Hi, a few things to start with:
1, Play in the steering. The steering box is adjustable, but needs to be done with care, get it wrong and you find the roundabout your on you will not be able to get out of as the steering can jam in one position., you say it is lifted, can you do a check to let us know by how much? Any vibrations from underneath that vary with speeds?
2, A jerk in the steering, if the lift has not been done in the correct manner and the springs are not rated correctly the front axle could be hitting the bump stops? Also whilst under there check the steering box mounting around the chassis and the same for all other connections including the panhard rod, at that age the chassis could be rusting allowing the components to move and in a worse case scenario tear out completely, a steam cleaner or jet wash and a wire brush are your friends here, with the 80 on the floor, have someone rock the steering hard from side to with the engine idling at the same time you use a torch and look for any flexing of the suspension/steering/panhard connections including to the body and between each other.
3, The noise could simply be the starter, if that is the case and depending on the stater age, the starter gear might not be clearing the starter ring on the flywheel as the engine starts, easy to correct? Other noises could be if the under floor heater pipes have been modified cutting out the heater as the pipes often rust through, if not done properly the cut pipes bang on the bulkhead where they have been bypassed as you start up, other issues could be the engine mounts failing allowing components to touch as the engine fires, loose exhaust or missing bracket/mount.
4, A compression check would be advisable before a tear down, a service and timing check along with a set of injectors would be good as well if the compression check comes back good. Being a a twin cam petrol engine it has a timing chain so no worry about the belt. That is not a really high mileage engine but it depends where the mileage was done as it does make a difference.
5, The lighting on the 80 is generally OK assuming the wiring is good and the relays are working correctly, here in Spain there are many country roads and I find the dipped beam a little 'wanting', main beam is fine, I recently changed out the dip/main bulbs for a pair of 'Philips' version, these bulbs have a blue tint apparently giving me a 'whiter white', yeh I know, that sounds like a washing powder advert, I cannot presently drive due to recent brain surgery, so cannot comment if this has improved anything, you can upgrade the bulbs to higher wattage's, but this mean more load (amps) on the wiring and relays (not the most reliable on these older cars), again easy enough to get around.
6, Flushing all coolant and oils always a good idea, I do a 'sacrificial' flush on the engine using two filters at the same time, the oil in my engine on the dipstick as clean as it went in despite it being diesel!
7, Oil pressure, the senders do go bad and over time so does the calibration of the gauges, you can re-calibrate the sensors/gauges on oil, coolant and fuel gauges, it's an interesting fact the temperature gauge is 'dumbed down' on the 80, so it often reads in the middle within a few minutes of starting and never goes above unless the engine is close to serious overheating, again a simple modification with a couple of resistors can sort this, The volt meter can be adjusted but as long as the needle is in the middle with everything turned off including the ignition, and doors are shut it rarely goes wrong, and without decent graduations it is a guide only, use a decent volt meter on your battery to see if all is well.
8. A change of gearbox oil has to be done a couple of times to get it clean, draining the sump does not drain the torque converter, you can faff about disconnecting the oil cooler and pouring fluid in as old fluid comes out, personally I would get it warm (not hot), drain the sump and change the filter, measure what came out (assuming it was correct before you started), and then refill with the same go for a drive just for a couple of miles going through the gears ensuring the valve body gets some of the new fluid into it, then drain and refill again, not changing the filter this time. Depending on mileage covered during your ownership I would consider a drain and refill once a a year for a couple of years to keep everything tip top.
9, Re the fuel pump, the main tank feeds the engine and the second tank feeds the main via a switch on the dashboard, if there are some models that have the twin pumps that is handy if you have a pump go down from a get you home point of view but the two pumps would have to be similar pressures, I am not familiar with the two main pump system,
@chapel gate might be able to assist you further here?
10, You would need to clarify your locker question, the typical 91 model did not have a switchable 'locker' on the front or rear axle, I have heard about them but have never seen one, I am convinced there is an element of confusion here by those not familiar with the system? You will have a centre lock which works within the transfer box, but in general the 80 is full time all wheel drive. or part time, there is little to be gained by the part time system, they were simply cheaper to purchase than the all wheel drive system, fuel savings have been proven to be minimal if any at all, and there is talk of wear on the drive line being reduced, again more speculation for sure. Those that have paid out a lot of money to do the conversion wold never 'fess up' that there was no gain.
I would say to make questions easier to answer you check out exactly the model combination you have, for example does it have rear drum brakes, always a good sign of an earlier model, AC in the back of a 94 body would normally be a Japanese import, adding that you have a speedometer in km's? The chassis number should be on the chassis rail behind the front right hand wheel, this will determine the chassis year and make purchasing parts easier.
Regards
Dave
feels like its an old friend. I am quite surprised on how the familiar the car seems.
