TR6 that struggles up hills

[88V8]

...especially with webbers being a swine for going off!

Especially if left outdoors for a week without being cleaned since the last barbie

[Guest ntc]

especially with webbers being a swine for going off!

 

Tosh fit/jet and forget, they are far more reliable than a mechanical injection system

[CONCRETE24]

Hi Nick,

FYI My old Spitfire behaved exactly as you describe when the Head Gasket had started to fail, (luckily the TR6 has not had such a problem)! It gradually got worse (and I mean over months) until it was not just hills it struggled with! It was not a drastic failure, (the oil and water never got intimate) which was why it was difficult to diagnose. More support for a compression test?! Good luck.

Michael.

[Bald Rick]

especially with webbers being a swine for going off!

 

Dave

 

I worked with Alfa twin cams and a few examples of Italian "exotica" for a couple of years. Some of them fitted with 6 twin choke webers. I don't recall that they were prone to going off tune.

 

In my experience, once set up properley, Webers are pretty stable unless fitted with poor throttle linkage, or onto **** manifolds, or run continuously without the correct air filters.

 

Nick

 

Just had a thought which I don't think anyone has mentioned, condensers can break down under load i.e. when going up hill or accelerating hard. They can perform this feat intermitantly as well! Might be worth a look, unless you,ve got electronic ignition!

 

Tony

Edited August 26, 2009 by Bald Rick

[TIMS]

Nick

 

You have had the car for 10 years, when was the head converted to unleaded? Do the compression test!.

 

Regards

 

Tim

[PILKIE]

Having not had a lot of practical experience with webbers,I am only going by what I have heard others owners of various marques say about them!

Like any fuel system,be it pi,su,stromb,zenith,etc, and with all the **** in u/l fuel,and some additives used these days,if it isnt used on a regular basis the mechanical workings can tend to get stiff,rubbers not getting enough use and stiffening up,non compatible rubber for u/l fitted degrading.

 

[Q Tony]

[in my experience, once set up properley, Webers are pretty stable unless fitted with poor throttle linkage, or onto **** manifolds, or run continuously without the correct air filters.]

 

This could well be the case,we just dont know!

 

Somewone out there will be able to listen to,drive the car and know exactly what the fault is without going through the diagnostic elimination process,trouble is finding that person!!

Most of us will have to do it ourselves and start at the beginning and work our way from A-Z till we find the problem.

 

Some owners have no time and deep pockets and just chuck it at a dealer and say fix it!

Edited August 26, 2009 by PILKIE

[Guest ntc]

Well my money is on restricted fuel supply or the lumenition

[Nick Rowe]

Hi All,

I will try to answer all the points recently raised:

 

Neil: The luminition is 10 years old, so maybe worth looking at. And I am in possesion of a compression tester although I can't do anything to the car until the weekend.

 

Andy: I'll check the inline fuel filters, you never know !!

 

Michael: Your description sounds familiar - more reason for the compression test

 

Tim: The head has not been converted. I run with unleaded and an additive

 

Pilkie: I have K&N filters just been washed and re-oiled, throttle linkage seems fine and Webers are on Triumph Tune manifold.

 

I will give an update over the weekend and thanks for all your comments

[Eyetee]

What was the engine temp like when the poor happened?

Car was running well till it got hot suggests its not the head gasget.

possible the coil?

Or if temp was fine just an intermitant fault, fuel blockage, tank rotten...

[peejay4A]

I had twin 40DCOEs on a Ford 1600 crossflow motor once. They were forever icing up, especially if there was any humidity around. That caused the very symptoms you are experiencing but the Ford didn't have the exhaust manifold to keep the carbs warm. Just a thought.

[B Fitzpatrick]

Hi All,

 

My car was converted from PI to triple Weber 40's over 10 years ago. They were tuned about 6 months ago (as mentioned in an earlier topic), so I am assuming they are OK. The car is fitted with Luminition and I have splashed out on 6 new NKG plugs, timing checked OK ...

Acceleration has never been electric, it makes all the right noise without all the right 'G', but now when I go up hills the car really struggles.

Coming up Birdlip from the International, for example was a nightmare, with everything passing me.

The car will go along on the flat (and down hills!) quite OK.

I can start going up a hill OK, but the power slowly dies. If it was a 2 stroke I could describe the sound as if it was 4 stroking.

I have looked through the forums/fora and there are a couple of possible pointers eg: coil which I will check when I get home.

When I took the old plugs out they looked reasonable, they weren't wet and they weren't light grey so I assume fuel is getting through OK and the mixture is about right.

As I say the problem really only surfaces when the engine is being stressed, if when struggling up hill I dip the clutch and give it a rev, it sounds OK.

All thoughts welcome and many thanks in advance!!

 

Nick

 

25/08/09 Update

After all your suggestions, many thanks, I took my 6 out for a spin a short while ago to try to answer some of the questions you had asked. The only thing I have changed recently is the thermostat. Because we had a trip to Eire back in March, I anticipated some cool weather so I uprated the thermostat to 88⁰C, and I haven't changed that back.

As I said I took the car out for a spin tonight and it went fine. There is a good long hill about 10 miles from us and the car went up that without a problem. I tried the hill again and it was still OK. I came back and thought I'd give it a try along a dual carriageway, and as soon as I put my foot down it refused to go above 3000 revs, it was like it was 'four stroking' in 2 stroke parlance or it had hit a rev limiter. If I dropped down to 2500 revs it wouldn't rev back up to 3000. It wouldn't tick over at traffic lights so I had to keep blipping the accelerator pedal to stop it from stalling. The Kenlowe was going like the clappers although the temperature guage was only just high of centre.

So maybe it is just getting too hot?

I will change the thermostat back to the 82⁰C one and go through the same tests.

 

Hi Nick

What you describe I experienced recently i.e car would start up ok but 'die' under load, sorted eventually by getting a new ignition coil, so if you can borrow a functioning coil try this first - might be the solution.

 

regards

[EliTR6]

John (Eyetee) had a point. I had similar problems arising from rust inside the fuel tank. Blocked petrol flow on and off for a few months before finally clogging up the whole system. Had a new (2nd hand) tank put in, problem solved!

[Nick Rowe]

Hi All,

Many thanks again to all who have replied.

I have a spare coil and will try that, also the fuel tank may well be rusty which may be the problem.

Not so sure about the Webers icing up - still anything is on the table!!

 

Just to respond to a few previous points:

Compression testing: I brought the car up to temperature (without any issues) and checked each cylinder:

#1=200psi, #2=210psi, #3=210psi, #4=200psi, #5=210psi, #6=220psi

I don't know what they should be but they all seem to be within a reasonable tolerance. I am pretty sure nothing special has been done to the actual engine so it is as it came out of the factory.

I checked the sparks which all looked strong and the voltage on the coil indicated 12.76 with the coil -ve terminal open circuit, down to 11.86 with the coil -ve terminal connected to chassis. Coil resistance is 3.2 ohms.

 

I really need to get to a stage where the car develops the fault then stop and immediately run through the tests again.

 

Regarding the head gasket, there is a line of oil along the length of the head gasket, so I think that is worth changing anyway. I don't have any water/oil mix though.

Thanks again and I'll keep you all up to date !!

Nick

BTW there was a small glimpse of SUO600H in the photo shown in the latest TRAction under the Brunel group. It may help identify my problem

[Guest ntc]

Hi All,

Many thanks again to all who have replied.

I have a spare coil and will try that, also the fuel tank may well be rusty which may be the problem.

Not so sure about the Webers icing up - still anything is on the table!!

 

Just to respond to a few previous points:

Compression testing: I brought the car up to temperature (without any issues) and checked each cylinder:

#1=200psi, #2=210psi, #3=210psi, #4=200psi, #5=210psi, #6=220psi

I don't know what they should be but they all seem to be within a reasonable tolerance. I am pretty sure nothing special has been done to the actual engine so it is as it came out of the factory.

I checked the sparks which all looked strong and the voltage on the coil indicated 12.76 with the coil -ve terminal open circuit, down to 11.86 with the coil -ve terminal connected to chassis. Coil resistance is 3.2 ohms.

 

I really need to get to a stage where the car develops the fault then stop and immediately run through the tests again.

 

Regarding the head gasket, there is a line of oil along the length of the head gasket, so I think that is worth changing anyway. I don't have any water/oil mix though.

Thanks again and I'll keep you all up to date !!

Nick

BTW there was a small glimpse of SUO600H in the photo shown in the latest TRAction under the Brunel group. It may help identify my problem

 

Then no need to remove the head let's see what the guru's think

[TR NIALL]

Then no need to remove the head let's see what the guru's think

 

Neil,think you frightened them all away .

[Andy Moltu]

compressions are fine & within 10% of each other so unlikely to be a cylinder/piston/valve problem.

[Guest ntc]

Neil,think you frightened them all away .

 

 

Who Me

[Eyetee]

Excellent compression, head gasget good.

 

Difficult to test the coil without correct equipment (very high resistance)

Fuel filter?

What sort of fuel pump are you using?

[phil.simo]

Hi Nick,

 

Something else to through into the pot, My pals 2500S saloon had similar symptoms and it turned out that the back two cylinders were silted up in the waterways. even though the temp gauge read normal, the back two cyls where mad hot when he was giving it some beans which caused the rings to 'nip up' and it wouldn't rev up or tick over until it cooled down!

A quick way to rule this out is to remove the block drain plug or open the block drain tap if one is fitted.

 

Phil.

[Guest ntc]

Excellent compression, head gasget good.

 

Difficult to test the coil without correct equipment (very high resistance)

Fuel filter?

What sort of fuel pump are you using?

Indeed I wish it was here I would make the thing sing it should pull like a steam train with that compression, there must be someone down there that can help? and Phil that is often ignored

Edited August 30, 2009 by ntc

[TR NIALL]

Has the electronic ignition been ruled out, if no could be worth your while disconnecting it and go back to standard set up,test drive see if any change, if not go back to electronic ignition and try elsewhere, as in fuel starvation.

Edited August 30, 2009 by TR NIALL

[peejay4A]

Has the electronic ignition been ruled out, if no could be worth your while disconnecting it and go back to standard set up,test drive see if any change, if not go back to electronic ignition and try elsewhere, as in fuel starvation.

 

I'll second that. I forgot to mention in my post about icing that I've had a Lumenition system fail after 5 years or so. It only failed when the electronics box got hot, with symptoms akin to those described - would not idle but would rev, just, if you dipped the clutch. Let it cool down and all was well again. Eventually diagnosed by letting the car idle in the garage until it failed, then plonking a bag of ice on the electronics box which restored ignition after a few minutes. Repeated the whole process a couple of times to prove it. I went back to points until I fitted an Aldon unit a few years back which has been trouble free.

[88V8]

Don't know about the gurus, but I've been at rallies today/yesterday, no Neil not proper rallies just the sort where you sit in a field .

Agree no point in taking the head off. That line of oil on the spark plugs side of the engine, they often leak there and a new gasket is not guaranteed to cure it, not worth bothering about.

 

Still puzzles me that you originally described the noise as eight-stroking (I think that's what you mean, you said like a 4-stroking two stroke, well in a 4-stroke that's called eight-stroking.) Anyway, that's usually caused by a rich mixture, which doesn't make sense.

 

If swapping the Lumenition doesn't fix it - never heard that one before - well, you're not far from Pilkie, are you? He used to be a mobile mechanic and knows his way around the 6, be worth taking up his offer to have a look at it. These things can be hard to diagnose at a distance, even for the gurus whoever and wherever they are.

 

Ivor

[Nick Rowe]

Hi All,

 

Thanks again for all your comments. It was good to hear that the compression is as expected, and that the thermostat is unlikely to lead to the cause. A couple of things to knock off the list ...

 

The current favourite is the Lumenition. I must say I didn't expect any issues after fitting electronic ignition (although it was 10 years ago), but who knows and the description given by HPA510K, thanks Pete, is very similar to my problem. I can borrow a recommended Ignitor system to try out, so that will be my next course of action.

 

I'll keep in touch, but there may be a delay of a week or so as other things have taken precedence at the moment.

 

Many thanks again, and at the next International, I'll buy you all a pint - and a straw each to go with it !!!

[Nick Rowe]

My apologies to all who have been kind enough to reply to my woes. I took a holiday of a lifetime back in September - November and as I only have a single garage and have to work outside, I have only recently got around to investigating the problem further.

I believe the problem has been resolved.

I have discussed this with various knowledgeable people and it was suggested if the problem related to fuel then pull out the choke when next the problem arose - if there was no difference then ignition should be suspected.

I took the TR out on a number of test runs and it behaved perfectly. But eventually it failed again with the '8 stroking' problem. I pulled out the choke and it made no difference. So ignition was the suspect.

I borrowed some contacts etc from Bob Crocker to eliminate the electronic system and go back to basics. I decided to do this at a friends workshop which was about 12 miles away. I set off but within 3 miles I was in trouble. This time it occured on the flat - not up a hill. I managed to stagger on to find a safe place to pull over and stop. I noticed the glass inline petrol filter was nearly empty. Typically ever since I have had the car this has at best been half full (or half empty). I tried manually pumping the mechanical (remember I use Webers) fuel pump but the glass inline did not fill up. Anyway after several further stops I eventually got to the workshop.

There I took the fuel pump off and discovered a slight tear in the diaphragm. The bowl of the pump was dirty as well which indicated fuel was passing through the diaphragm - so the problem was solved. Replace the diaphragm, took the car on a 10 mile test trip and it went better than it ever has before. I guess for the first time, sufficient fuel was suppled when the Webers requested it!!

So I drove home and guess what, it stopped completely .... the inline filter was empty, I made sure there WAS some fuel in the tank but manual pumpimg had no effect. I had to get Eric to tow be back to his workshop.

We took the inline filter out for investigation. There is a thumb screw which had worked loose and appeared to be blocking the holes in the internal fuel pipe. Once this was firmly screwed back to retain the filter, the fuel pump did what it supposed to do again.

I had an uneventful journey home and although I haven't taken the car any huge distances since then, I feel confident the issue/s have been resolved.

So the whole problem related to lack of fuel due to a torn diaphragm AND a loose thumb screw.

Many, many thanks to all who have offered suggestions and assistance. It's always good to know there are people out there who are prepared to assist when needed.

I hope this is the end of this particular issue and I now feel confident that the trip to Le Mans Classic will be attainable.

Again, many thanks to everyone mentioned in this topic.

Nick