Jump to content

Recommended Posts

Hello I am having trouble with starting my tr6 there is good spark at plugs and points, injectors have been refurbed when I try to start the plugs get flooded, I have bled the injectors as instructed the engine seems to try to start on 1 or 2 cylinders and then nothing and the plugs would be wet when removed. I am getting frustrated.  

JLEpy

 

Link to post
Share on other sites

Are all plugs wet (are all injectors spraying)? Venting all is important.

I found that plugs, once they have been wet, do not work well. I installed new plugs.

Waldi

Link to post
Share on other sites

Have you checked the metering unit's vacuum diaphragm for leaks? ..... pull the inlet manifold end of the link tube and check with a vacuum gauge or more simply (but a bit unpleasant) suck and apply the tongue test. ....... If the diaphragm is leaking then the metering unit will deliver the maximum fuel quantity and simply flood as the engine tries to start.

Cheers Rob    

Link to post
Share on other sites

Is this after a long lay up, or has it recently just gone from starting well to won't start? 

What's the state of the fuel, has it been in the tank for months or days? 

Is the timing close to being at the right point? Are the plug leads in the correct positions? 

If the fuel is new and your happy with the ignition side, and all injectors spray correctly, then I'd change plugs, charge battery. Now pull choke out to full and if it fires up push choke in about half way and see if it will stay running. 

Gareth

 

Link to post
Share on other sites

This happened to my car which had been rarely used before I bought it.

The easiest thing to check for flooding like this (and the most likely cluprit) is the enrichment lever on the metering unit. You will see it where the cable attaches to it on the engine side of the metering unit.

Put your finger down between the block and the metering unit and you will feel the actual lever (the cable is attached to an extension). Push this lever very hard towards the back of the engine. I am confident you will feel it move back to the off position.

Spray lots of WD 40 or equivalent down there and moved it backwards and forwards for a few minutes. It should lubricate it and free it up. Mine hasn't had a problem for 3 or so years now.

Link to post
Share on other sites

Hi all thanks for your suggestions, I have changed the plugs, checked the injectors they have a good spray on them, the enrichment lever seems to be working as it should there is 5mm play between the cable attachment and the lever which moves back and forward ok, the fuel is quite fresh I tried to start the car with no choke the engine fired up then petered out i did this 3 times with the same result I tried with choke and not much firing going on. I have what I think is the vacuum pipe I removed the pipe sucked on the pipe there was resistance I put my tongue over the end of the pipe and felt pressure  sucking my tongue in, is that correct reaction. I have not touched the timing. 

Many thanks 

JLE       

Link to post
Share on other sites

I would be inclined to do a fuel pressure check in that case as your PRV maybe stuck hence the over fuelling.

Stuart.

Link to post
Share on other sites

Ah, sounds as if the tongue test has revealed a good diaphram, next thing that may cause overfueling is the little plastic link piece from the diaphragm to the roller carriage deep inside the metering unit, these do break over time, if you are brave you can check this by removing the black plastic cover on the side of the metering unit (4 screws and it's off), but if it's a newly supplied unit this will invalidate any warranty you may have, .... an old one? ...  just take it off and have a look.

Cheers Rob 

Link to post
Share on other sites

It would be a good idea to have somebody in the club give you a hand before you start stripping down the metering unit. The TR6 is usually very reliable and quite simple. Where are you? Have a look here and get in touch with your local group: https://www.tr-register.co.uk/groups

Mick

Link to post
Share on other sites
On 3/27/2022 at 12:19 PM, Waldi said:

Are all plugs wet (are all injectors spraying)? Venting all is important.

I found that plugs, once they have been wet, do not work well. I installed new plugs.

Waldi

A trick from my motor cycle 2 stroke days! If the plugs foul through getting wet, hold the plug with a pair of pliers and put the electrode in the flame on a gas hob unit. Then put the plug back in hot. This always worked for me? Still use this method on my 2 stroke strimmer!

Bruce.

Link to post
Share on other sites
25 minutes ago, Johnthelms said:

...and how can I check to see if it is stuck...

Ideally you need to test the fuel pressure that's arriving at the metering unit. This is done by adding an appropriate pressure gauge and fittings and should read 104 to 106psi while pump is running. 

20210823_094820.thumb.jpg.d8fbc5dfbea1244d748d5f4425442d31.jpg

Link to post
Share on other sites
2 hours ago, Johnthelms said:

Hi thanks for all the information, I presume the PRV is pressure relief valve where do I find this and how can I check to see if it is stuck, Rob I am not brave enough to delve into the metering unit.

Many thanks everyone I will keep persevering 

JLE

In case you are not sure what a PRV looks like, here is a photo of 3 different used ones - I didn't know what these were either till I was told recently - they are all PRVs - not what I'd expect!

cheers Rich

image.png

Link to post
Share on other sites
9 hours ago, Mike C said:

i don't like testing mine with petrol. For my car to run properly I need to set the PRV to open at 680 kPag with air. But , after 50+ years of modifications , every PI system is now different.

Air and liquids will give a different  pressure readings???

Bruce.

Link to post
Share on other sites

When I got my car in 1972 it often wet up a plug until I learned not to give it too much throttle or cold start (choke) when cranking. if it didn't clear itself on a run I'd pull the plugs until I found the culprit and swapped it for one of the hot ones and all was well again. These days just starting it up for it's once a month run I find I have to keep the starter engaged while cranking for ages until enough cylinders catch to run with out being chased by the starter motor! But it's still quite a art to get the least amount of throttle and enrichment to avoid plug fouling.  

Link to post
Share on other sites
7 hours ago, CP26309 said:

When I got my car in 1972 it often wet up a plug until I learned not to give it too much throttle or cold start (choke) when cranking. if it didn't clear itself on a run I'd pull the plugs until I found the culprit and swapped it for one of the hot ones and all was well again. These days just starting it up for it's once a month run I find I have to keep the starter engaged while cranking for ages until enough cylinders catch to run with out being chased by the starter motor! But it's still quite a art to get the least amount of throttle and enrichment to avoid plug fouling.  

Are you certain that your coil/ condenser/rotor arm are in good order? If its a black rotor arm bin it for a red one! Coils can give aggro when they are starting to fail, I have assumed that you do not have electronic ignition as that may also be a problem area? It may also be advisable to do a compression check both hot & cold. Where are you un the UK?

Regards,

Bruce.

 

Link to post
Share on other sites

Hi all I have managed to start the car, I cleaned and set the points, heated the plugs and it started but it only runs for 2-3 seconds coughs and splutters and stops. I have been in touch with a local tr member who has recommended someone to have a look so that will be my next move. Many thanks for all your input.

JLE 

Link to post
Share on other sites

Good move, I'm sure they'll figure it out, be sure to update the thread on what eventually solves the problem. 

Cheers

Gareth

Edited by Mk2 Chopper
Link to post
Share on other sites
On 3/31/2022 at 7:19 PM, astontr6 said:

Are you certain that your coil/ condenser/rotor arm are in good order? If its a black rotor arm bin it for a red one! Coils can give aggro when they are starting to fail, I have assumed that you do not have electronic ignition as that may also be a problem area? It may also be advisable to do a compression check both hot & cold. Where are you un the UK?

Regards,

Bruce.

 

My original Distributor (with points) was last overhauled by Martin the 'Dizzy Doc' back in 2013, at a cost of £237. that's was only about 2,000 miles ago. 

Denis in Hertfordshire. 

Link to post
Share on other sites
14 hours ago, CP26309 said:

My Engine was last rebuilt in 1979 at 61,600 miles, that's less than 14,000 miles ago. 

I would still do a compression check. Were you the person who did the rebuild? or was it the PO? As your engine was rebuilt in 1979 I doubt that the valves are S/S  and the valve seats may be burnt? Change the coil and see if you can get the spark to jump 1/2" to earth if you cannot this points to a faulty coil!

Bruce.

Bruce.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.