Shanrad Posted September 5, 2016 Share Posted September 5, 2016 Hi ive got a 3.9 discovery. Any issues with removing the gas setup that could create the vehicle to either running like carp or to not start at all? Ive removed mine and iam having alot of issues with it running like carp or randomly wont start at all. When doing the gas removal we also changed the head gasket. Please help. Its now been a month not going and my birthday is next week and was planning to go camping but if it won't running like it should ill be staying home 1 Quote Link to comment Share on other sites More sharing options...
Arjan Posted September 5, 2016 Share Posted September 5, 2016 V8's love LPG. If the vehicle runs on petrol it is most likely to be an LPG issue. If the vehicle runs poorly on both petrol and LPG you have other problems. Before getting the engine run on LPG it should run perfectly on petrol. Afterwards, you can get the engine to run on LPG. Bon Courage ! Quote Link to comment Share on other sites More sharing options...
Chicken Drumstick Posted September 5, 2016 Share Posted September 5, 2016 Hi, maybe you could add a little more info????? What do you mean by 'gas'? Are you meaning LPG? What exactly did you remove? Why? Did it run ok previously? Why do the head gasket? Quote Link to comment Share on other sites More sharing options...
Shanrad Posted September 5, 2016 Author Share Posted September 5, 2016 Sorry about that Yes iam talk about the LPG. The tank and everything under the bonnet is removed. It didn't run real good on lpg and i was told they wreck the engine so out it goes. The head gasket was wrecked.i was losing water out the exhaust. It was running fine still until we done the gasket and removed the lpg set up. Ever since it was all done it would only start when it wanted to and when it did start it ran really rough. Its got me beat Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted September 5, 2016 Share Posted September 5, 2016 There's a troubleshooting guide for the EFI's in the technical archive, step-by-step. Quote Link to comment Share on other sites More sharing options...
Shanrad Posted September 5, 2016 Author Share Posted September 5, 2016 Whats it under? Just so it doesn't take forever to find it. Cheers Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted September 5, 2016 Share Posted September 5, 2016 Search for hotwire on the page. Quote Link to comment Share on other sites More sharing options...
Shanrad Posted September 7, 2016 Author Share Posted September 7, 2016 Anybody know first hand how to check the maf reading with a multimeter? Iam unsure of how to use this device correctly and what settings to have it on. Ive put the red lead into the vma socket and the black into the one that has no label and turned it onto v 20 setting. I then turned the key on,put the red into 35 on the ecu plug and earthed the black but its reading 11.79 which tells me its definitely not right lol. Any help would be awesome. Iam still leaning this side of the discovery and enjoy learning. Cheers Quote Link to comment Share on other sites More sharing options...
toastkid Posted September 7, 2016 Share Posted September 7, 2016 You have asked this on another thread. Here is my suggestion (again) https://www.2carpros.com/questions/land-rover-discovery-2-2001-land-rover-discovery-2-maf Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted September 8, 2016 Share Posted September 8, 2016 If you're not sure how to use a multimeter I'd suggest having a read up on that 1st before you accidentally blow something up. Quote Link to comment Share on other sites More sharing options...
Shanrad Posted September 9, 2016 Author Share Posted September 9, 2016 Ive learnt how to use the metre now thanks mate. Ive now installed a working air flow metre and the bus turns over perfect but still no fire. This is starting to really do my head in. Any other suggestions? Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted September 9, 2016 Share Posted September 9, 2016 If not firing then I would check the injector wiring, with lpg it is common to cut these and put a relay in line, without the gas switch installed they may simply be disconnected. Other option is they used injector 'emulators' though I suspect you have already removed them... 1 Quote Link to comment Share on other sites More sharing options...
Shanrad Posted September 9, 2016 Author Share Posted September 9, 2016 What are the emulators? We've removed the relays and the joined the wired back up to where they need to go. Was only two wires that needed joining again. Am i missing something? We did have the vehicle running for awhile but never ran properly Quote Link to comment Share on other sites More sharing options...
Shanrad Posted September 9, 2016 Author Share Posted September 9, 2016 And now wont start at all Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted September 9, 2016 Share Posted September 9, 2016 OK emulators weren't in use by the sounds of things Check if you have spark Check if you have fuel Check your ecu has power Quote Link to comment Share on other sites More sharing options...
Dave W Posted September 9, 2016 Share Posted September 9, 2016 Check the feed from the ignition coil to the ECU, there's a wire that comes from the coil and joins into the loom by the MAF sensor connector. If the LPG kit had tapped into that for it's RPM input then it may have been disconnected or disturbed. Without that signal from the coil the EFi system will not inject fuel or run the fuel pump after the initial prime. It looks like a thick black wire normally and can be mistaken for an earth. I've lost count of the number of hotwire EFi systems that this particular wire has rendered dead after some work on the engine. 1 Quote Link to comment Share on other sites More sharing options...
Shanrad Posted September 12, 2016 Author Share Posted September 12, 2016 The vehicle is now running again but still very rough.i had somebody over to help me and they mess with the coil wires when i wasnt around. Its funny that you talk about a wire thats in the maf sensor connector harness. I found an orange and brown wire just chilling on its own so i joined it up to the orange and brown on the maf plug because it had nothing there and was the same color..from what i read its a 12v wire. I had to put an extension of wire in first because it didn't reach the maf. Would this have anything to do with it? There is no wire going to the coil from the maf sensor..its all coming from over the engine. White/green and two white/blue Cheers Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted September 12, 2016 Share Posted September 12, 2016 The hotwire loom uses the same colour code more than once, I'd be very wary of joining random wires unless they've obviously been cut and clearly join up with something. The full wiring diagram is in the tech archive and has been posted before so you can follow the loom. Quote Link to comment Share on other sites More sharing options...
Shanrad Posted September 14, 2016 Author Share Posted September 14, 2016 Ive triple checked that the wire is in the correct location. I love my disco and its one of the best vehicles ove owned but iam starting to wish i never got it ? Quote Link to comment Share on other sites More sharing options...
Shanrad Posted September 14, 2016 Author Share Posted September 14, 2016 I believe I may have found an issue but I am unsure. While the engine is running ive disconnected the AFM but no change in the engine. I done the same to the throttle position sensor amd also no change. Is this something I should look into? Quote Link to comment Share on other sites More sharing options...
Dave W Posted September 14, 2016 Share Posted September 14, 2016 When you disconnect the AFM or the throttle pot or most of the other sensors, the ECU uses a default mode to continue running without them. It's actually more common for a faulty sensor, once disconnected, to make the engine run smoother than the other way around. Did you complete the troubleshooting guide ? That covers off the majority of the wiring and ensures the sensors are in the right ball park. You need to take a methodical approach to fault finding on these engines, using a "scatter gun" approach just leaves you running around in circles, which, from the posts in this topic seems to be what you are doing at the moment. Quote Link to comment Share on other sites More sharing options...
Shanrad Posted September 15, 2016 Author Share Posted September 15, 2016 Ive been doing the troubleshooting guide but so far found no issues. The engine in now running but still running rough and blowing black smoke (not drivable). I guess ill have to go back over it again Quote Link to comment Share on other sites More sharing options...
Shanrad Posted September 21, 2016 Author Share Posted September 21, 2016 Ive gone back over its all again iam still no better off. I just cant understand how its gone from running great to fixing the head gasket and removing gas and now running like this. Ive had mechanics look at it and auto electricians but they cant work it out (none have ever worked on discoverys before though). Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted September 21, 2016 Share Posted September 21, 2016 It's a bit tedious but can you list all the things you've checked from the troubleshooting guide? If it's overfuelling like mad and all the sensors check out, if it's been on LPG a long time I'd look at the fuel pressure regulator being stuck (or possibly just mis-plumbed / disturbed) as my next thought (without knowing if you've already checked that). Quote Link to comment Share on other sites More sharing options...
Shanrad Posted September 21, 2016 Author Share Posted September 21, 2016 Ive replaced and then checked: Throttle position sensor,coolant temp,maf,dizzy and module. The coil,lead and plugs have done 400ks at a guess. Auto electrician checked the spark and said it was good. Everybody thats heard the vehicle seems to think it sounds like its not running on all cylinders. Ive had the rocker covers off again today and everything in turning over smooth in there plus compression test says its perfect. I did have it running a few days ago (still running bad) but now it won't start. Ive had the bus 1 year and never ran it on LPG. Iam getting plenty of fuel i believe. My oil now smells of it so ill need an oil change once again id say Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.