Hello everyone
8 months ago, I got a "Emissions Workshop" warning in my dashboard with symptoms being extremely slow acceleration and high fuel consumption though no starting problem. I took it to VW, where they told me that the timing belt had to be changed and the injector pump's timing was not right (code 17656), though they were able to fix it. On my way home, the light came up again, but I couldn't turn around as I was late for job so I kept driving. After I was finished at job, I tried to start the car buy it wouldn't start. It cranked and cranked and cranked and finally started after 10-15 seconds of cranking (I know, it was really moronic as lots of white smoke was coming out the tailpipe). So I parked the car and later in the month had it's timing belt, V-belt and glow plugs changed along with engine oil change. The problem was still there, it would crank but not start, it did start with starter gas, but the car struggled a lot at high speeds. None of the workshops used VCDS as they used a software from Bosch, which only showed the quantity being injected, not the timing.
After months of self-learning about the problem and about the car, I went out and had the starting problem diagnosed, which was found to be misaligned timing belt and again! code 17656. The problem was STILL there. So I went out and asked to rent a VCDS and was hopefully able to find one. So We met today, sat in the car and booted up the VCDS. Upon looking at the timing we saw that the timing on injector pump was way too much advanced (it was meant to be around 60, but it was at 210, look at picture 1 where there is a straight vertical yellow line) that we had to retard it all the way down to 70. Now here was a problem. Everytime we adjusted the timing a tiny bit, trying to get from 70 to 60, it would fall down to zero. And when we tried to get it up to 60, it would suddenly climb to 120 (yes, we did try to move it as little as possible, but wasn't much help).
At last we gave up at timing = 69, though the warning light would still come on, but at least the car was accelerating much better and could easily get up to speed but the fuel consumption was still high. I did eventually found out that the three bolts around the 22 mm nut are meant to be used only once as they're stretchable so those bolts could be the reason why the timing went advancing while running.
So here is my question. Is there a fault with the injector pump? or the 22 mm nut because of the three 13 mm bolts? I do know that there are 13 ,mm bolts that are reusable, but where can I find them? And how can I reduce the fuel consumption (it used to do 5.2 - 5.8 L / 100 km, but now its doing 9 L / 100 km and yes it's and 01M automatic with 210000 km on it which I am swapping it for 02M DRW manual) because it's not getting economical to drive it now. What shall I do? I have already spent quite a lot on that problem without any success. Shall I just go ahead and change the injector pump or shall I try new non-stretchable 13 mm bolts and try to correct the timing?
) I will be trying to replace them on friday as I confirmed that the 3 bolts in my car are indeed one time use only.
