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Triumph TR6 - '71 PI Engine not runnig very well on low revs

Hi :)

This is my first post here, and I'm quite new to the TR6 as well, so this might be a rookie question for you folks out there. I'm not even going to pretend to now a whole lot about mechanics, but I have spend enough hours working on the TR6 this last half a year for my wife to give the car a suitable name:)

I bought a US '73 Triumph last fall, with a '71 PI engine fitted. This runs quite well idle, as well as on high revs, but between 1000 and 2500, it has big problems under acceleration. Particularly if cold. It loose power and it runs really uneven, jumping and coughing. It actually seems like it pushes too much petrol. I get a similar effect when I pull the choke when driving.

I've checked the injectors, they seem to be fine, I've changed the coil, checked the distributor, changed the lead and spark plugs. No help. I haven't changed the injector pipes, though. I'm thinking that if it gets too much fuel, it might be the metering unit. Also I've been advised not to mess with the metering unit - buy a new one or send the one I have in for a check.

Any ideas?

Btw: It has a Bosch fuel pump, spin-on oil-filter.

Best regards
Morten H
MHO HOYSETH

Morten, most of us are US spec car guys. there might be a couple of PI guys here. I would hunt down a English TR PI forum. I know there is one I just can't remember its name.
DON KELLY

Morten,
Suggest you change your fuel filter, then try it.
db
Doug Baker

Morten-Most of us carb people wish we had the performance of the PI models without the problems. Try this UK site: www.tr-register.co.uk/forums
If it doesn't work,enter TR register in your search engine.
Berry
BTP Price

Tanks Berry
DON KELLY

Hi

Go to the Triumph owners website www.triumphowners.com and download the Lucas Fuel Injection Manual, it will give you an understanding of the system. One thing you could check is that the Fuel enrichment lever is fully home when the choke is pushed in. This system relies on manifold vacuum for correct metering, check for air leaks ; Low vacuum means increased fuel delivery. Also check that all butterflies are synchronized and that timing and tappet clearances are correct, all effect manifold vacuum. Finally check your compression.

Regards
Colin Norcott
C J Norcott

Where'd he come from, welcome Colin
DON KELLY

Thanks Don
C J Norcott

Just sent a small mercy package to West. Au.
DON KELLY

Hi Don

Mercy package, parts or alcohol? W.A is about 4 hrs flight west of me.

Hi Morten

Any luck with that PI engine yet there are a lot of things to check before you start replacing the metering unit.

Colin
C J Norcott

Hi guys,
Sorry I haven't replied yet! Thanks for all the good advices, I really appreciate it.

I also tried the www.tr-register.co.uk/forums forum, as you suggested Berry, and the first tip was related to the butterflies as you are mentioning here Colin.

At the moment I'm replacing the exhaust manifold (and exhaust all the way) with a Phoenix type. And when I started removing the inlet and exhaust manifolds, I found something new to clean up while I was down there...and yes, I've picked the engine more or less to pieces :) Well, anyway, I'll have it up and running by tomorrow, and then I'll start with:

1) Checking the butterflies and sync.
2) Checking for air leaks

I'll keep you posted - I believe more questions will come :)

Thanks for all help so far!

Morten
MHO HOYSETH

Hi Morten

When checking for air leaks you should make sure you have not got a leak through your brake booster (servo) by disconnecting it and blocking off the hose to the manifold.

Colin
C J Norcott

Thanks, Colin, I'll do that :)

Morten
MHO HOYSETH

Hi folks

The engine now runs smooth as ever - no problems at low revs :) JIHA! The problem was related to the butterflies not being syncronized. A bit of looking,listening and adjustments -> the engine now works (close to) perfect. Thanks guys!

Morten
MHO HOYSETH

Hi Morten

I am glad it is now running nicely for you. How about posting a picture of your car. Below is a picture of mine, still a long way to go.

Colin

C J Norcott

Hi Colin

Ref. your picture - looks great!! Mine is not anywhere close to be as perfect as that.


I've added a few pictures on Flicker as well:
http://www.flickr.com/photos/50366888@N02/sets/72157623978041367/

MHO HOYSETH

MHO, Looking good! What size steering wheel is that?
JT White

Thanks :)

This is a 15" bought from Moss, if I was to buy it over again, I would go for a 14". When I first fitted it, I was afraid that I wouldn't get my legs under it, but that was no problem.

Morten
MHO HOYSETH

I put a 13" on my MG Midget and it was fantastic for leg clearance.
JT White

Hi Morten

Your car looks really good, I hope mine comes up that well. Is the motor from a TR6 or a saloon? I have found another site that you may be interested in, it is totally devoted to Lucas fuel injection systems and contains a lot of information. www.lucasinjection.com

Colin
C J Norcott

Hi Colin,
thanks:) This weekend was the first this year I could actually enjoy driving the car..,except from some minor problems - first the wire to the accelerator pedal tore off (hard to get a replacement on a holiday here in Norway), the day after the slave AND master cylinder to the clutch broke, the next day the bracket for the rear shock absorber "came off" during driving. Puh - what a weekend :)

The engine is a '71 TR6 PI engine, that is at least what I have been told (this is done for 15 years ago).

I'll check out the site you recommended.

Thanks :)

Morten
MHO HOYSETH

This thread was discussed between 11/05/2010 and 25/05/2010

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