Eddie Trickett Posted March 20, 2022 Report Share Posted March 20, 2022 Have completed the refurb of the H4 carbs and fitted them but the car won't start. I haven't touched the ignition at all. Timing checked OK,spark at each plug, firing order correct, plenty of petrol getting to carbs( I had trouble with leaks at the banjo bolts) but car won't start. Pistons move freely in the carbs,have swopped the plugs,still won't start , not even firing. Have left the battery on charge but stumped by this. Any suggestions? Thanks Eddie Quote Link to post Share on other sites
roy53 Posted March 20, 2022 Report Share Posted March 20, 2022 spray some fuel direct into both carbs that should enduce firing . Then it will be fuel supply to carbs Quote Link to post Share on other sites
TR4TUNE Posted March 20, 2022 Report Share Posted March 20, 2022 Assuming H4s are much the same as H6s.... I had trouble starting the car after sitting for a while last winter.It would turn over but sounded rough as a badgers...the cause was the choke skicking open on one carb....the jet is lowered when you pull the choke which allows more juice to flow.Mine stuck open due to dried out cork gaskets sending too much juice when not required, a new SU kit sorted the problem.You can check with a mirror if the jets return once the choke is released or perhaps easier to see if filters removed.Take a plug out and see if it is wet. Also if you fit new needles they are not meant to be seated in the piston before tightening up the screw...apologies if too basic. Quote Link to post Share on other sites
Waldi Posted March 20, 2022 Report Share Posted March 20, 2022 Is there fuel in the float bowls? Quote Link to post Share on other sites
Lebro Posted March 20, 2022 Report Share Posted March 20, 2022 Are the plugs wet Bob Quote Link to post Share on other sites
Ian Vincent Posted March 20, 2022 Report Share Posted March 20, 2022 1 hour ago, TR4TUNE said: Also if you fit new needles they are not meant to be seated in the piston before tightening up the screw...apologies if too basic. What does this mean? Rgds Ian Quote Link to post Share on other sites
BlueTR3A-5EKT Posted March 20, 2022 Report Share Posted March 20, 2022 (edited) Eddie, have you read this article about fitting the needle. http://sucarb.co.uk/technical-h-type-carburetter-reassembly Lots here from MGA Guru on H type carbs. https://mgaguru.com/mgtech/carbs/carb.htm Edited March 20, 2022 by BlueTR3A-5EKT Quote Link to post Share on other sites
Eddie Trickett Posted March 20, 2022 Author Report Share Posted March 20, 2022 Thanks for the replies Definitely petrol in bowls, I had a few leaks and was surprised how tight everything needed to be to stop leaks, especially the banjo bolts . Thought I had centred jets OK but now one piston drops with a clunk and the other slightly quieter. However plugs don't seem to be very wet after cranking many times. I will try some easy start tomorrow to see if I can get it going. Thanks again Eddie Quote Link to post Share on other sites
RobH Posted March 20, 2022 Report Share Posted March 20, 2022 Have you pulled the choke out all the way? It can be very stiff on the sidescreen cars if that is what you have, so you think it's fully open but actually it's only half way. That makes all the difference for starting. Quote Link to post Share on other sites
TR4TUNE Posted March 20, 2022 Report Share Posted March 20, 2022 Ian Vincent, See BlueTR3as reference to the SU bible. It is too easy to insert the needle too far into the piston and nip it up which results in running rich as the needle then sits too high in the jet orifice. I found that if you hold the needle between thimb and forefinger, at the shoulder of the needle, you can then lower the piston on to it and tighten the wee grub screw to hold it in place.......then all you have to do is set the jet height correctly (SU sell small spanners to adjust the jet height which makes life easier). John S Quote Link to post Share on other sites
Eddie Trickett Posted March 21, 2022 Author Report Share Posted March 21, 2022 Started today with Easy Start. Doesn't sound too bad considering I have not adjusted the carbs yet. Still a mystery why It wasn't even trying to start before using Easy Start. It now starts better than ever before. Thanks everyone for the advice. Eddie Quote Link to post Share on other sites
Keith Wigglesworth Posted March 21, 2022 Report Share Posted March 21, 2022 How old was your petrol when you tried to start the car? I put new fuel in the filter bowl after allowing some fuel to run though the system. It sometimes still needs some QuickStart to help get things going. The problem gets worse with the age of the fuel. The fuel when old looks yellower and less clear. May be a contributing factor. I have changed all sorts of components to try to get the car to start better after a lay off and it was the petrol all along. hope this helps. Keith Quote Link to post Share on other sites
Eddie Trickett Posted March 22, 2022 Author Report Share Posted March 22, 2022 Keith, It might have been the petrol. I've read that the ethanol attracts water and maybe I had some at the bottom of the tank. The car had become more difficult to start over the winter and I didn't take it for a run so the petrol at the bottom of the tank wasn't getting used. Just tried it today and it started first time and I haven’t adjusted anything from when it wouldn't start so hopefully everything is OK now. Eddie Quote Link to post Share on other sites
trevor Posted March 24, 2022 Report Share Posted March 24, 2022 I have just had the same problem and filling the filter bowl with V-power started first time , so this will be my routine after a winter lay-up. Quote Link to post Share on other sites
Eddie Trickett Posted March 24, 2022 Author Report Share Posted March 24, 2022 Car starts fine now but I am having a problem with petrol leaking at the carbs. I have tightened the banjo bolts as tight as I can and the float chamber bolts underneath seem to be OK now but needed excessive tightening. However I have petrol leaking past the jets. I have used the 2 viton o rings in place of each Cork seal to make the seals ethanol proof but they seem to be leaking and these can't be tightened up. Anyone else have this problem with H4 carbs. Thanks Eddie Quote Link to post Share on other sites
RogerH Posted March 24, 2022 Report Share Posted March 24, 2022 Modern plugs do not like getting or sitting with damp plugs. I;ve gone back to Champion L87 plugs as the NKG's didn't last any time at all. Roger Quote Link to post Share on other sites
Motorsport Mickey Posted March 24, 2022 Report Share Posted March 24, 2022 1 hour ago, RogerH said: Modern plugs do not like getting or sitting with damp plugs. I;ve gone back to Champion L87 plugs as the NKG's didn't last any time at all. Roger Going back to the time when to own a TR4 meant you were only 25 years away from what was a new car, buying NKG spark plugs (the dyslexics friend lol) was reckoned to be the way to get TRs to run without fowling when they got hot...and then cold. At that time I worked for a Leyland truck dealership and enquiries to mechanics at the local Mann Egerton dealership workshops situated at Triumph road (nicely named), came up with the opinion that there was NO difference between the performance qualities of Champion or the more correctly named NGK plugs. HOWEVER there was an opinion that the qualitive difference was down to... quality testing. ie the NGKs were MUCH more rigorously tested. Meaning many more failures for NGK within their factory gates as against the Champions expiring in service on customer cars on the A38 somewhere between Lichfield and Burton (for owners below Watford Gap that's ...in the North). Whether now NGK has rescinded their aggressive testing regime (alleged) and now like Champion their testing is carried out by their customers is unconfirmed. Mick Richards Quote Link to post Share on other sites
RogerH Posted March 24, 2022 Report Share Posted March 24, 2022 Hi Mick, from what I have heard; because modern car engines are seriously lean burn there is no need for excessive glazing on the ceramic body. So, our very wet engines get the plugs damp and that soaks into the ceramic - not good. About 4 years ago (in Ireland) I was having horrid trouble with the NGK's. They were lasting about 500 miles or so. Back home I changed to the Champ 87 and now getting about 5000 miles. It could be rhubarb but...................... Roger Quote Link to post Share on other sites
TR4TUNE Posted March 24, 2022 Report Share Posted March 24, 2022 Had same problem on one carb. Sorted by replacing dried out cork seals with new cork seals soaked in oil for a day or two. My undersranding was that folk used the teflon rings to get a better longer lasting seal, not because of ethanol.....Wine bottles are sealed with cork and some of them have over 10% ethanol, hic. Check your needles are inserted correctly. Check your jets are set to the correct height below the bridge, have a look with the filters off. Check that when you release the choke that the jets return to the correct height....again look with filters off. The SU web site has excellent diagrams and info for assembling the carbs. Good luck, you will sort it eventually. John Quote Link to post Share on other sites
stuart Posted March 25, 2022 Report Share Posted March 25, 2022 Most of the NGK problems are down to fakes that are widely circulating within the aftermarket sales industry Im afraid. New NGK have always had a problem with fouling if run too rich, I usually use an old set for initial startups until tuning is corrected then fit the hew ones, thats been the case for probably 30 yrs now. Stuart. Quote Link to post Share on other sites
Eddie Trickett Posted April 5, 2022 Author Report Share Posted April 5, 2022 Swopped viton seals for cork and replaced the springs. Springs noticeably stronger than the old ones. No leaks now. Eddie Quote Link to post Share on other sites
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