JohnG Posted March 4, 2015 Report Share Posted March 4, 2015 All I read on the forum a while back, that disconnecting the cold start cable at the throttle, leaving the cable connected to the MU, was the way to go. Unfortunately, I have searched the forum, but cannot find the reference Other jobs meant trying this went onto the back burner. As I am close to getting the car out of the garage, can anyone point me in the right direction for reading up on the merits of this move please? Quote Link to post Share on other sites
peejay4A Posted March 4, 2015 Report Share Posted March 4, 2015 As far as I'm concerned as an ex 6 owner there are no merits in not connecting the fast idle cam at the throttle bodies. Quote Link to post Share on other sites
jojim65 Posted March 4, 2015 Report Share Posted March 4, 2015 As far as I'm concerned as an ex 6 owner there are no merits in not connecting the fast idle cam at the throttle bodies. Ah, the double negative ploy to really confuse me... I can say that with both the MU and Throttle body cables set up correctly it works fine for a 1970's car. It certainly isn't up to the seamless cold starting of a modern car but with a little work it can be acceptable. You could always introduce your own fast idle cable so the two work independently. Whether you consider the work involved is in proportion to a cold start and an inch on the pedal till it will run without stalling is up to you. Jim Quote Link to post Share on other sites
peejay4A Posted March 4, 2015 Report Share Posted March 4, 2015 Well if you're good at heel and toeing to keep the thing running as you approach stopped traffic with the engine cold then go for it. Too annoying and risky for me, not to mention embarrassing when it goes wrong. Quote Link to post Share on other sites
Peter Cobbold Posted March 4, 2015 Report Share Posted March 4, 2015 John, Try it. I ditched mine around 1980 and it gave no cold running problems even in winter, subzero. A few blips on the throttle once the oil pressure was up, and away. Mind you I probably had a winter thermostat. Easy to refit if it gives you problems. Peter Quote Link to post Share on other sites
jamesStag Posted March 4, 2015 Report Share Posted March 4, 2015 John, Well for me the fast idle is very useful, and no way I'd disconnect it. What I have done is tweak the fast idle speed such that its about 1,200rpm so the motor's not racing away. Normal idle being about 750. I do find the hot idle does seem to vary a bit and can be 600-900. Have checked and butterflies do seem to shut to a gentle stop (am aware of fag-paper style setup but just balanced them all with a flowmeter and believe that's more important than most other settings) Cheers, J. Quote Link to post Share on other sites
Damson6 Posted March 5, 2015 Report Share Posted March 5, 2015 I struggled to get the MU and throttle idle to work together so have run without idle connected for years without problems, if the MU choke is out I get fast idle anyway. Quote Link to post Share on other sites
Anthony Posted March 5, 2015 Report Share Posted March 5, 2015 I am new to this Forum having just taken delivery of a TR5. Although many years ago I was a TR Register member and have in the past had A TR4A and two TR5's. While owning the latter cars I had no trouble with the cold start. However, on this "new" car it takes two hands to pull the lever/button/knob out and I have to hold it out against the springs of on the MU and the throttle bodies otherwise it simply reasserts itself, which is a bit of a nuisance! This morning, and with some difficulty I located and removed two springs on the throttle cam mechanism. One linked to the other in tandem. Seems to me to be a bit Heath Robinson and I would like to know if anyone agrees that this cannot be right and if not what might be the correct spring set-up or even if they know the part number. I'm not keen to remove the cold start at this stage - I want to get to know the vehicle a bit before I start "playing". The spring on the MU also seems rather powerful so the combination of the three is a bit of a handful. Any ideas anyone, please? Tony Quote Link to post Share on other sites
JohnG Posted March 5, 2015 Author Report Share Posted March 5, 2015 OK This is all part of the grand plan to try and encourage smoother running on start up and when the engine is cold. In persuit of this I have, so far; had the MU refurbished, fitted refurbished injectors, changed thd HT leads, fitted a new air filter, fitted BUR6ET plugs and tweaked the butterfies to balance their operation. I have confidence in Peters advice, so, this weekend the cable will be disconnected. I will leave the cable in place, cable tied to one side, out of harms way, so that I can reconnect it, if need be. I will report back Wish me luck Quote Link to post Share on other sites
jamesStag Posted March 5, 2015 Report Share Posted March 5, 2015 Hi John, OK it certainly can't hurt to try disconnecting fast idle cable, but if your issue is rough running when cold or 'not smooth' I wonder if something else might at fault... Granted I can see you've been through a good list of things. What happens at cold start up? Is it ages to catch, only start on a few cylinders? General missing or something intermittently? My own TR6 seems to be fairly well behaved. If its run recently I just run fuel pump for few seconds till its obviously at pressure, pull the 'choke' and after a crank or two it fires up, perhaps on 4 cyl for 1-2 seconds, then all 6. The fast idle at 1200rpm is pretty steady on all 6 cyl. Only difference if not used for several weeks is the time on 4 cyl increases, perhaps to 4-5 secs. I guess a couple of the non-return valves on the injector lines leak back, but overall as the car runs quite well, I leave well alone and accept that for a 44 year old car I think its reasonable. How does that compare with your cars behaviour? Good luck in your investigations... James. Quote Link to post Share on other sites
JohnG Posted March 5, 2015 Author Report Share Posted March 5, 2015 James When I bought the car, starting was an issue, with just 2/3rds of the available cylinders responding on start up Having put in a lot of time, tweaking and fiddling, I have her close to acceptable Now, in brief; 1 Set the fuel pump running for about 30 seconds 2 Turn her over with approx 3/4 'choke' and a touch of throttle She will fire up. If it has been more than a few days, it will be on 5 cylinders, which very quickly becomes 6. In a minute or so, I can get rid of 90% of the choke and she will run reasonably smoothly In another 2 or 3 minutes, I can bin the choke completely, she runs slowly, but stays running Once warm, she ticks over quite nicely at about 900 rpm But . . . I still need to use the choke when pulling away, otherwise she seems to die as I give her some juice I just feel she needs a little . . . . . . . something, to ease this final issue. I don't know if Peters trick with the cable will have any effect, but, if it works, great, if not, hey ho, I can reconnect and try something else from the huge reservoir of knowledge on the forum. One thing is for sure, there is going to be no shortage of ideas! To be fair, once she has warmed up, I have very little to complain about Quote Link to post Share on other sites
AndrewP Posted March 6, 2015 Report Share Posted March 6, 2015 My experience is much the same as Jim and James (and others) Correctly set, the system should work nicely and will not need disconnecting. In fact, it should make the car driveable from the go, even on the coldest days. When you say 'tweaked' the throttle position, do you mean set with an airflow meter? If you fully close off the idle screw, does the engine all but stall? If not, you havent set the butterflies OR you have an air leak somewhere. You have all the reconditioned parts, so its probably now just down to setup and possibly chasing a leak somewhere (check the 1 way valve, check the brake servo, check the hose from the MU to the throttle body etc etc.) Hope it helps. Quote Link to post Share on other sites
JohnG Posted March 6, 2015 Author Report Share Posted March 6, 2015 Andrew Tweeked as in, I have a Crypton synchro Check, which I have used to balance the airflow, within reasonable limits. Trying to get them all the same was a chase I did not want to start. Next, I checked all the throttle linkages and reset them, by the book (Haynes in this case) Then, I adjusted (tweeked) the linkages until all the butterfies opened at the same time I then checked the butterflies at rest, with feeler gauges, and made minor adjustments so that, again within reasonable limits, each was positioned within its housing, the same as all the rest. These last 2, combined, made a significant difference Maybe things have not been done in exactly the right order, but, I have a much improved car now and that's what I was after. Now, I want to bring her up by that final notch, before I get her back out on the road. To be honest, now, I am just playing! Quote Link to post Share on other sites
Prefect Posted March 6, 2015 Report Share Posted March 6, 2015 My 74CR has had the throttle cable ditched by the PO. The car starts realy easily but two things have made life so much better first Pertronix ignition and the car starts Easy Peasey then fitted Iridium Plugs and now the engine fairly leaps out the engine bay when I turn the key. The MU was set up by Carl at RTR though which is the touch of a god. Quote Link to post Share on other sites
JohnG Posted March 6, 2015 Author Report Share Posted March 6, 2015 Yup She has electronic ignition and the change to multi electrode plugs was a vast improvement. MU and injectors done / supplied by Neil Ferguson, who also helped with the final set up on the car. I had planned to work on the car today, but, I was informed in no uncertain terms that the lawnmower was in dire need of some exercise Sunday is the next car day, assuming there are no other 'surprise' actions being planned elsewhere! Quote Link to post Share on other sites
Guest ntc Posted March 6, 2015 Report Share Posted March 6, 2015 I have heard many comments over the years regarding cars starting on 4 then 5 and 6,set up correctly they should start on 6 every time unless it is very very hot outside air temp and the fast idle cable is a waste of time. Quote Link to post Share on other sites
JohnG Posted March 7, 2015 Author Report Share Posted March 7, 2015 (edited) Neil I agree. The plan when they were built did not include allowing any cylinders to take a rest. Whilst I am quite relaxed about the whole thing, as; The 'missing pot problem' happenes only after standing for extended periods and then only for the 1st 5 - 10 seconds of running time, I would be happier if it didn't happen. I am very capable of 'squeezing' the throttle and 'easing' the choke at the same time A couple of things you can be sure of; It won't stop me driving and enjoying the car It will give me an excuse to continue to spend time tinkering I will continue to pick the combined brains of the forum. The answer is out there Edited March 7, 2015 by wjgco Quote Link to post Share on other sites
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