Going East - getting a UAZ 469 back on the road

[RangerNeil]

I took advantage of the decent weather today, broke out the multi-meter and ran some checks this morning whilst the battery was charging.
First I checked the feed line to the sender - there is definitely +12v to the terminal at the sender end.
So I ran a continuity check between the sender terminal post and earth. Nothing.
Next step - I removed the sender and checked the resistance. At one extreme of movement - low tank - it was 9.3 ohms. At the other extreme of movement - full tank - it was 94.9 ohms.
Then I switched back to continuity and this is where it gets weird. I had continuity from 9.3 Ohms up to 46.8 Ohms. Above 46.8 Ohms there was no continuity. So when the tanks just over half full the sender loses continuity - as the tank is nearly 3/4 by visual inspection check it explains why the gauge behaves as it does. What it does not explain is WHY there is no continuity above 46.8 Ohms.
Unfortunately the wife has thrown the two old ones away so I cannot check them. Next step will have to be to open up the drivers side again, pull that sender and run the same test. If I get continuity across the range of resistance the then I have a faulty sensor If it is the same I have no idea why and what to to do next as, even with Russian stuff, the odds on getting two parts that "fail" the same way are remote to say the least..

I also managed to correct the brain fade of yesterday and remove/refit the fine fuel filter such that is now on the right way up!!


As the battery was charging I did not try starting the engine today. However the fact that the new starter was virtually as slow as the old one and I had been told it should spin over like a normal vehicle says to me there may be other issues at play. I had a look at the wiring and was a bit concerned by what I found. Both the main feed from the battery to the starter solenoid and the heavy duty feed from the starter solenoid up to the silver box (relay?) seem to have broken strands and the low duty cables to the two small terminals on the starter solenoid show signs of over heating.
I am wondering if the cable damages are responsible - at least in part - for the slow starter speed???

[RangerNeil]

Well..... Tried to start again today - and it spun over a LOT better and fired. Left it running a while to warm up and also tried switching over the tank valve to the passenger side tank - it kept on running so all seems well.

Once warmed up I switched off and then opened up the access to the drivers side tank sender. Again - 12v to the end of the sender wire as may be expected and there was continuity from the terminal post to the earth screws. But this tank is nearly empty so to test I took the sender out again and ran the same check as on the other side. To my amazement this sender did exactly the same thing Readings for resistance were the same , low and high and the continuity cut off at roughly the same point. So in theory when this tank is filled past the half full level the gauge will go open circuit again on max deflection.

Folks - this does not seem right!! But these are two brand new senders from Tarmot and I cannot believe that, even with Soviet Russian QC standards two senders would both have exactly the same fault on them.
And I do not understand how I can trace a steady rise in the resistance reading from one extent to the other which implies a circuit and yet once the resistance reaches a certain point I no longer get a continuity signal. Either there is an electrical path or there isn't.
If there isn't a path - why do I get a resistance reading across the full range of sender travel?
And if there is a path - why do I lose the continuity signal over 46.8 Ohms?

Anyone got any thoughts or ideas because I am totally baffled!!

[JPB]

Is your meter an auto ranging type, or do you have to switch between ranges to measure higher or lower values? In the case of a meter that doesn't change automatically, it would be quite usual for the reading to show a zero with a point or an arrow to tell you whether to change the range up or down to suit the reading you're trying to take.

[tractorman]

Loss of continuity may be something to do with the meter. Continuity usually implies "short circuit between two points" and 40-odd ohms isn't a short! Measuring resistance will give a more "honest" reading throughout the range and, if it varies "proportionally" across the range, I would suggest that the sender is working. I used inverted commas as, in real life, they are not truly proportional!

Also, in real life, few fuel gauges are accurate throughout the range. Apart from hysteresis giving different values at a level while you fill and while it is used, the makers usually try to make the lower end of the scale more accurate (and often pessimistic towards "Empty" as is is more useful to know when the tank is running out than how near the maximum it is.

[RangerNeil]

Meter is a manual range selector type. I was using the 0 - 200 Ohm setting which is also the one for continuity testing.

If you look at this video clip you can see what I mean about the meter going full scale deflection due to open circuit/ The UAZ has a manual change-over switch, unlike a Landrover, and the middle position is akin to neutral - gauge is live but no tank is selected. Top position is the drivers side tank, bottom the passenger side.

https://www.youtube.com/watch?v=eV9uipmpTtg

You can see that as the switch goes from the top to the middle position the gauge needle shots over the right - this is normal. However when it goes from the middle to the bottom the needle remains hard over.

When I tested the senders I held the probes with the +ve one hard against the terminal post on the sender and the -ve one wedged tight through a screw hole in the sender base; the sender float was then gently moved up by pressing the sender down onto the floor of the vehicle making the sender arm move through it's entire arc of travel. Starting at the 9.3 ohm reading the continuous tone of the continuity test could be heard but as the resistance value passed the 46.8 Ohm mark the tone stopped. The resistance value kept increasing though - and this was the same on both the new senders.

The sender that is currently working - the driver side one - is reading reasonably accurately given a visual inspection of the tank level. I am tempted to go fill a jerry can, leave the ignition on and pour the jerry can in to the drivers side tank to see what happens as the gauge passes the halfway mark - if I am right this tank will go open circuit too.

[RangerNeil]

Tried swapping the senders over - still doing the hard deflection on the passenger side. So either both senders are faulty - which, knowing Russian QC, is possible or there is a new fault in the wiring from the switch to the sender. Next step is a fly lead between the two to see it it still acts up.

Meanwhile - the official number plates have arrived and been fitted today so the UAZ is is now technically legal to go for a rumble in, Just got to sort out the brake lights being on constantly - the starter got dropped on the switch whist removing it so possibly that has screwed it up. I am told the classic Mini one is a straight swap but I'm awaiting confirmation before I try it.

[RangerNeil]

Well = brake lights are, in theory, sorted. A news switch id fitted - but - this is where I found out that the union it mounts into was supposed to be bolted to a bracket on the body - and wasn't. So every time I heaved on the spanner they rigid lines flexed. To the point where, as it wound the last few threads out the pipe feeding the front axle split. So - in view of the fact time is now running out to get it ready for W&P - it will be going into a local garage to be sorted. I just do not have the time what with the Landrover and the OT-90 to get fixed as well.

[RangerNeil]

New brake lines fitted - I took the old ones to a local garage and asked them to use new 12mm x 1 unions and to give me the old pipes back to use as templates for bending.
When collected they had re-used the old rounded unions because " they had no imperial sized ones in stock" and had crushed the old pipes into a bundle. To say I went totally Librarian poo was an under-statement!!
However after much cursing and bending around bean tins the new lines are now fitted and the system just needs re-bleeding again.

[RangerNeil]

Good and bad today.

The good first - I got a chance to look at a couple of other UAZ's over the weekend at Capel and found out why the fuse for my spotlight kept blowing - I put a bolt through the hole that is only meant for the cable! Removed the bolt today and replaced the bared wire - result spotlight now works without blowing the fused supply.
Also took the cables off the back of the cut out switch and cleaned everything up so now it spins over a bit faster when starting.

Bad news next - I got the brakes bled - and the brake lights are still staying on. So, it seems are the brakes. So tomorrow it will be a case of jacking up the axles and trying the wheels, backing off the brake shoes and seeing if that helps matters. I hope it does as the other option could be the flexi-hoses. This is what I do not want it to be as I only have 3 new ones......

[RangerNeil]

Looks - he says with everything crossed - like success
The actuator rod from the brake master cylinder was the culprit responsible for the brake lights staying on. I removed the boot from the adjuster nut, released the lock nut and wound the actuator in until I got free play in the linkages. I must have taken it a good 12mm at least, possibly as much as 15mm. Once I had the free play I tightened the locknut and replaced the boot onto the adjuster then checked the brake lights - they are now off all the time until the pedal is pressed.. So next is to go for a short test drive to see how well it goes and whether I need to adjust the brakes further. I hope not as there isn't much left on the adjuster now!!
Once the brakes were sorted and the under-guard plate bolted back on I drained the fuel out of the passenger side tank into a bucket - took 3 sessions as I only had a 20 litre bucket - and poured it into the drivers side tank, this being the only one currently the pump will draw from. Those filler necks - even when extended are not the easiest to pour into are they?? I must have lost a litre in spillage between the three pouring in sessions.
When the fuel transfer was complete I turned attention to getting the door mirrors fitted. Putting them where they look to be on the photos I've seen got the bolts hit by the door checks as the doors shut so I had to move them back and up a little. Could not go any higher as I could not reach up further to get the washers and nuts on!! Still - they are on now and when I get the new doors from Tarmot I will reconsider the locations. May need tweaking position wise once some miles are covered. As of now this is how the old bus looks:

http://i34.photobucket.com/albums/d146/ ... ei2nz8.jpg

Today was the first official test drive for the UAZ!! It went well with a few lessons learnt in the ways of things UAZ. The old bus started well after being left for 24 hours - first lesson learnt was to leave her to warm up a bit more before trying to drive off as the intial few hundred yards were a bit spluttery engine-wise. However as soon as it did warm up it ran and pulled strongly. Gears went in without crunching apart from 1st. Gear change was pleasant and not as vague as a Series Landie (the comparator for the day). Speedo was "interesting" to put it mildly - although calibrated from 0 kph the vehicle was actually rolling a few yeards before the speedo started to register and then it flickered reading approx +/- 10 kph for any speed. Either the cable is sticky through lack of use or it needs replacing. Or it is routed incorrectly and is being tapped by the cover plates. What ever - something to be investigated. Turning circle was a bit bigger than the Landies but once I knew what to expect it was not a problem. The ride was surprisingly smooth given the cart spring technology suspension - most notably over speed humps. The landie tends to try and compress the spine when going over them faster than 10 mph whereas the UAZ rolled over with minimal discomfort at 50 kph (30 mph). There seems to be a lot more vibration whilst rolling as compared to a Landie - the door mirrors in particular moved a lot whereas the Landie's are still. That could be down to the UAZ doors being basically f*cke*d and falling apart though.
Overall I was very pleased with the run and am now looking forwards to a longer one tomorrow to get to the Ford R&D centre at Dunton, just off the A127.