smacsor Posted May 25, 2008 Share Posted May 25, 2008 Hi, My 1985 90 2.5P has an enormous flat spot which means the engine sometimes almost dies momentarily when changing gear or with sudden throttle openings. The Weber carb has been (so say) set up but I'm not sure how well but the inlet manifold and carb to manifold gaskets have been replaced as they were leaking. Are there any adjustments to the carb that a simple chap like me could try in an attempt to eliminate this as the fault makes driving a rather unpleasureable experience? I've read that this can be caused by an incorrect setting on the idle mixture but I've also read elsewhere that this setting would only effect the mixture at idle and would have no effect at driving speeds? Or, and bearing in mind it's 23 years old, should I go the whole hog and replace with a new 32/34 DMTL? Many thanks, Simon Quote Link to comment Share on other sites More sharing options...
Coastcard Posted May 25, 2008 Share Posted May 25, 2008 May also be worth checking the ignition stuff. Can cause similar symptoms. Quote Link to comment Share on other sites More sharing options...
Diff Posted May 25, 2008 Share Posted May 25, 2008 Hi,My 1985 90 2.5P has an enormous flat spot which means the engine sometimes almost dies momentarily when changing gear or with sudden throttle openings. The Weber carb has been (so say) set up but I'm not sure how well but the inlet manifold and carb to manifold gaskets have been replaced as they were leaking. Are there any adjustments to the carb that a simple chap like me could try in an attempt to eliminate this as the fault makes driving a rather unpleasureable experience? I've read that this can be caused by an incorrect setting on the idle mixture but I've also read elsewhere that this setting would only effect the mixture at idle and would have no effect at driving speeds? Or, and bearing in mind it's 23 years old, should I go the whole hog and replace with a new 32/34 DMTL? Many thanks, Simon The symptoms described sound like there is dirt in the float chamber of the carb, or the accelerator pump on the carb is not working. First step would be to try to clean the carb. You can try the 'free tune up' trick which can sometimes clear any debris or blockages: Take the black elbow off the top of the carb and start the engine. Whilst holding the throttle wide open (revving the engine really high), block all the air going into the carburettor with a rag or whatever, briefly, then again and again a few times.This can have the effect of pulling the rubbish out of the jets/float chamber if you are lucky. A carb overhaul kit is about £25 A new carb is nearly £200. Other possibilities includes a failed vacuum advance capsule on the side of the distributor. Regards, Diff Quote Link to comment Share on other sites More sharing options...
smacsor Posted May 26, 2008 Author Share Posted May 26, 2008 Thanks for the advice. I'll give it a go and let you know how I get on! Simon The symptoms described sound like there is dirt in the float chamber of the carb, or the accelerator pump on the carb is not working. First step would be to try to clean the carb. You can try the 'free tune up' trick which can sometimes clear any debris or blockages: Take the black elbow off the top of the carb and start the engine. Whilst holding the throttle wide open (revving the engine really high), block all the air going into the carburettor with a rag or whatever, briefly, then again and again a few times.This can have the effect of pulling the rubbish out of the jets/float chamber if you are lucky.A carb overhaul kit is about £25 A new carb is nearly £200. Other possibilities includes a failed vacuum advance capsule on the side of the distributor. Regards, Diff Quote Link to comment Share on other sites More sharing options...
smacsor Posted May 26, 2008 Author Share Posted May 26, 2008 Ok...checked ignition system - all OK Tried the "free tune-up trick" - unfortunately no better! I'm tempted to bite the bullet and replace the carb with a new 32/34 dtml 6/101 as I can pick one up up for around £150. I have basic mechanical skills but no experience with land rovers or Webers!! Is replacement a simple bolt off bolt on job? I think I'm OK with the idle speed and idle mixture adjustment as long as I can get the bugger running! Thanks, Simon Quote Link to comment Share on other sites More sharing options...
smacsor Posted May 31, 2008 Author Share Posted May 31, 2008 These are probably stupid questions, but I'm a novice so please bear with me! I've just fitted a new Weber which has solved all the previous problems....in fact she runs like a dream now...like a new vehicle!! BUT..the engine is now racing on tickover because the throttle cable is holding off the throttle linkage on the carnb preventing it from fully closing. It's not the idle speed adjustment , its definately the cable. Bot the cable adjuster where it fixes to the carb is at its maximum adjustment. Am i missing something. Is there another way of adjusting the cabe or do I need a new one? I don't understand why its like this now when the new carb is identical to the old one. Also after my test drive , the engine ran on after I switched off the ignition. Its never done this before. Is this related to the first issue or have I got something else wrong? Thanks in advance, Simon Quote Link to comment Share on other sites More sharing options...
disco_al Posted May 31, 2008 Share Posted May 31, 2008 sounds like you need a longer cable, or adjust the tickover screw on the carb (if it has one of course) running on is usually timing related Quote Link to comment Share on other sites More sharing options...
smacsor Posted May 31, 2008 Author Share Posted May 31, 2008 Thanks, I'll try a new cable. I've knocked the timing back a bit as it was pinking slightly under load but it hasn't had any effect with the running on. Seems odd that its only started doing it with the new carb? Any ideas? sounds like you need a longer cable, or adjust the tickover screw on the carb (if it has one of course)running on is usually timing related Quote Link to comment Share on other sites More sharing options...
smacsor Posted May 31, 2008 Author Share Posted May 31, 2008 Sorted!! Checked the plugs and they were white as snow so richened it up and all seems fine now. I can't believe how much better the vehicle is now and I now realise what a pig it was to drive before! Cheers, Simon Thanks,I'll try a new cable. I've knocked the timing back a bit as it was pinking slightly under load but it hasn't had any effect with the running on. Seems odd that its only started doing it with the new carb? Any ideas? Quote Link to comment Share on other sites More sharing options...
Steve Warman Posted June 1, 2008 Share Posted June 1, 2008 Sorted!!Checked the plugs and they were white as snow so richened it up and all seems fine now. I can't believe how much better the vehicle is now and I now realise what a pig it was to drive before! Cheers, Simon Hi, I'm a a novice as well so it's my time to ask another stupid qestion but are you driving a petrol model and what plugs were white? Thanks Steve Quote Link to comment Share on other sites More sharing options...
smacsor Posted June 1, 2008 Author Share Posted June 1, 2008 Hi Steve, Welcome to the novice sub-group!! The spark plugs were white which indicated it was running far to lean and this was causing the running-on. Without access to the right specialist equipment I was setting up the carb by trial and error. Once I had it running roughly at the right fuel mixture, the running on stopped and she runs like a dream now and the spark plugs are a nice light brown colour. Mine in a 1985 2.5 Petrol. Have you got a similar problem? Cheers, Simon Hi,I'm a a novice as well so it's my time to ask another stupid qestion but are you driving a petrol model and what plugs were white? Thanks Steve Quote Link to comment Share on other sites More sharing options...
Steve Warman Posted June 1, 2008 Share Posted June 1, 2008 Well I've had a few problems with my carb, including fuel spilling out of the float chambers, pretty much my own doing, so I changed the carb to a second hand weber andnow it runs but it does run over a bit bit runs lumpy at the best of times and does soemtimes stall for no apparent reason. the idle will either hold out or drop off enough for it to stall. I don't really have much experience with the inner workings of a carb, it's beyond my capability at the moment. Quote Link to comment Share on other sites More sharing options...
airportable Posted May 27, 2017 Share Posted May 27, 2017 Hi every one. I just bought a new 32/34 to fit my land rover, but there was't any fiting instroctions in the box. so my stupid cuestion is, how do i connect it? Can't find any fiting diagrams on the net. Is it that simple? Only me stupid. Thanks Quote Link to comment Share on other sites More sharing options...
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