mossc31 Posted October 6, 2007 Report Share Posted October 6, 2007 I recently experienced a intermittent problem with my 4A. Initially I thought it was ignition so I checked everything including replacing the condenser, then I thought fuel so stripped and cleaned the carbs but it still persisted so I went back to ignition. I eventually tracked the problem down to a loose connection on the low tension terminal in the distributor. Everything is now back in place and the car starts and runs well and the revs pick up quickly when the throttle is opened, carbs are balanced and the timing is about 15 BTDC. My problem is on the move the car seems to lack any grunt, it pulls away smoothly but without any gusto and is happy at 70 but reluctant to increase speed when I open the throttle. Before the ignition problem the car was running just fine. All suggestions gratefully received Chris Quote Link to post Share on other sites
johnny250 Posted October 6, 2007 Report Share Posted October 6, 2007 I recently experienced a intermittent problem with my 4A. Initially I thought it was ignition so I checked everything including replacing the condenser, then I thought fuel so stripped and cleaned the carbs but it still persisted so I went back to ignition. I eventually tracked the problem down to a loose connection on the low tension terminal in the distributor. Everything is now back in place and the car starts and runs well and the revs pick up quickly when the throttle is opened, carbs are balanced and the timing is about 15 BTDC. My problem is on the move the car seems to lack any grunt, it pulls away smoothly but without any gusto and is happy at 70 but reluctant to increase speed when I open the throttle. Before the ignition problem the car was running just fine. All suggestions gratefully received Chris Handbrake stuck on?! Did you adjust the timing or is it as before? advance it a bit to see? john Quote Link to post Share on other sites
gwr Posted October 8, 2007 Report Share Posted October 8, 2007 A bit of granny sucking eggs here - are both ends of the pipe to the vacuum unit attached and are there no leaks? Possibly the bob-weight springs (deep in the bowels of the distributor) have become detached or are broken. This would result in a lack of pick-up, but would probably also be associated with some lumpiness or hesitancy under anything more than very gentle acceleration. Quote Link to post Share on other sites
Ade-TR4 Posted October 8, 2007 Report Share Posted October 8, 2007 Hi I think you'll need to retrace your steps and ensure that each item you have replaced is A) installed correctly, working properly. It does indeed sound timing related and may be worth advancing/ retarding the ignition until you find a sweet-spot with no pinking. Good luck Adey Quote Link to post Share on other sites
67_gt6 Posted October 8, 2007 Report Share Posted October 8, 2007 How obvious should it be to the ear when a TR is pinking? I know what it sounds like on a modern engine if you lug it in too high a gear, but I find it very difficult to tell if the TR is doing it because there are so many other noises going on, not least of which is the exhaust which can sound a little like a VW Beetle at times. Andy Quote Link to post Share on other sites
kob666e Posted October 8, 2007 Report Share Posted October 8, 2007 How obvious should it be to the ear when a TR is pinking? Andy, it will probably sound like a tin of nails!! Thought it was timing chain rattle until I got my timing right, made a hell of a difference in power output. Keep adjusting the timing and driving up a hill in top gear from 30 mph. After a few goes you will soon know what it sounds like. Justin. Quote Link to post Share on other sites
marvmul Posted October 8, 2007 Report Share Posted October 8, 2007 Ignition advance is one of the possibilities : with a stroboscopic light you can check the advance over the whole rpm range. Maximum total advance for a TR4 is about 30 degrees, not more that 32° in most cases. If you don't have a stroboscopic light, you could advance the ignition to 25° static and see if the acceleration has improved. Of course listen for pinking : back off if severe pinking is occurring. Another possibility is the camshaft : maybe some of the lobes are rounded off : the lobes are case hardened : if the thin hardened layer is weared off, the nose of the lobe(s) will wear very quickly, after 1000 miles or something like that. You can get an idea of the lobes by measuring the max lift of the valves with a vernier caliper or simply a measuring staff, holding it vertically along the valve caps and measuring the difference in closed and max. openend position of the valves. When the sump is removed, you can inspect the lobes for damage. Can it be general wear? A compression test is useful, a cylinder leak test is better. Quote Link to post Share on other sites
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