MJ Posted September 20, 2004 Share Posted September 20, 2004 Car is a 1987 1.7 S/Sprint 5spd de-dion, std tune. Problem is poor / rough / hesitant running after car has been used for about 20 mins +. Car always starts on 1st or 2nd turn, idles well at 1000rpm (I've recently balanced carbs) and generally runs well for a few miles. Then after 20 mins or so & usually after some hard acceleration, the car gets all lumpy, won't rev cleanly or beyond about 4000rpm, and power noticeably tails off, so much so that I'm reluctant to overtake even slower moving tin-tops. I've put a new set of leads on & changed the plugs. I've also removed the fuel feed into the front carb and turned the engine over (as advised by RK), so I know fuel is getting through, albeit, the rate of flow seemed a little weak - I was expecting a torrent and a full marmalade jar in a couple of seconds...!!! So, there you have the symptons. Any suggestions as I'm now getting seriously frustrated with driving a bright red 7 and having to think long & hard before I pass Mrs.Miggins in her Micra 1.0. Ideally I would like to resolve myself, as even running an old X/Flow is seriously stretching the old purse strings (get married this Saturday and thus far there's been no mention of selling that "bloody little car that you're always having to mend"...). All suggestions gratefully received. Link to comment Share on other sites More sharing options...
Big Brother Posted September 20, 2004 Share Posted September 20, 2004 Just a guess but try swapping out the coil. It could be breaking down a little as it warms up. Steve Se7en-Up! It'S NOT Green! Link to comment Share on other sites More sharing options...
Manxseven Posted September 20, 2004 Share Posted September 20, 2004 Mike, as it's a X/Flow, after 20 mins of running you'll find it's need filling up again 😬 😬 😬 Best Wishes on your Marriage. Simon Emmens Caterham and Pussy Photos here 😬 Link to comment Share on other sites More sharing options...
martyn_heesom Posted September 20, 2004 Share Posted September 20, 2004 If you have the standard points ignition system, it could be the condenser. I had a similar problem a few years ago (lack of power after running for 20 minutes or so, but would idle OK) that was caused by this. Link to comment Share on other sites More sharing options...
MJ Posted September 20, 2004 Author Share Posted September 20, 2004 Martyn - It runs an electronic ignition - Aldon Igniter, so unfortunately not likely to be coil - a shame as it would have been a cheap fix Steve - I take it you mean the coil itself??? I've already changed all the leads inc. the coil lead. So do coils themselves actually break down over time??? And are my symptons characteristic of a faulty unit??? Thanks Link to comment Share on other sites More sharing options...
Peter Taylor Posted September 20, 2004 Share Posted September 20, 2004 Is it fuel vapourisation? Check that the fuel hose runs are correct and are not close to or contacting anything hot on the engine. Link to comment Share on other sites More sharing options...
Big Brother Posted September 20, 2004 Share Posted September 20, 2004 MJ, just a thought. I had a coil on a Mini fail once. Symptoms were rough running at high revs after about 15 mins of normal running. Only found the problem after changing almost everything else (plugs, points, dizzy cap etc) Do you know anyone who could lend you a suitable coil for a day, just to see if its the culprit? Steve Se7en-Up! It'S NOT Green! Link to comment Share on other sites More sharing options...
MJ Posted September 20, 2004 Author Share Posted September 20, 2004 Will check fuel lines tonight. Will also try to beg/borrow/steal a suitable coil to check this out. Is it a std Ford part or is it Caterham specific??? Link to comment Share on other sites More sharing options...
Nigel Riches Posted September 21, 2004 Share Posted September 21, 2004 Do you have an electric fuel pump? or the mechanical item on the block?, is there a filter in the fuel line? this could be blocking after the fuel has flowed for a period of time, then when the flow ceases, the filter contamination falls, drops off the filter surface, and flow will resume, and so on, just a few thoughts, Nigel. 1982. 5 speed, clamshells. B.R.G / Ali. The True Colours. Link to comment Share on other sites More sharing options...
MJ Posted September 21, 2004 Author Share Posted September 21, 2004 Thanks for all your thoughts. Probably won't get a chance now to spend much time on her (the 7) before the big day, so will address potential fueling issues (vapourisation, blocked filter) and coil when back from honeymoon. Will update this thread in due course Link to comment Share on other sites More sharing options...
Mr Locust Posted September 21, 2004 Share Posted September 21, 2004 Check if it's a ballasted coil being run without a ballast resistor. The points get a bit warm and floppy! By the time you strip them out they have generally cooled down. Also check the fuel tank breather...... Ian Green and Silver Roadsport 😬 Link to comment Share on other sites More sharing options...
MJ Posted September 21, 2004 Author Share Posted September 21, 2004 Ian Would I still have the ballasted coil / resistor with elec ignition fitted??? Or would this not be an issue??? Link to comment Share on other sites More sharing options...
xflow7 Posted September 21, 2004 Share Posted September 21, 2004 I'm no expert, but just a thought here. Have you checked the valve clearances? Maybe they're set slightly on the tight side, so when the valve gear gets all warmed up and expands the valves aren't closing completely. Maybe a long shot, but worth checking I'd suppose. Dave Link to comment Share on other sites More sharing options...
Leadership Team Mcalvert Posted September 21, 2004 Leadership Team Share Posted September 21, 2004 Sounds like the symptoms which I had a couple of years ago on the way to Le Mans. Turned out to be the coil as suggested above. A replacement from a French Scrappie cleared the problem for good! Michael. Link to comment Share on other sites More sharing options...
Mr Locust Posted September 21, 2004 Share Posted September 21, 2004 MJ probably worth checking the spec of your electronic ignition system. That should indicate whether a resistor should be used. Really low tech check; is the coil hot when it starts to play up..........? Stands a good chance that it's taking too much current if it is. Ian Green and Silver Roadsport 😬 Link to comment Share on other sites More sharing options...
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