Monday, June 14, 2010
Thanks to Andy Martin's camera in the hands of I think Dave Pearson here are a few action shots of me making a mess of the test circuit. All I can say in my defence is that I was laughing too much to notice where the cones were and was completely unable to control the old girl around them anyway. Turns out I missed only one which I count as a superb victory!
First is the calm before the storm, you get a 5,4,3,2,1 count down and then you're off!
This was me trying to give it some welly to drift round a cone
The result of the welly giving was to produce an impressive cloud of dust and missing the cone by a mile.
OK so I was on the wrong side of the cone!
So I finished with an impressive fishtail - OK perhaps I was the only one impressed
Sunday, June 13, 2010
...because you alternate between thinking you've fixed and not!
This is getting very silly indeed, I though maybe I had a dodgy alternator so I started checking that out today, Oh hang on, let's get back to the beginning
The symptoms are that there is a persistent misfire, it's not on a specific cylinder but it's more like she's not fully firing all the time. It's through out the rev range and doesn't seem to respond to any fuel or ignition settings (choke in/out, advanced/retarded) you can't "drive through" it.
Engine is fresh and has excellent (190psi) and equal compression. Cam timing and valve gaps are all spot on. Metering unit is timed correctly, all injectors are spraying a good cone pattern with no dribbles or bleed back.
I have replace or rebuilt all of the ignition system at least twice. New coil, leads, cap, rotor arm, plugs, points, (tried electronic ignition too).
The fuel system is OK, pressure seems pretty constant over 100 psi on the electronic gauge. The gauge seems to only want to read up to a max of 102 psi despite it being a 160psi one. The injection seems to work OK as she will run right down to 80psi or less before she stops or chugs.
So, back to the alternator - why do I suspect it? Well it's a recent recon ACR type of unknown origin or output (although I think it's an 18ACR). It replaced the one that came with the car (also and ACR) that I suspected was faulty, it wasn't charging properly - but now I'm not so sure!
Anyway, the misfire is still there but if the car is running and I switch the lights on, I get a pronounced misfire. I get the same type of misfire if I wound the horn (air horns) for a 2 or 3 second burst.
So, I test the alternator to see if it's failed or not. Now it gets interesting - vehicle electrics are not one of my best areas of skill - I admit to being a bit of a thicko here. Electrickery is one of the great unknowns for me and operating a multimeter is a challenge. Getting the test results is OK but what do they mean and are they normal?
Well here's what I got.
- Ignition off - voltage at the battery 13.06v - seems healthy
- @ idle - voltage at the battery is only 12.9 volts but....
- @ fast idle - voltage at the battery is 14.17 and it doesn't get any more at higher engine speeds
So that would seem to indicate that the alternator is charging OK.
So then my mind turned to what was the voltage at the coil whilst all this was going on - now I'm not too sure what these readings mean but I took them so I'll thrown them out to the Triumph intelligenci and see what comes back.
- Coil resistance is 3.7 Ohms, correct for a non-ballast resistor set-up
- Voltage at coil with engine at idle is 5.7 volts and it drops to 3.2 volts at fast idle
- Voltage between battery negative and coil positive at idle is 6.29 volts and it drops to 4 volts at fast idle
- Voltage between coil positive and battery negative is 12.55 volts at idle and rises to 13.6 volts at fast idle
It's fair to say I haven't a clue as to what all that means but it doesn't look right to me.
The next fun is the wiring - here's where a factory diagram isn't much help. As a Mk1 PI it should have a Lucas alternator with a separate control box. It doesn't have anything of the sort, it's got wires bundled together and a few brown ones not plugged into anything at all, just taped up out of the way.
There are three wires connected to the alternator, the chunkiest brown one goes straight to the battery positive, a thinner yellow and brown wire goes from the centre terminal on the alternator into the loom. There's a thinner still wire which is brown and green and also goes into the loom.
So a few questions for anyone interested in helping me make sense of this.
- As I see it, the Brown/Green wire is the warning light wire and should not have any effect on the efficiency of the alternator. If it's only used for energising the alternator then when defective the alternator will not charge. As mine does charge then my logic says leave it alone! Am I right - the wiring diagram shows this should be a Brown/Yellow wire!
- The Brown/Yellow wire, being chunky, must carry some of the charging current (rather than being the energising wire) but where does it go? I can trace it into a cheap and nasty after market crimped joiner near the fuse box on the other side of the engine bay but where it goes after that I'm not sure. Does it supply fuse number 2 - headlamp flasher relay, horn and interior light/Cigarette lighter?? Am I right - the wiring diagram shows this should be a Brown/Green wire!
- The heavy duty Brown wire goes straight to the battery, that's easy.
Anyway, enough of such things, I'm off to fiddle again but this is baffling me! All suggestions gratefully received!
Saturday, June 12, 2010
What a weekend! I was well prepared (as I always feel I am, I'm usually wrong) and drove up to Canley Classics on Thursday afternoon to meet up with Dave. The intention being to have a final fettle and see if we could cure an annoying brake judder on Thursday then have a leisurely start to the journey midday Friday. Joe and Frank Welling were also starting from Canleys and Tims Bancroft and Hunt were going to meet us there to travel up to the Old Stone Trough on Friday. We were due to set off at about 1pm. That all left plenty of time for the inevitable "issues" that crop up.
This event would the car's longest journey in my ownership, in fact it was 1500 miles door to door. I'd had an annoying misfire for weeks before and felt I;d cured it, the car went well on the 100 mile trip up to Dave's place, I didn't push it.
Of course things started to go a little pear shaped when the misfire returned and the brake judder got annoyingly worse! We resolved to sort the misfire first and then move on to the brakes later.
By the time Friday came we'd basically done a full service on the car again and were hooking it up to Dave's Crypton machine, a formidable piece of kit with valves and all sorted of radar like traces on a screen.
It was frustrating, we found stuff that was wrong and with satisfying "Aha" moments we fixed one after another only to be left with the same misfire.
Metering unit timing was changed, ignition timing was fiddled with, plugs were changed, compression test done (bang on - all cylinders the same at 190psi) vacuum tested - everything was spot bollock on. It should be, the engine's pretty much new having been build around a Witor cam and barely run in. I even found a dribbling injector which I replaced with a new one.
On the last test run I took the car out and gave it a spanking down the lane, where it promptly birdsnested it's fan belt! It had looked a bit weird and I'd checked the tension earlier but better it went then than on the run up or worse, in the Highlands!
Because the PI has power steering it was a little bit of fiddle to replace as I needed to take the PAS belt off first and it's quite tight, not to mention red hot down there - I did utter a few expletives as I singed my arms repeatedly.
Joe Welling was having fun too, he's rocked up with his Vitesse dragging it's arse severely - the lowering block was just too much. There was no way he was doing the event with the car sitting like that so he removed it. The new alternator wasn't charging which turned out to be a wiring error, all fixed without drama.
Tim Bancroft pitched up early and Tim Hunt was on time so off we went into the scorching midday sunshine. As ever, the M6 was a bloody nightmare and we started to get some fuelling issues with cavitation. The pump screams as it starts to pump vaporised fuel. This leads to a drop in pressure as shown on my gauge. The PI will run right down at 80 PSI but it's not very pleasant. As soon as you get any lower the injectors start to suffer, they crack open at about 60 PSI and if they don't get enough pressure, they just don't open!
Once or twice we thought we'd be on the hard shoulder but we never actually died. We made it to Barnoldswick in good time and apart from a little underbonnet issue we were OK - I had spare pumps I could change it when we got to Gretna. The underbonnet issue was that the plenum had pulled one of the steel rings out of the alli throttle bodies - I hadn't fitted the support for the plenum and the weight had just been a bit much. So I cleaned it up and applied some Araldite, Tim B gave me some lock wire and I wired it all up so it couldn't go anywhere, job's a good 'un.
At Gretna we took a look at the pump. It was then that another one of those "Aha" moments happened.
Now those of you who know Lucas PI will know that there are a lot of pipes and flows of fuel around the car - high pressure supply to the pressure relief valve which provides two outputs, one is the regulated 106PSI supply to the metering unit the other is a low pressure "spill" which goes back to the tank, sometimes via a cooling coil wrapped around the pump. This cools the pump body. There's also a spill from the metering unit of low pressure fuel that goes back to the tank.
So you can imagine that it's easy to get confused or to see "solutions" that ignore some simple rules of physics. Yup, you've guessed it, I got it wrong again :-) What I'd done was to route the spill from the PRV round a cooling coil and back into the filter head. Neat but with one tiny little flaw - you see what I was doing wasn't cooling the pump it was making sure it got the warmest fuel in the system! Warmed fuel would go back into the filter under mild pressure, that would overcome the gravity pressure of the cold fuel in the tank and yes, recirculate through the pump! What a plonker. So a quick re-plumbing was in order. I needed a T piece to splice the return into the low pressure spill return into the tank -
I'm not sure how it's supposed to go as I think I have a Mk2 saloon tank rather than a PI tank but I'll have a better look and figure it out.
I pulled a T piece off my vac gauge and spliced it all in (I always carry a PI parts kit in a boax that includes Araldite, pies, clips, vac gauge, spare injectors, metering unit, pump, seals, o rings etc).
Although the pump had behaved from Barnoldswick to Gretna I swapped it out for a spare I'd built up. I didn't bother with the cooling coil at this point and we never had another pump issue all weekend. That said, the M6 episode was doubtless because the air temp was so very hot!
Anyway, Gretna is a weird place, unlikely looking wedding parties and coach parties of pyjama clad teenagers. We got our heads down for some sleep and an leisurely start.
Here we are at the start next to Frank and Joe Welling in the Vitesse.
The event was a cracking good laugh, weather was excellent, loads of sunshine not much rain. Memorable parts include my first ever attempt at an autotest (I was crap) plus the Corkscrew which is an insane road click on the link, go to Google Street View mode and you can virtually walk up it. As you can see, it's a bloody tight set of hairpins that are impossibly narrow and steep. It's at times like this you realise just how crazy we are to do these things!
The Autotest at Inverary Castle was interesting, a dusty gravel section proved more visually entertaining than competitive, not that I was trying to put in a good time. I was just trying to do the course properly, failed on that one - "You missed a cone!" said the timekeeper. The truth is, I saw it, I just couldn't get the car round it!
We lost a few people during the weekend, Tim B to a wheel bearing failure, seems they were fitted too tightly and we didn't catch the issue in time before the nearside was wrecked. We tried a rebuild at the roadside just overlooking the submarine base. As if that wasn't enough we also lost Joe and Frank Welling on the route home, just south of Shap when a wheel bearing on his Vitesse exploded in the fast lane, Franks's laundry bill went up but the car made it to safety on the hard shoulder.
Epic performance of the weekend ,ust go to Dave Langrick who finished a chassis change on his 6 pot Spitfire then drove solo from Nottingham to Stirling to meet us. Dave stuck with it for the rest of the event and drove home with Dave and I - top down in the torrential rain and sunshine. What a mentalist!
Issues on my car - fast indicators, crap brake lights, persistent misfire and the ever present brake judder - I loved the weekend.
We did about 22.5 MPG which for the type of driving and the state of the car wasn't so bad - the Vitesse did 19 on the same event 2 years ago and the same on the Ten Countries so 22.5 is an improvement!
I haven't yet had a proper look at the issues, I arrived home at 21:30 on Monday, went to bed and was on a plane to Dublin the next morning for work. Yesterday was my Birthday and today I've been catching up on RBRR stuff. I might get a looksee later.
Check out the last 15 minutes of BBC Scotland's TV programme "Landward" episode 10BBC - BBC Two Programmes - Landward, 2010/2011, Episode 10
There's also a write up from the organising club, the here
Tuesday, June 01, 2010
Went out to the local group meeting - it's a TSSC meet (I was the area Organiser when I was a TSSC member) but we welcome everyone from any club, no questions asked. It's a half an hour drive for me as it's in Hook, the other side of Reading and down towards Basingstoke. Nice blat along some country roads and the PI ran very well indeed, no sign of the misfire and actually feels pleasant again.
Two issues cropped up, the brake judder is not improved, if anything it's worse, despite correct hold down hardware now (thanks Ted) and despite everything working seemingly as it should. I can't figure it out, the brakes judder and it doesn't come through on the steering wheel so I'm guessing rear wheels. Yet when I apply the handbrake (whilst moving) there isn't a trace of judder. More head scratching I think.
The second thing? I flashed my headlights and the fuse blew - it didn't mean the loss of headlights, just the loss of horn, interior light, cigarette lighter and headlight flash. It was a 15 amp fuse. I don't know if that's right or not (Mk1 owners please tell me) I had some spare 35amp ones so I've thrown one of those in but I do need to investigate.
All in all a pleasant trip, I feel a little more confident now - of course two 30 minute drives means she'll make it 1500 miles to and around Scotland and back :-)