Don Del Posted May 26, 2012 Share Posted May 26, 2012 I have recently had the SU carbs on my V8 110 Station Wagon fully overhauled (new jets, needles, floats, float needles and seats, etc, etc). The parts were sourced fron Burlen and the work was done by an experienced LR mechanic moonlighting from the local ex Land Rover agent. After the work there was a marked improvement in performance and fuel consumption but with one niggling problem. The vehicle goes like a train in a straightline both on the flat and uphill but with the accelerator flat to the floor in second or third any bend of more than 30-40° in the road results in a marked loss of power. As soon as the road staightens out everything returns to normal. The engine never cuts out completely and there is no backfiring. I have checked for loose electrical connections but everything appears OK. I have a feeling that the problem is in one or other of the float chambers, possibly a needle valve stivking open or closed, and intend stripping the carbs next week to check. In the meantime any suggestions as to what might be causing this problem would be welcome. Quote Link to comment Share on other sites More sharing options...
Spearos Posted May 26, 2012 Share Posted May 26, 2012 Could the float heights, if set too low cause this problem? I'm sure a grown up will be along soon with a better answer/suggestion.... Quote Link to comment Share on other sites More sharing options...
Tanuki Posted May 27, 2012 Share Posted May 27, 2012 It may sound strange but - check the routing of the HT leads. I've experienced a RV8 or two where the HTleads were a bit floppy and moved about under cornering - causing 'crossfiring' between pairs of leads. A weak spark was getting to some cylinders at the bottom of their intake stroke, causing all sorts of badness. I've even seen this be bad enough to cause a blowback and blow all the oil out of the SU dashpot on one bank of cylinders. --Tanuki. Quote Link to comment Share on other sites More sharing options...
Don Del Posted May 28, 2012 Author Share Posted May 28, 2012 Could the float heights, if set too low cause this problem? I'm sure a grown up will be along soon with a better answer/suggestion.... I think you have a point. Watch this space and I will make my findings public when I get around to dismantling the carbs later this week. Quote Link to comment Share on other sites More sharing options...
Don Del Posted May 28, 2012 Author Share Posted May 28, 2012 It may sound strange but - check the routing of the HT leads. I've experienced a RV8 or two where the HTleads were a bit floppy and moved about under cornering - causing 'crossfiring' between pairs of leads. A weak spark was getting to some cylinders at the bottom of their intake stroke, causing all sorts of badness. I've even seen this be bad enough to cause a blowback and blow all the oil out of the SU dashpot on one bank of cylinders. --Tanuki. When the problem first started I also considered the HT leads or the supply to the coil as possible culprits but on checking everything appeared OK and I was unable to replicate the problem with the bonnet up and "wiggling" the HT leads and coil/distributor power supply. Quote Link to comment Share on other sites More sharing options...
Don Del Posted June 1, 2012 Author Share Posted June 1, 2012 Job done! The floats on both carbs were set 8-10mm low. Not only that there was no oil in the dampers, the screws holding the butterflies hadn't been splayed open, one of the needles hadn't been fitted correctly and the hard to get at carb fixing nut on the bottom right corner of the left hand carb hadn't been fitted. All iall very disappointing from a mechanic with 10 years plus experience. I suppose it just reinforces the old adage - "if you want a job done right, do it yourself"! Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted June 1, 2012 Share Posted June 1, 2012 Job done! The floats on both carbs were set 8-10mm low. Not only that there was no oil in the dampers, the screws holding the butterflies hadn't been splayed open, one of the needles hadn't been fitted correctly and the hard to get at carb fixing nut on the bottom right corner of the left hand carb hadn't been fitted. All iall very disappointing from a mechanic with 10 years plus experience. I suppose it just reinforces the old adage - "if you want a job done right, do it yourself"! 10 years ago was 2002, even 20 years ago in 1992 most (if not all?) general cars were fuel injected by that stage. So it takes a long-serving mechanic or a specialist/enthusiast to find someone who knows what they're doing with carbs these days! Glad you got it sorted though Quote Link to comment Share on other sites More sharing options...
Spearos Posted June 2, 2012 Share Posted June 2, 2012 Job done! The floats on both carbs were set 8-10mm low. It now almost sounds like I know what I'm talking about... sometimes! Not only that there was no oil in the dampers, the screws holding the butterflies hadn't been splayed open, one of the needles hadn't been fitted correctly and the hard to get at carb fixing nut on the bottom right corner of the left hand carb hadn't been fitted. All iall very disappointing from a mechanic with 10 years plus experience. I suppose it just reinforces the old adage - "if you want a job done right, do it yourself"! My Mum used to use that saying, and i've come to learn it's so true! Leaving that nut off (probably because it's awkward) says a lot about this 'mechanic' - I trust you won't be using him again! Great news that it's alright now though Quote Link to comment Share on other sites More sharing options...
GW8IZR Posted June 3, 2012 Share Posted June 3, 2012 All real mechanics should have tool boxes full of bent sawn off and ground down spanners :-) Quote Link to comment Share on other sites More sharing options...
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