old coils - all fine!

I even managed to appease the Gods somehow and they fixed my timing light which worked at the first attempt. Timed up and running nicely I then went for a blast down the road, it felt good. I drove home and popped the bonnet to admire my work, the engine sounded a bit chattery, something wasn't right. I got my American "Mechanics Stethoscope" out (Thanks Bill) and narrowed it down to the dizzy, it sounded like a bad bearing. Not much I could do about it now I thought. Let's check the vac readings, make sure the engine is as healthy as I think - pulled off the vac tube on the dizzy and stuck it in my gauge.

Hang on!

The noise has stopped! Re-attach the vac advance and the noise is back. It's definitely something to do with the vac advance unit, what I don't know. I pulled the cap off and checked for any fouling of wires or anything obviously loose. The only I can think of now is that whilst I was assembling the points I thought the cheese head machine screw that hold the points on was a bit long (but it's the one that came with the car). I think I'll try the electronic ignition back on again next time I fiddle.

Anyway, vac off let's got for a blast - ooh now that is nice. Pulls well and feels strong. I'm a happy bunny.

As for the title of this post, I bet you're wondering what all this has to do with knob size. Well let me tell you, as a Mk1 owner I have been trying to get all my dash knobs to match but the choke cable knob has never been right, always twice the size of the other knobs - Mk1 PI choke cables are not common on the open market. Now, with the new choke cable I got a choice of two small knobs in the Stanpart bag. So I used the correct one and all is well with the world, I am small knobbed again and proud of it.

So other jobs to do are now looking possible, that is now that the car is running well. On the list are:-
  • Replace the leaky seal in the fuel pump - I must have put an old pump on in my haste
  • Fit these longer Ford RS studs I've just bought so there's some thread showing through
  • Repair the passenger seat, the seam stitching has let go completely now
  • Fit the air horns I've had on the shelf for 3 years+
  • Fit the HID headlight upgrade I've had on the shelf for 2 years+
  • Fit the underbonnet sound pad with these nice stainless retainers I've had for a year
  • Stop making lists

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