

Produced from - | Oct 1957 |
---|---|
Until - | Nov 1961 |
Home - | 3792 |
Export - | 112680 |
On Register - | 75 |
In Club - | 51 |
Latest - TR3A is it a UK supplied car ?
by thescrapman
< TR5/6 Exhaust for spitfire Hydrocarbon high causing misfire? Tonneau TR6 > | |
---|---|
![]() posts: 83 North Hampshire group joined on Wed 14th Apr 1999 |
posted Wed 3rd Aug 2011
My TR6 is popping/back firing under load after running for a while. Garage have measured high hydrocarbon on 1-3 cyls and suspect this is cause (2000 compared to 500 on 4-6 cyls). Compression on all cyls (engine recon some years ago but only 3k miles done) is even and good. Oil pressure great. Any clues anyone? Don't want to start a witch hunt/engine strip down if its likely to be something else. Carbs are recon set HS6 SU and appear to be OK. Also garage found a score mark on no 1 cyl, not sure if this is an issue since compression OK. Andy-------------------------------------------------------------------------------------------- 1971 TR6 - Carmine 1968 Lotus Elan +2 |
Tags - TR2 TR3 TR3A TR3B TR4 TR4A TR5 TR250 TR6 | |
![]() posts: 345 non member |
posted Thu 4th Aug 2011
reply 1 of 6
Mixture too rich especially as it is running on carbs and affecting cylinders 1 - 3. How were the garage so sure? So presumably one carb set too rich. Could also be oil perhaps a sticky piston ring from not much use but if compressions are okay that may be a blue fish. PJM (Ginger, Triumph Stag Man O/D, Strombergs) |
Tags - TR2 TR3 TR3A TR3B TR4 TR4A TR5 TR250 TR6 | |
![]() posts: 8769 Wessex (Bristol & Bath) group joined on Sat 19th Nov 2005 |
posted Thu 4th Aug 2011
reply 2 of 6
The high hydrocarbons is the RESULT of the misfire, not the cause. The hydrocarbons measured are the unburnt fuel. Do you know whatthe CO reading was at the same time? Low CO with high hydrocarbons is either an ignition misfire or lean misfire, high CO with high hydrocarbons suggests very rich. Somerset UK Vitesse Mk 1.5 Convertible EFI, Survivor of RBRR 2008, HCR & 10CR 2009, HCR 2010, 10CR2011, HCR 2012, 10CR2013, 10CR2015, HCR 2016 & HCR 2017. GT6 Mk3 Roto - project in progress Spitfire MKIV son's project now on the road as a daily driver 2.5 PI Saloon now EFI (PIe?), Engine rebuilt and running sweet. Diff howling...... Survivor of HCR 2013 & 2014 Gone to live in Swansea http://www.tengaston.plus.com |
Tags - TR2 TR3 TR3A TR3B TR4 TR4A TR5 TR250 TR6 | |
![]() posts: 83 North Hampshire group joined on Wed 14th Apr 1999 |
posted Fri 5th Aug 2011
reply 3 of 6
Thanks for ideas - Yes - HS6 SU carbs - and yes twin exhausts. I replaced float valves with gross jets (ball type) to stop flooding, since old valves kept sticking, randomly. As far as I know full supply to carbs is Ok, but will check front carb now which is fed first - unless garage got wrong exhaust/cyl numbers... -------------------------------------------------------------------------------------------- 1971 TR6 - Carmine 1968 Lotus Elan +2 |
Tags - TR2 TR3 TR3A TR3B TR4 TR4A TR5 TR250 TR6 | |
![]() posts: 674 Vice Chairman Club Torque Editor Comp Committee Member North London & Herts group joined on Mon 3rd Nov 1980 |
posted Sat 6th Aug 2011
reply 4 of 6
As Nick says the high HC reading is the result, not the cause. This, as he also says points to a mixture problem with the front carb. Whether too rich or too lean you will get high HC (I would suggest that a HC reading of 500ppm on the rear carb is too high also - you would expect around 400 at idle dropping to below 250 at 3000rpm if all is well) so the CO reading needs to be known to ascertain whether it's too rich or too lean for sure. Maude: '66 2000 (for now) in amazingly good nick with Webasto sunroof, manual now with o/d. Much electrickery, Alfa seatery, power steerery, front suspendery (ooer!) & a few other clever bits also now done. Derek: '63 (ex Derek Pollock) TR4 with Surrey top in "Triumph Racing Green" according to the original bill of sale. Probably the best, most original TR4 in the country if not the World - and that's not an idle boast. |
Tags - TR2 TR3 TR3A TR3B TR4 TR4A TR5 TR250 TR6 | |
![]() posts: 83 North Hampshire group joined on Wed 14th Apr 1999 |
posted Mon 8th Aug 2011
reply 5 of 6
Thanks - should know more later today when I get an update report from the garage. Andy-------------------------------------------------------------------------------------------- 1971 TR6 - Carmine 1968 Lotus Elan +2 |
Tags - TR2 TR3 TR3A TR3B TR4 TR4A TR5 TR250 TR6 | |
![]() posts: 83 North Hampshire group joined on Wed 14th Apr 1999 |
posted Wed 10th Aug 2011
reply 6 of 6
Well garage got hydrocarbons down to 600 by mixture and timing and tappets adjustment. Still popping when hot and under load though. They are trying new leads, plugs, have tried a different coil. When I get it back I have a gt6 dizzy to try..... Now also worried about the fact I reused the existing short inlet manifold, maybe will try a long reach one since carb float chamber is too close to steering column, and I believe the long reach one offers more power. Plugs were BP6E (?) should I try ES? Andy-------------------------------------------------------------------------------------------- 1971 TR6 - Carmine 1968 Lotus Elan +2 |
Tags - TR2 TR3 TR3A TR3B TR4 TR4A TR5 TR250 TR6 | |
Club Triumph Ltd. Registered in England No. 4961210 Registered Office: Suite A,10th Floor, Maple House, High Street, Potters Bar, Herts, EN6 5BS. VAT registration number 340 4536 26. Club Triumph is run entirely by its members for its members and does not have paid employees.
Website Terms and Conditions | Terms and Conditions of Sale | Privacy |Club Rules