Pete12345 wrote:

Surely the easier method is to make sure the correct engine type is selected in the BECM. The BECM converts the analog reading from temp sender & fuel sensor to a value from 0-255, which then drives the gauges. It's more likely the A-D conversion changes than the gauge settings ?

But then there are many different instrument pack part numbers

My suspicion is the becm simply measures the voltage and sends the signal across to the cluster as a 0-255 digital value. It doesn't do anything to the reading other than measure and pass it on.

The cluster takes that digital value and applies a lookup table for the guage deflection.

The reason I suspect this is the becm diagnostic doesnt actually show the temperature, it only displays the digital value.

I tried resetting the gems engine type and writing settings again just incase doing that would somehow pass it on to the cluster, but it didn't make any difference.

is the fuel pressure regulator manifold referenced? If so its normal that it will fluctuate around.

The aim is to maintain say 3bar across the injector. If the manifold is under 0.5bar of vacuum, the pressure in the rail will drop to 2.5bar. If there is 1 bar of boost in the manifold, the pressure at the rail will increase to 4 bar.

Returnless systems are not referenced like that, but the ECM can alter the fuel pump speed via PWM, so you may also get similar variations in pressure as the pump adjusts its speed to meet demand.

I'd be looking at the three odd cylinders and figuring out whats going on. Might be worth getting the injectors properly ultrasonically cleaned and tested? Its usually fairly cheap and can be a good thing on an older engine anyway. A free test would be to move the injector to another cylinder and see if the issue follows.

19 is pretty good.

I drove mine home 40miles the other night on petrol as the LPG had run out. Reset the trip computer when i left mums as i wanted to know what it was going to have cost me on petrol and did most of the 40miles on cruise at 70, MPG was showing 15.5 when i got home. 😭

From googling online the Thor dual sensor and the GEMS engine sensor both use the same thread. So it should screw right in there.

Just need to see if the Engine part of the Thor sensor uses the same resistance range as the GEMS one. I only have one datapoint for the GEMS engine sensor currently: ~4.5k at 5c

However the Thor sensor was around 2.8k at 20c, and some googlefu suggests that sensors reading ~2.8k at 20c will often read around 4.5k at 5c

I've put it in the fridge and will measure it tonight to get some more points to confirm. But we may be in luck and i can just fit the Thor sensor in place of the ECM one, rewire and job done.

Yeah I could have gone that route, but if it went wrong I'd be staring at two broken clusters 🤣

I figured swapping them would be easier.

Just need to figure out either a matching sensor that will fit the 1/8" NPT hole, or a way of attaching the Thor sensor to the gems manifold.

Okay additional data points

Fuel guage behaves the same way when I plug the original cluster back in. I guess the becm will dial itself in once I'm driving.

Temp guage I suspect there is a calibration difference between the gems and Thor engines.

Measured the sensor on the engine at 150ohms at around 50c and according to some online resources measures about 600ohms at room temp.

Measured my Thor sensor and it's at 150ohms around 80c and ~1200ohms at room temp.

Some months ago while in the local U-Pullit i happened across a late model P38 with a updated cluster.

The guage faces have a green background and the legends etc are all a bit more modern, so i bought it.

Finally went to fit it today, and after sorting some niggles (airbag warning light/message due to a missing bulb) and syncing the odometer, it all seemed to be working, except the two small guages.

The fuel guage seemed to display 1/4 tank. The petrol tank is nearly empty and with the old cluster the light was on and the guage was just off the red. Though at various points it did correctly display "fumes" as it should, it also at various points returned to showing 1/4. I took it out for a drive for a mile or so and it slooooowly dropped to the line before the red, however the light didnt come on. I dont know if it would have eventually sorted itself out. When i got back, i cycled the ignition a few times and eventually it did show the low fuel light, but after checking some things with nanocom, it went back to showing 1/4 tank again....

The test drive also highlighted a second issue. Once it warmed up the temp gauge pinned its self round against the right hand side and the red warning light came on. Checked with nanocom, and the ECM was reporting 93c as normal. Does the temp sensor perhaps differ between Gems and Thor? Any way to alter the calibration?

The shiny areas are heavily grooved and there are other deep gouges all over the shafts. I would guess there is 0.5mm of wear on those shiny areas. There is also ridges from where the pedestals sat.

From reading online it seems bits of debris from camshaft/lifter wear etc gets embedded in the soft aluminium of the rocker and eats thru the shaft. So reusing those rockers on new shafts is also a no-go.

Problem is it seems aftermarket rockers are also complete junk 🙁

I think these might be knackered 😂

I've got a pair of rocker shafts from my spare engine which I'd like to disassemble and clean to go back on the heads before install them to the engine in the car.

Then I wondered, do these parts need to marry up with the original components? I don't have the pushrods from the spare engine, and the rocker shafts have been mixed up so aren't going back on the original heads either...

Assuming I can still use them, is there anything specific I need to check or measure to check for wear?

Yeah I'll need to dig the bits out. Headgaskets will be happening soon so ideal opportunity to do some comparison.

The crank pulley is the same as is the crankshaft itself? So the lower pulley is in the same place on both engines?

I cant see how the alternator can therefore operate in a different plane?

The tensioner arrangement is different, but the tensioner itself seems to be the same part, the Thor just gains an additional idler (presumably for more belt wrap?)

So a thor alternator+bracket+tensioner should work on a GEMS unless it clashes with something?

Does the Thor use a different crank pulley or something?

I actually have a full Thor engine spare but the alternator was snagged before they took it out the car, so I have the brackets but not the alternator itself.

I've always felt my alternator lacking. Voltage will sag right down when using heated screen for instance.

Had a look just now and its a Denso 076334-1353 unit, which seems to be 100A from what i can find online.

The Thor units seem more powerful, 150A versions are fairly readily available on ebay... are there any other options for Gems?

Do you know if a Thor bracket will fit a GEMS engine (and still work with the other anciliaries)?

Not seen th p38 one specifically, but a lot of cars have the autobox cooler integrated into the rad end tanks.

Petrol p38 have a separate autobox cooler, but perhaps they've integrated it in the diesel to save space or similar.

Left the window open in the rain for the second time in a week...

Drivers side this time, just to even it out
😭

https://i.imgur.com/L9ljrvR.jpg

Could this be the culprit?

I've always just bought whatever was cheapest from a reasonable brand. Stick with the OEMs for best results and avoid unbranded stuff unless your just trying to fix something as cheaply as possible to get shot. Sort by price on eBay or autodoc (other vendors available!) and go from there.

I put drilled disks on the A4 (factory fit on certain models so you can get them from the normal aftermarket suppliers and they cost much the same as plain disks.) but they didn't really make any difference, and over time the drilled holes block up anyway. Grooved disks I've always avoided as they can be noisy and increase pad wear.

making sure the sliders and everything are working and the carriers are cleaned up so the pads can actually move makes a huge difference.

Gilbertd wrote:

Yes. If you open the sunshade and tilt the sunroof up, you will see a plastic cover on either side, this slides out towards the back of the car (it's on keyhole shaped holes with pins in them). This will expose the two Torx screws and a couple of small C clips, remove those and lift the glass out. To get the sunshade out, RAVE says to open the sunroof and remove the wind deflector before taking the glass out (but I don't remember doing that the last time I took one out). Once the glass is out and the wind deflector off, undo the two screws on one side that hold the runners in place, this will allow it to be moved slightly and allow the panel to come out although a bit of brute force will do it just the same.

Did this today.

Glass came out easily, there's a small gutter at the rear that needs to come off too.

Pushed up in the middle and the panel popped out. All four clips came off intact too.

Recovered it and decided to trim the material away from the runner area but wrapped around the front and back.

Reinstalled with a similar bending as removal, helped to have an extra pair of hands steadying it while I fitted the clips back on.

Lubed the front pivots as they were stuck too and then put it all back together. Success!

MOT retest tomorrow then I will refit the actual headliner. I think I'm going to get some PU sealant and seal the sunroof up entirely then disable in the becm. Hopefully stem off any future leaks.

i need to sort that on mine ^

except mine seems to be the passenger side.

Currently have a dehumidifier running inside it trying to pull some of the dampness out, its starting to smell a bit.