TR6 - lack of response

[Trigbush]

I took the 6 out this morning. Gorgeous sunny morning - 18 degrees. But I had a discernible problem.

 

Car started first time, very nicely. I let the car warm up before taking her out on the road. But at every next red light, although the car idled nicely, the minute I depressed the accelerator, the engine cut out. Once started (and high revving to get it going) there was a very discernible lag after changing gear and depressing the accelerator. Sometimes this led to the engine misfiring. Not always.

 

I headed out onto the ring road south and the car ran very smoothly up at 100km/h down to Waterloo in overdrive. But turning off, the minute I hit the local roads, the issue returned. I then pulled off to lift the lid. All injectors were firing nicely, the car even idled nicely, it was just that moment when first depressing the accelerator, there was a discernible lag in response (and in first this caused it to stall). It feels like a bubble in the system that then gets pushed through and then ends in a misfire.

 

After thirty minutes the effects were less noticeable and the changes were much smoother.

 

I got back safely. Checked the brown book.

 

- it is not erratic iding but more "lack of response"

 

- engine mis-firing is not the principal issue

 

I think I can exclude incorrect injection order, incorrect idling speed, excess fuel level adjustment, continuous injection, or fuel leaks.

 

Could this be incorrect line pressure?

 

(Also I have the recurring fuel pump "whine" after about thirty or forty minutes). I wonder whether it may also be a faulty fuel pump filter?)

 

I did do a search on the forum but did not immediately find anything.

 

Grateful for any comments.

 

Have a great weekend all

 

Cheers

 

Gavin

 

p.s. I also filled up with new fuel last weekend but had less of an issue last Sunday.

Edited March 9, 2014 by Trigbush

[Guest ntc]

Most of the time it will be electrical , check points etc

[Peter Cobbold]

Could be spark timing. Has the points gap cosed up?

Peter

 

 

edit: as Neil says

Edited March 9, 2014 by Peter Cobbold

[Trigbush]

Thanks. That's helpful. I will check.

[graeme]

Gavin,

 

The symptoms you describe are typical of an air leak on the induction side. Check all pipes and connections on the manifolds.

 

Cheers

 

Graeme

[fox889]

Nobody has mentioned a partially blocked fuel filter?

[Trigbush]

Thanks Guys.

[Sparkplug]

Could it be that the oil in the dashpot on the carbs too thick, not letting the pistons rise?

[peejay4A]

Gavin's car is on PI so no carbs.

 

I had similar problems with my 6 which turned out to be the Lumenition control box overheating.

[Sparkplug]

Sorry, I didn't see "injector" in the post until now.

[carld]

My guess would be crud in the fuel, do you have a pre filter before the pump?

[PJM]

Theres always a clue in the question

 

 

I headed out onto the ring road south and the car ran very smoothly up at 100km/h down to Waterloo in overdrive

Could just be us British taking a good look around before commiting and making sure we dont get caught napping

Edited March 11, 2014 by PJM

[NWYzoom]

TR6 PI Bosch pump and Lumination

 

I had the same problem today. I took the car out for a first run after the rains and it started ok. 5 min down the road it would only run smoothly at 2000 rpm + then it would die at idle. It restarted a couple of time after 5 min rests, but then would not start at all. Towed it home. Any bright ideas?

[peejay4A]

Refit the contact breaker points and try it.

Edited March 17, 2014 by peejay4A

[Trigbush]

So a (partial) update on the 6. It's been in the shop since April (don't ask - welcome to Belgium). I got an update yesterday which to be honest I don't fully understand. I was told there was slack in the timing chain and at the same time the camshaft would not turn over. I think the implication being that the lack in response is as a result of play in the timing chain and resistance in the camshaft. The chap has removed the distribution and he is checking further.

 

I have called the Red Baron Garage and asked them to call this chap to make sure I have fully understood this (my technical French is limited). I also want a sanity check on this...

Edited June 11, 2014 by Trigbush

[peejay4A]

Gavin,

That sounds a bit of an iffy diagnosis to me and I'd ask them to expand on it. If the camshaft won't turn the engine won't run at all.

[Peter Cobbold]

Gavin,

+1 with peejay - very iffy indeed. Cams dont stick. Something happened between one run and the next, timing chains go off over thousands of miles. Get them to refit the disy and get it home. We can sort it out from here.

Its either spark timing or mixture. To get started: check points gap, the fuel filter ( unless its the original type), and give the PRV a good thumping.

Peter

Edited June 11, 2014 by Peter Cobbold

[Trigbush]

Thanks Guys. That's what I suspected. I can understand the need to replace the timing chain but the camshaft?

[Guest ntc]

They are talking bull!!! chap,if the chain is shot so will be the sprockets ,the tensioner will be also and will have worn a groove in the front plate easy to weld up by the way. Ask them to spin it over and watch the rotor arm.

Edited June 11, 2014 by ntc

[Trigbush]

Thanks Neil.

 

I spoke to Red Baron who had called the Lemaco chap. They also think the explanation is iffy ("the Crank is not driving the valve train"). They think there is likely a metering unit issue. I suspect that Lemaco have less experience with TRs and even less with PI cars (however nice this chap is I don't think he knows what he is doing on this motor and he is under water with other cars being a classic generalist - MGs, Jaguars, Healeys, etc). I called Lemaco and told them to down tools. I have agreed to see their sheet for work done to date and we will agree a price (not a big amount). I will then trailer the 6 to Red Baron end of next week to sort this out.

 

I just wish this had been done in April. Grrr!

[elclem1]

Would it be a sticking choke? Wouldn't,t be the first time..........Gavin I think your Belgian garage is having a laugh, if you ever need tech speak my French is quite good on the technical side of things especially sixes. Good luck andy

[Guest ntc]

My money would be on damaged drive dog on the cam ? seen to often by me in the past repro cams or made of cheese.

[Peter Cobbold]

"the Crank is not driving the valve train"

???? That would result in pistons clouting valves - absolute mayhem. Its not that.

Why do thay think that?- is the disy not turning when the crank is turned? - easy to check when its home.- see Neil above.

 

Or is it the plastic drive dog that turns the MU rotor. That could fail and leave the MU turning somewhat, but not as rapidly as needed (I think) - leaving a very lean mixture hence the bad hesitation, and misfiring.

Easy to check that and replace, at home.

 

Peter

Edited June 11, 2014 by Peter Cobbold

[Trigbush]

Thanks guys. I agree. Have lost any confidence in this guy. I will keep you updated. Difficult to progress this whilst I am stuck in the office and the car is stuck in this guy's garage. It cannot be moved now without a trailer...

[Trigbush]

I am so bloody furious right now.

 

Just had a call from my man Rolf at Red Baron - they have had a moment to look at the car (they were prepping the racing cars last week http://www.redbaronclassicracing.com/).

 

Rolf has just taken a look at the car this morning. He put it back together again. It appears that after closer inspection there was a very small tear in the metering unit vacuum hose and the metering unit setting had been re-set to idle... With a cheap as chips hose replacement and a couple of hours work (mainly putting the car back together again) and re-setting the MU - he has got it running very smoothly. The tear would have been difficult to spot on inspection but appears to have caused the MU to suck from the outside... He said he cannot understand what Lemaco were doing as if they had gone about inspecting the car properly they would have eventually spotted this fault. I can only think that the MU setting came about as they were playing with it.

We are now just over three months after I first took it to them. I am never going back to Lemaco. That's for sure (and I am certainly not going to pay them for their efforts). We live and learn folks, we live and learn.