So, following on from Wammers suggestion here (
http://www.landyzone.co.uk/lz/f10/diesel-pump-timing-tool-set-dial-gauge-280977.html) to use the Nanocom to set timing ...
... I'm really mystified. The results of yesterday's tinkering are inconclusive as far as I'm concerned.
Is it possible to do without removing the manifold? Well, I checked my toolbox and none of my hammers could fit in. Plus, I couldn't "see" in my head what I was trying to achieve and I couldn't see an easy way of slackening off all the high pressure fuel pipes. It didn't take more than a minute to decide that for the sake of ease of access, 15 minutes to get the inlet manifold off was well worth it. Having done it I stand by this technique, especially if this is your first time at this.
I took the car for a good run and then parked up, got the Nanocom out and plugged it in for a baseline reading (air-conditioning off). The live readings on the screen showed timing modulation of about 83%. The live trace recorded agrees with this and can be found here (1):
https://drive.google.com/file/d/0By7n3F7TXDU8MGJhWDhhOE9jRms/view?usp=sharing
I then whipped the manifold off, started the car, gave it a minute or two to get the coolant distributed and let the revs drop down to 750rpm to get a baseline without manifold (air-conditioning off). On-screen modulation of 80% agrees well with the live trace here (2):
https://drive.google.com/file/d/0By7n3F7TXDU8VWZoWTlmaUdTdkE/view?usp=sharing
I then made a series of marks on the fuel injection pump (FIP) casing and timing cover, alternating between scribed using a bradawl and also a permanent marker so I had a crude gauge.
View attachment 70620
I completely loosened the nut on the bottom of the bracket on the rear of the FIP and slacked the front 2 nuts. What followed was an incredibly frustrating few hours of tapping the pump towards the engine to reduce modulation, tightening the front 2 buts, starting and warming, taking a trace and then tapping it back the other way to increase the modulation again. It seemed to either sit in the eighties or sit in the teens and refuse to stay anywhere in-between. A couple of example traces and photos of position are below. All done with air-conditioning off.
(3)
https://drive.google.com/file/d/0By7n3F7TXDU8MjZNbDFxdVJrc2M/view?usp=sharing
View attachment 70621
(4)
https://drive.google.com/file/d/0By7n3F7TXDU8bjdqRTZEem9fc00/view?usp=sharing
I then decided to be a little risky and leave the engine running while tapping the pump. Fortunately a neighbour had come out to show solidarity at this stage so I got him to sit in the car calling out readings with instructions to kill the ignition if anything looked at all out of control. What we observed had both of us foxed. If I left the pump at 11% modulation it seems to stay there. If I leave it around 83% it seems to stay there. If I leave it anywhere in-between, say 30% and lock it off, it stays at 30% for a short time and then creeps up to the eighties. If I put the air-conditioning on then the modulation rises, if I switch it off the modulation falls again.
(5)
https://drive.google.com/file/d/0By7n3F7TXDU8ZEZlS0w0UzRFLVU/view?usp=sharing
View attachment 70622
After much mucking about I decided to call it a day. I got the modulatation on 40%, tightened everything up, put the manifold back on and then went for a drive. No difference as far as I could see. Once back I parked up and took a final trace (6):
https://drive.google.com/file/d/0By7n3F7TXDU8WUk1TnZ6a1k1dXM/view?usp=sharing
View attachment 70623
Here it gets really weird. Everytime I put the air-con off the modulation drops into the 30s. Switch it on and it rises back up to 84% - pretty back where we started the day, even though the final position of the pump has clearly moved towards the engine. Similarly, if I rev the engine or drive for a bit and then stop and let it idle, the modulation one more drops back to the 30s / 40s but then slowly creeps back up until once more it sits in the early 80s.
I cannot get my head around this. Surely if it was mechanical then it'd just stay where it is? Which makes me suspect some sort of electrickery is somehow pushing it towards the stable values of either 80% (or 10% when the pump is turned more towards the engine). My feeling is that there's more than one thing affecting this and I don't have all the pieces of the puzzle yet.
Unfortunately I'm the sort of person who never reads manuals. I tend to work things out from first principle or ask someone and work it out from there. However, I'm getting the horrible feeling that I'm going to have to dig out as much as I can on the EDC module, the workings of the FIP and that mysterious hot-start fix that is fitted and try and map all the interdependencies because I just cannot get a model in my head that feels right at the moment. Unfortunately time is my enemy there, although admittedly there might be more of that if I hadn't been so busy marinating my brain in Chiltern Black ale last night!
Hope that's of interest to Brian / whoever.
J