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Triumph TR6 - Carb Settings and Vacuum
|OK, first thanks for everyone putting up with my Q's. On to the next...I've got the carbs set-up to idle, sync and fast idle + timing set to where the car starts with the flick of the key and idles along pretty smooth at 900. All the aforementioned set by the book with aircleaners removed and vacuum disconected and plugged THEN I put the aircleaner back on and hooked up the lines from the valve cover to the carbs/charcoal can and VIOLA it will barely run...so I disconnect the lines to the valve cover and plug the ports and she fires up and idles fine. The PO had a nice piece of heater hose run from the valve cover to the road (nice, I know) and had these ports plugged. Any suggestions? I'd like the vent from the engine to work properly.|
Sounds like you have a large vaccuum leak in the vaccuum lines somewhere. Check them for leaks. Do you have the restrictor in the line? This controls the vacuum and pressure in the system. It is after the carbs/ rocker cover vent and before the carbon cannister
See page 89 of the TRF blue book.
You can try to do the final adjustments (timing/carb idle) with all vacuum hoses connected and see if that gets it right.
Mine is a 69 without all the carbon junk etc and I am happy with that.
|Yes, there is a White restrictor where that line enters the canister. I'm going to dig deeper and make sure the canister system is "tight" I'm sure at this point it's been compromised...many a PO mistake over the years as I'm discovering. It's what makes the hobby fun and a challenge.|
|How did you adjust your carb needles? You may be running rich. Rich fuel mixtures blacken your sparkplugs. You'll initially have an easy engine start because of a lot of fuel but, eventually, your sparkplugs blacken and the engine becomes difficult to start. Pull your sparkplugs off and see what color they are. If light grey, you've got to much air and not enough fuel. If Black, you've got to much fuel. If grey, perfect!! Adjust your needle approx 1/2 turns each time. Remember: "Turn right makes it Rich, turn left makes it lean."|
|oops I forgot, did you check your distributor adustment?|
|I adjusted the needles by lifting the slides when at idle and seeing how the engine responded (according to the book in other words) Yes, the distributor was checked.|
|The book is a good basis for academic adjustments. The reality is adjusting carbs is an art. That being said, lets make you an artist. Lifting the pistons is a good idea to check for fuel/air mixture but cannot be relied upon exclusively. Pull each of your sparkplugs out and see what color they are. then repost your results. Try to post your results as: Light grey, grey, black or as accurate as you can.|
Do you have the original camshaft profile? Or did you go for a hotter cam? This will dictate your distributor adjustment. I personally have a Goodparts gp2 cam which is a little hotter than the original. Because I've added a higher ratio rocker arm setup, I have to really advance the distributor. If I don't, I'll have a similar problem that you do. As soon as I install all the vacuums and air filters, It dies.
|Benji...thanks for your help/input...many here can gain insight. No offense but if you read some of my posts you'll see I've restored/rebuilt everything from Triumph Bonneville's to Royal Enfields to MG's..amals, mikunis, SU's. I appreciate your enthusiasm but I'm well versed in the ability to set/balance/tune carbs as well as adjust proper air/fuel, rich/lean. My original post on this thread isn't in regards to carb set-up but an alternate PCV setup then the stock valve cover to charcoal can. I've already deduced my problem is a PO has allowed the can to "free vent" which in turn has no restriction to the PCV/Fuel vapor recovery. Problem resolved.|
|Sorry JT, I haven't been on this thread for a couple years now so I didn't know you've addressed the carbs. So, are you still looking for an alternative pcv set up? Or is you problem resolved?|
If so, was the vent on the valve cover were your problem came from?
I free vent my valve cover every winter because of the moisture we get up here in the Northwest and have had no problems. Spring time is when I rehook it up to my oil separator rather than the carbon cannister.
|Benji...no problem. Many here will benefit from your experience with the rich/lean/plug color...FYI, I pulled the plugs and the front carb plugs were a nice medium to light grey while the back were med to dark grey to just getting dark/rich so I leaned out the back one a 1/2 turn. The charcoal can is a shambled mess of PO interference! I just got the new MOSS catalog which shows each years emissions can set-up broken down by year which makes replacing everything in the right manner most helpful. The Stromberg's are a notorious pain in the neck but I feel I'm getting them nailed down pretty good at this point.|
|Just ensured all restrictors are in place and ALL lines hooked up according to stock configuration on the charcoal can, fuel tank, carbs....it will only idle with the vent tubes plugged from the valve cover to the carbs. Really frustrating in that it's set up properly with all tubes/lines replaced and everything as BL meant it to be and still no luck unless I plug off the vent tubes on the carbs...hhhmmm|
I read your first line of your last post.
I presume you included in this count the restrictors in the 2 hoses that go to the 2 carbs? It kinda sounds like one is missing. OR, is one of the lines pluged?
There are some cars out there with no Carbon canister at all (disconnected). I do appreciate you wanting to at least vent the valve cover back to the carbs.
PS Hi Benji.
|Benji, I had all the restritors in place (they actually were left by the PO on the car) The car sat for over 9 years so it's inevitable the Stromberg's will need a good going through...I went ahead and ordered a set of rebuilt HS6 SU's for it just to be rid of the Stromberg headaches before they start. I'll take my time and rebuild the Stromberg's and either keep them around for originality or sell them off in the future.|
|I can appreciate your frustration JT|
Have you tried to do the adjustments with all the lines hooked up properly (and not following the instruction manual and not plugging off the vent tubes)? All that matters in the end is if you can get it idling well and accelerating and moving with some power.
You know- I could use a nice trip to Florida. If you can scrape up the airfare, I will come down and help you. No guarantees though that I can get it going right but at least you will have someone to commiserate with. I will even bring the beer. I do have a colourtune kit as well that may help. ;-)
In all seriousness , though, it still sounds like there is too large an air flow through the carb vent lines and you are not getting enough venturi/vacuum effect in the carbs to supply gas for idling. You could try partially pinching the lines from the carbs to the cannister as those lines are meant for vapour (Canadian Spelling) recovery when the car is off and do not need to be unrestricted.
|I tell ya', I like the stroms. They may be a little tempermental but, they sure are nice when you sort them out. Here's a great website if you want to tackle them before you spend money on the hs's|
Look at the section:
TR250 and TR6 Carburetors:
Part I - Disassembly & Theory
Part II – The Overhaul
Part III – Reinstall, Tune and TroubleshootingHey Rick, I think it's been about 5 years since you last stopped by. I wonder if Don's Tr6 is running by now!!
|Thanks Benji, I've been through those sites before. The SU's should be here today or tommorrow. I got a heck of a deal on the SU's and couldn't justify the cost of the rebuild kits and sorting of the Stromberg's vs the cost and reliability/ease of the SU's for the price I'm getting them at + I get to keep the Strombergs for originality/re-sale if need be.|
This thread was discussed between 12/03/2010 and 23/03/2010
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