320touring Posted February 3 Author Share Posted February 3 On Thursday this week, I took this along to an LPG specialist. He was picked because I saw he did a lot of El-Grand work, and those tubs are a difficult thing to do well. En route, I stopped for a high powered exec luncheon The chap was extremely pleasant, all the tools on a tool board, unit tidy and a MK2 Mondeo 2.0 petrol in the corner as a tinkering project. So far so good! I brought the car in, and he set up to read it. The car has a top spec AC Stag sequential injection system. As such, he was able to attach a Bluetooth Dongle to the LPG ecu. All a fair bit fancier than the old single point systems I have had before. The LPG ecu is piggy backed onto the main ECU and uses it's signals for airflow, pedal demand/throttle body positioning and spark timing. Looking at the logs for when the system was last checked/serviced, it was last Accessed on the day after it was fitted in July 2019. The car has done about 70+k miles since then.. The first thing we noticed was that the short term and long term fuel trims were all over the shop. His suspicion was that the AFM was not generating a valid signal. He suggested that at idle, something at 4L should be registering between 4-5grams of air per second. As we can see, It's only registering 1/10th of that. At this point, he said he was not prepared to try tuning the LPG until the car was running correctly on Petrol. I said I totally understood his position, and that it seemed a most sensible course of action. He asked what symptoms I was experiencing - I explained the issues with it stuttering/ delayed response. He decided to try and run a diagnostic program to check the LPG injectors. The ECU has the ability to add additional flow to each injector to balance the fuelling ( to account for wear/contamination from the oil/lubricant fraction used in the LPG) The ECU can add up to a maximum of 25% additional flow. So the lower the number in the table the better. The results? So injectors 2/4/5 are gubbed, with 3/6 showing some wear. This was not entirely unexpected given the lack of servicing or maintenance since it was fitted. Injectors are not too expensive and his costs for fitting/mapping the LPG seems very reasonable. He took a look at the fuelling curves and found another issue. The blue line is the petrol curve, and the green is LPG. The way this was mapped when installed has made the LPG much richer - add in the failed AFM and then it's easy to see why the LPG setup was not smooth. He pulled the LPG fuelling back a touch, and the car is significantly more driveable. Now to find a replacement AFM... grizgut, beko1987, 24vdiamond and 11 others 14 Link to comment Share on other sites More sharing options...
320touring Posted February 12 Author Share Posted February 12 Looks like ATS yer water pump leaking on the XJR then. Stopped it outside the house and gave it a good rev. This is what came out. New pump not too expensive and likely explains the squeaking noise too. Have a new belt ready to fit Supernaut 1 Link to comment Share on other sites More sharing options...
320touring Posted February 19 Author Share Posted February 19 As per @Broadsword's recommendation I have changed the spark plugs on this today. These are the recommended plugs. They are also a common lawnmower sparkplug, so ideal for a big tractor like this🤣 They were £13.30 for 6 delivered. I checked each of the coil packs and they seemed ok, but I may consider fitting new ones If they can be found at reasonable cost. Overall, I'm not seeing too much to worry about. As @jaypee knows, I absolutely adore* changing plugs in multi valve heads... Anyway, first step was pull off the coil pack cover You can see the replacement coil fitted to #2 that seemed to help running. All the plugs came out ok, but we're certainly not in the first flus of health, here's #6 Vs a new one And counting down... 6 5 4 3 2 1 Dyslexic Viking, Saabnut, loserone and 3 others 6 Link to comment Share on other sites More sharing options...
Broadsword Posted February 19 Share Posted February 19 Those spark plugs look fairly typical for a LPG car. They tend to look rather lean and a bit singed, so definitely cheap insurance changing them. This car is rather growing on me. Dibs please when the time comes. I covet thy headers! jaypee and 320touring 1 1 Link to comment Share on other sites More sharing options...
320touring Posted March 3 Author Share Posted March 3 This is now at the tame mechanic for a waterpump, thermostat and a new belt for the pump/alternator. It'll also be getting a good look over for the identification of a couple of knocks and a general once over.. Can't wait til it's back! Broadsword, dome, Dyslexic Viking and 1 other 4 Link to comment Share on other sites More sharing options...
hairnet Posted March 3 Share Posted March 3 39 minutes ago, 320touring said: identification of a couple of knocks stop getting excited 320touring 1 Link to comment Share on other sites More sharing options...
320touring Posted March 14 Author Share Posted March 14 This has been quite the nightmare for @Mk2 Craig. I'd supplied a new waterpump - the impeller half that bolts onto the housing on the block. Aluminium housing, steel bolt. A love story as old as time... In the end, the decision was taken to pull the whole waterpump assembly off and then sort it. Broken bolt removed and hole re- tapped and it was ready to go back on.. Or not.. Grim. This level of corrosion would have meant the pipes wouldn't seat properly and would be likely still to leak. Luckily, your man can drive a wire brush! It was assembled and refitted. Next up was the thermostat. Ah, we've been here before.. it was all cleaned and ready to be refitted. A question for the assembled company - "Who would sell a thermostat without a gasket?" Answer - Berkshire Jag Spares. Handily @Mk2 Craig is into his arts n crafts too! With everything refitted, the new drive belt was applied and supercharger belt refitted too. All in all, a top job - I'm glad I didn't tackle it myself. There is about 9hrs of labour in this, and that was with access to a ramp. Whilst it was up in the air, I'd asked for the steering to be looked at - it felt a bit vague.. Good news is it has had a rack! Bad news was they had used this bolt to 'secure' the knuckle to the rack Consequently, the knuckle/rake interface was as tight as putting your dick out the window and fucking the night... A new bolt was fitted, and with actual contact betwixt rack and column, direction changes are reported to be much more controlled. Many thanks to @Mk2 Craig for all the graft and exceptionally reasonable price - can't wait to get it back! goosey, mk2_craig, Sunny Jim and 7 others 10 Link to comment Share on other sites More sharing options...
320touring Posted April 4 Author Share Posted April 4 Took this to the unit last night. Filled it up with LPG on the way (after about 20miles drive). It's now got a huge dead spot (on both LPG and Petrol) when you go past 1/4 throttle. @Broadsword any ideas? In addition, it looks like it has sprung a coolant leak near the wiper motor, so the low coolant light came on again. It was a fun 120 miles whilst it worked! Dyslexic Viking, JMotor, Supernaut and 1 other 4 Link to comment Share on other sites More sharing options...
Broadsword Posted April 4 Share Posted April 4 1 hour ago, 320touring said: Took this to the unit last night. Filled it up with LPG on the way (after about 20miles drive). It's now got a huge dead spot (on both LPG and Petrol) when you go past 1/4 throttle. @Broadsword any ideas? In addition, it looks like it has sprung a coolant leak near the wiper motor, so the low coolant light came on again. It was a fun 120 miles whilst it worked! In situations like this I would start by thinking what could go wrong at the point of replacing the water pump. It seems more than a coincidence you sprung a coolant leak and got running problems as soon as you replaced the water pump. The fact that the problem persists on both fuels I suppos rules out a fuel system fault. There are a couple of easy things to check. One is the ECU temperature sensor. They give strange running issues when faulty. I assume the cooling system has been poorly maintained since you mention the missing gasket on the thermostat. You have now been in there and shook things up. If there is a lot of crud in there, maybe it could affect the ECU temperature sensor? Same goes for the leak, which will be near the coolant pipes near the heater valve no doubt. New water pump, change of coolant, shake things up and now you have a leak. Was there lots of corrosion or evidence of stopleak used in the system? Another thing to check, is there a flatspot at all times or is it only with the engine running at operating temperature? When was the crank position sensor last changed? They can sometimes fail slowly, leading to strange running issues. It's worth having a spare at all times anyway because you are stranded if it fails. Coprolalia, 320touring and mk2_craig 3 Link to comment Share on other sites More sharing options...
320touring Posted April 4 Author Share Posted April 4 Thanks! Some stuff to investigate then! Link to comment Share on other sites More sharing options...
320touring Posted April 6 Author Share Posted April 6 We played hint the leak on this today: Got the bastard It was nice and simple* to get off, and no* coolant lost! Bit of a gangly fucker to look at - but is either likely repairable ( @jaypee is the man with the patience to try) or I have a reference picture so I can try to find a spare. mercedade, Dyslexic Viking, beko1987 and 2 others 5 Link to comment Share on other sites More sharing options...
320touring Posted April 6 Author Share Posted April 6 As alluded to above, @jaypee had a go at repairing the hose with self amalgamating tape. Cheers! Before Washed Scuffed Taped Will fit it up when back from holiday - also going to see if I can hunt down a spare. loserone, Sunny Jim, Broadsword and 4 others 7 Link to comment Share on other sites More sharing options...
320touring Posted April 27 Author Share Posted April 27 After Yodel took a WEEK to deliver the 48hr package, the new hose had finally arrived. Here it is! Looks great! But, wait a minute.. it looks longer?! What's going on here? Time to investigate. First up, where the old hose joins: I doubt Jag would have shelled out on copper joiners for hoses.. It then disappeared under the coolant reservoir The air box and airflow meter had to come out too @loserone summed up the situation It turns out that the original pipe has been spliced into one that goes to the vapouriser, obviously to allow the coolant to heat the LPG so it just becomes PG. I decided big boy pants were the order of the day and set to cutting the new pipe. I then refitted it and filled the hoses with about 4L of water to ensure that there was not a massive air lock. Luckily, @captain_70s turned up at this juncture and was available to assist. We started it and ran it with the cap off, topping it up until it put the low coolant light off. Then we switched it off, and went to get the oil filter for the Octavia... That was a mistake. Once back we decided to pull out the XJR to bleed it up properly. This was the result: We left it on boil for an hour but still had to jump start it . Once outside it drove about , got to temperature and had toasty heaters. No obvious leaks😍 I'll charge up the battery and double check the coolant when I am next over, but hopefully that's it back in service. Cheers again to @captain_70s for the help! mercedade, Dyslexic Viking, Tickman and 1 other 4 Link to comment Share on other sites More sharing options...
320touring Posted May 1 Author Share Posted May 1 Back over to this today. Coolant all within the system, and it fires up with a jump. It sat quite happily idling away charging the battery - heaters move and hot, no coolant leaks and temp gauge bang on the normal mark. This good behaviour was rewarded with the first wash it had had in my ownership. Many thanks to @davidfowler2000 for the effort on the jetwash. It certainly benefitted from the snow foam Schaefft, Tickman, mercedade and 2 others 5 Link to comment Share on other sites More sharing options...
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