jonnie_r

By open do you mean assembly extended or retracted? After having a google and checking photos, at rest they seem to all be retracted. I managed to get the assembly to move by brute force, so extended it slightly, then refitted it. The idle is now at about 750-800, so I'm guessing that is where the fault would lie. The idle hasn't been right for a while, even with it connected to the MS2, the idle would never change from warm up to normal temp. I am using the standard 4.6 plenum. Thanks for the reply I am going to order a new valve and see what happens. It is quite possible the valve was done for as the car I got the engine from had been stood for about 18 months.

I'm having a problem with idle on my MS2 setup on my 4.6, basically it's running about 1500rpm, sometimes creeps up but generally doesn't drop. I've had the idle valve unplugged and nothing has changed. I've removed the idle valve today and there seems to be very little movement in it(maybe about 1mm). Would I be right in assuming that it is fubared? The coil also buzzes nicely when I plug it into the MS2 connector with the ignition on, which I take to be a sign that it is drawing current but not doing anything.

Took it back up on Wednesday and the ppm was under 100 but the CO was around 5% AFR on their machine was about 13:1. Back up again today after dropping the fuelling around the level that they test at. Will take laptop up as well so hopefully can make changes and get it sorted.

Cheers for the pointers, I'll get out and play with the fuelling when it stops raining here.

Ok, so I finally managed to get the disco MOT'd to check it over and see if it was worth throwing more time and money at. On the whole it wasn't too bad, a couple of lamps and the ABS light is on. The main thing though is mixture and to be fair I haven't had much time to get playing with my MS setup, other than getting the engine running and sorting out TPS issues. Attached is the test sheet, and it looks to me that it could be a case of running slightly lean? My disco is a 95 so is running cats, which I suspect are knackered as the right hand bank has a rattle in the exhaust and I'm not sure my lambda sensors are working properly either. I have bought a new one off Nigel to fit but as yet haven't got round to it. Am I going to be better off replacing the Y piece with the cats and starting from there? Is there anyone local to me, near Tadley, who has had a bit more experience with MS than I have?

I've recently done this one a 4.6 GEMS, I just used the plug on the loom, using an MS2. All is working fine, if you have the GEMS ECU connectors still attached the pin outs for the ignition coils can be found here http://www.rangerovers.net/forum/7-range-rover-mark-ii-p38/44978-lucas-gems-engine-management-ecu-pinout.html

Excellent, thanks for the help guys I'll get on and swap it over asap now.

Yes but there is a port, highlighted below, and when I blow on it air comes out of the port for the idle valve

Having recently fitted a 4.6 engine as my old 3.9 was knackered with liner issues, I refitted the 3.9 plenum on top, which I now realise was a silly idea as the TPS is on it's way to failure and they are a ridiculous price new. I still have the 4.6 plenum, and as I am using a MS2 ecu changing the wiring doesn't pose a problem, my only issue is where does the hose for the idle valve go to?

Here you go, hope this helps

Yes post 95 is slightly different I think, sorry I didn't see you post last night. I'll do it when I get home, but might be later as have my kids to drop back and the stepson to collect. Jon

Just make sure you have the right USB lead, it's not the standard type A rectangular on the serial converter by the looks of it, you would need a type A male to type B male. These leads are quite often used on printers and other USB accessories.

In terms of leads, you would probably be best off just buying a 9 way to 25 way RS232, and get each end to match the gender, the 9 way would then plug into your USB converter and hopefully Bob's you uncle and Dick's a close relative. RS or Maplin would do these, or I suspect Fleabay. The diagram on the last post of the thread you linked to gives you everything you need to make your own cable though

No problem, thanks for sorting them sooner than I could If mine are still needed just let me know and I'll sort them.

No problem, I normally get back around 6ish so will sort it then. Jon

I have a haynes manual at home, so could scan in the relevant pages later if you wanted. Just put MS on mine, but I took out the complete harness and ECU as I was fitting a 4.6 from a RR, also moved the fuel relay and load relay into the engine bay. What age is your disco as there was a change in wiring around 1995. Jon

The device fridge has shown is a USB to rs232 converter, a USB lead connects at one end from your PC, magic happens in the ftdi chips, and it comes out of the 9 pin D shell as rs232 to allow your PC to connect using that protocol. It requires drivers to be installed but works very well. The Easysync stuff I use is probably almost identical inside. RS232 can work over just three wires depending on the implementation.

I use these guys for all my USB/RS232/RS485 stuff http://www.easysync-ltd.com

I hadn't even looked at the 4.6 plenum closely, as I never intended to use it, but I can now see I've been an idiot and should have used it all along............. If I fit the 4.6 plenum, I presume the set up for the connections would be similar, as the stepper has 4 pins, and then I can just select my idle valve type in the MS config software. Thanks for pointing out my stupidity Fridge sometimes the easiest things get overlooked.

Apologies, yes I have an MS2, on a 4.6 GEMS engine, with GEMS coil pack and the plenum from my old 3.9 to allow me to use the idle air control. The calibration changes as you blip the throttle, so a new TPS is called for judging by the answers I've received. I would prefer new as I've been caught out with used stuff before that was supposed to be ok. Jon

The throttle mechanism is functioning fine, I've tried the cable slack and with just a little bit of tension on it. I'll look at the TPS wires though I think the TPS is actually knackered. Cheers. Lol, I guessed it wasn't right. So I need to either replace the TPS or fit the 4.6 plenum along with the idle kit. Thanks Nige. Thanks for the info Cheesy, I've still got all the parts from the top of 4.6 and the TPS connector is still on the engine loom, so may look at going down that route. Jon

Thanks for the welcome, I've been here a while reading bits and pieces. I took my knackered 3.9 out and put a 4.6 tophatted GEMS in my disco. Took me about 6 months of an hour or two here and there but anyway now running. Back to the problem. It reads anywhere from around 480 to 570 at the bottom level and around 900 at the top. I've calibrated and recalibrated but it does seem like the TPS is knackered as it is never the same every time, unless I've got it connected wrong, but I don't think I have. Jon

I have my MS setup running, but seem to have an issue with the TPS. It is a bit all over the place, and the calibration point always changes. One minute it will be reading -10% or more then a quick flick of the throttle and it will be at 15% or so. I'm guessing that the TPS is fubared, and with disco 1 units costing £100, I was wondering how easy it is to swop the idle system from my 3.9 plenum on to the plenum for the 4.6 engine that I recently fitted. Is it worth it or do I just fit PWM control? The engine is running and I've managed a few drives in it, but with the TPS seemingly somewhat erratic it's hard to get everything set properly.