Friday 22 October 2021

New Battery

 Although I tend to put the battery on a trickle charger a day before a trip, I found that starting was becoming very sluggish.   And the voltmeter was showing that during cranking the voltage was dropping dramatically.   It's over 4 years since I had a new battery do decided it was time to get a new one.

First problem I had is that the connections I use are designed to fit a square terminal rather than the more usual post terminal.   Also the battery tray is a bit smaller than the usual, so a standard 243mm length battery will not fit.  I cannot go above 210mm.

The result was that I could not find a suitable replacement.  On the other hand Europarts had a battery of the required size, but with post terminals.  Also they had a 'winter discount' that reduced the cost from £99 down to £53.   

A quick search on Amazon showed these, perfect adapters.

Once I relaised they were different sizes they fitted perfectly.

Job done.

Thursday 23 September 2021

Lambda Sensor again

 While I was celebrating the MOT pass I was hit with lambda problems again.   As regular readers will know, a failure of the sensor is almost unnoticeable as the car performs normally.   But purely by coincidence I decided to do an instrumented run.   The log immediately showed the problem, in that the lambda sensor voltage was firmly fixed at 435mV and the whole journey was in open loop.

Although I had rewired the system a few months ago I really didn't like my solution so thought it was time to rip it all out and start again.  So the first step was to rewire the heater from where it left the loom.  Before plugging in the sensor I checked that the voltage output was zero until you started the engine then it jumped to 13.5V as the alternator kicked in.

Next I replaced the signal wires with 2 separate screened cables, one for the signal and one for the earth.  Probably overkill, but I happened to have  some single-core screened cable I could use,

So all plugged in I started the engine and plugged in MEMSScan to monitor the lambda voltage.  Unfortunately it stayed at 435mV, although after 3 mins or so it gradually crept up to 450mV, so something was obviously still wrong.

Not sure why I did it but I retested the  heater wires unplugged and found they were still showing 13.5V,  but when I plugged in the sensor the voltage dropped to 0.11V.   So offload it was OK, but under load it was failing.   Next step was to swap the sensor for my spare, but that didn't help and the same happened.

I needed to get her on the road so as a short-term measure (although I am the first to admit my short-term fixes have a tendency to become long-term)  I provided a new feed to the heater using a dedicated earth and an ignition switched 12V.   The downside to that is that the heater is activated immediately you turn on the ignition rather than waiting till the engine is running.   I just have to make sure she doesn't sit with the ignition on for very long.

MEMSScan appeared to show that now everything was working.   So took out for a long run and here was the log file:

 Happy days 😁

So I still don't know why the voltage dropped dramatically when the sensor load was added, I need to investigate that further.

I also now know that the sensor will NOT work unless the heater is on, even when the engine has warmed up to temperature.




Wednesday 8 September 2021

Tracking Check

 Spent this morning playing with my latest toy 😁   She has always suffered a bit from the front unevenly wearing unevenly on the outside.  I replaced the tyres 4 years ago at around the 12,000 mile mark, and it looks like I need to replace them again at 24,000 miles, particularly as one of them was an advisory on the last MOT.   I always assumed it was a tracking alignment error and a few weeks ago I had them checked by my local garage who confirmed it was out and realigned them.

I'm wasn't convinced he did it correctly as she still had a tendency to pull to the left so I treated myself to a check gadget.

Great fun, quite fiddly to set up but eventually managed it.  Practice makes perfect.    Here was the result:

So a slight toe-out but nothing to worry about.   Also it was only a practice run, it shouldn't be on carpet and car needs positioning better so I need to do it properly. 

However, it did make me think a bit about the tyre wear and I am not now convinced I was correct about the tracking, particularly as the wear only really started when I bought her.    So googling it and one of the main reasons is worn out springs causing the camber to change and angling the wheel vertically so the outer edge takes more of the load.   I now realise that compressing the springs to raise the ride height has the same effect of changing the camber by moving out the top of the tyre.   So maybe that is reason?

I still need to buy some tyres and my local tyre depot does free alignment checks (or £35 to adjust it) so I think I will do that.   However, I know that adjusting the camber is not a trivial job, as you have to break the top ball joint and rotate the joint, so I guess they would charge a lot more for that.    Have to ask them.   On the other hand, buying two new tyres every 5 yrs/12,000 miles is not a big deal.

I could also cure it by dropping the ride height, but faced with a trade between replacing the cars or trashing the sump I think the tyres win 😁