TR6 fuel issues

[Wayne Scott]

Posted on behalf of a member, Guy, who posted in rebuild blogs in error: 

Guy says;

"My TR6 has recently had a new Fuel injector and overhauled fuel pump and fuel tank. Probably within last 18 months. recently the engine feels like it is either being starved of fuel and/or an electrical issue, as the engine is no longer smooth sounding when accelorating, and instead is juddering and less power. Any pointers ? It did this before when I ran the fuel tank quite low. This time fuel tank was a quarter full. I would assume due to overhauled fuel tank that it would not have years of bits in."

[ntc]

Wayne

Need more info,do we not have a tech team on the home site anymore?

[Mk2 Chopper]

Good cone spray from all injectors? fuel pressure correct? Spark plug condition? Coil? Points? Timing? Fuel age? 

Plenty of things to check. 

Gareth

[Stagpowered]

Sounds more like an ignition problem to me, weak sparks blow out under acceleration.

 

Neil

[Mike C]

Does the missing not occur  when the tank is full?

[rcreweread]

Hi - when Wayne says " overhauled fuel pump and tank", what was done to the tank ? Was it new ,  treated with slosh tank sealant  or similar  - you might be getting debris in your fuel lines/tank outlet if  it wasn't new

Cheers

Rich

[Mike C]

If I installed a new tank and fuel system  I would expect the filter to be blocked early just due to debris in the new components. Easy to change and see if things improve.

[astontr6]

On 8/19/2019 at 8:02 PM, Mk2 Chopper said:

Good cone spray from all injectors? fuel pressure correct? Spark plug condition? Coil? Points? Timing? Fuel age? 

Plenty of things to check. 

Gareth

+1 and were the injectors bled  properly? as there might still be air still in the injector pipes a very common problem after pulling the PI system a part and refitting! Check that pulses can be felt in all injector lines first?

Bruce 

[GUY BENNETT]

Mine used to miss fire at higher revs. Cured by new spark plugs. 1 was breaking down.

Could be leads, cap, rotor etc. 

[Misfit]

I was followed by a friend, apparently there is a terrible smell of fuel, car when starts takes a couple of minutes to fire on all cylinders from cold, but always has. Lately it has taken a little longer. But runs well when warm but still smells. I noted that 4,5,6 plugs are a little sooted up when checked.

But as I said when warm fine so far, any suggestions?

[John L]

Unbalanced throttle bodies, or injectors not spraying properly.

Have you checked if the MU holds vacuum or it will run rich.

Could also be the nylon bearing on the throttle shaft not being there, so not opening the rear butterfly as much.  Heat usually destroys them.

If you take off the black cap on the MU, mark where its orientation, unlock the large ring, and turn the whole lot anticlockwise 1/4 of a turn, and tighten the lock nut again, and refit the black cap, I'm sure it will run better, if not put back to where you started. This will weaken the mixture thru the whole range.

John

Edited August 26, 2019 by John L

[Waldi]

Hi Derek,

following John’s remark about the original (white) nylon throttle linkage bearings, those are relatively easy to check and replace by PU (blue) bearings, Moss and others sell these. 

It requires removal of air plenum and linkage, and off course adjusting the linkage and balancing the 3 TB’s during re-installation. While you are at it (if you will have a go), I would also replace the original 3 vertical linkages to each TB by the ball version most suppliers also can provide you with. It makes balancing easier.

To avoid unnecessary work, I would do the simple (cheaper) things first: check balancing of TB’s, spark plugs, valve gaps, compression ratio.

The rear cylinders are know to run a bit more rich anyway.

And there are no classic cars that don’t “ stink” compared to moderns, unless you love them:).

Regards,

Waldi

 

[Misfit]

JohnL & Waldi

Thank you for your quick response,  l will let you know the outcome.

cheers Derek