nibbo Posted September 3, 2014 Report Share Posted September 3, 2014 Hi guys, When I am driving my TR7 in slow moving traffic say 20mph in either 2nd or 3rd I am experiencing the car chucking or hesitating if you get my drift sort of back and forth !! Is this caused by play in the diff / prop or is it something to do with timing ? Driving in any other conditions is fine good acceleration etc It also does it when I am deaccelerating. Your words of wisdom would be much appreciated !! :-) Nigel alias Nibbo Quote Link to post Share on other sites
Peter Cobbold Posted September 3, 2014 Report Share Posted September 3, 2014 (edited) Nigel, Assuming its 7 ! - first I'd put some oil in the carb dashpots. If there isn't enough the pistons can flutter making for erratic mixture. Then check the plugs. And if that doesn't cure it, set the spark timing. Peter Edited September 3, 2014 by Peter Cobbold Quote Link to post Share on other sites
nibbo Posted September 3, 2014 Author Report Share Posted September 3, 2014 Hi Peter it's a 2 ltr 7 with a 2nd stage tuned head, I regularly top up the dash pots and the timing seems to be fine, ticks over at 800-900 rpm and dosn't hesitate when I accelerate ! This was a recon engine from S & S so is a good lump, the only difference from the normal set up is I fitted K & N filters, on the original triumph filter there was a plastic pipe that went to the manifold, this was removed and a blank fitted, could this cause a problem ?, there was nowhere on the k&N filters to fit this pipe to. Nigel Quote Link to post Share on other sites
peejay4A Posted September 3, 2014 Report Share Posted September 3, 2014 If the K&Ns flow more air it could be running a bit weak. Quote Link to post Share on other sites
Tim D. Posted September 3, 2014 Report Share Posted September 3, 2014 yes check mixture... Had an Elan that would be a bit choppy at low speed.. turned out is was running lean... Tim Quote Link to post Share on other sites
nibbo Posted September 4, 2014 Author Report Share Posted September 4, 2014 Thanks Guys, I have a Gunson mixture instrument so will check it at the weekend. I have just read a bit in the Moss catalogue in there perfomance page it says "Damper springs for SU carbs, when fitting free flow filters the damper springs should be changed for the heavier 8oz yellow springs" interesting I didn't do that I will order a pair, I did change the waxstat jets for standard fixed jets. Something else to try Nigel Quote Link to post Share on other sites
peejay4A Posted September 4, 2014 Report Share Posted September 4, 2014 If you changed the jets presumably you adjusted the mixture at that time. Quote Link to post Share on other sites
Prefect Posted September 4, 2014 Report Share Posted September 4, 2014 Loose throttle linkage? Quote Link to post Share on other sites
BlueTR3A-5EKT Posted September 4, 2014 Report Share Posted September 4, 2014 (edited) Try stronger throttle return springs, my TR did exactly the same. It was my foot causing the problem. Minus with stronger springs is that the throttle cable eventually, broke first time since fitting in 1976. It now sports a cut down NOS TR5/6 green one I had floating about from years back. I continually imagine I will go back to rod linkage as I have all the parts to do it now. I went to cable as all rod ends were shot when I got the car in 1975, as cable conversion cost virtually nothing using an old bicycle brake cable and a metal plate with cable stop end from a Morris Minor. Cheers Peter W Edited September 4, 2014 by BlueTR3A-5EKT Quote Link to post Share on other sites
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