tr4 TR4 splutters and dies

[MKTR]

Hi all, Had a nice drive this weekend but after an hour the car started to hesitate and loose power. Pull over and take a look but nothing obvious so carry on for another half an hour and then same happens again. Found some crud in the fuel pump bowl so cleaned that out and set off again. Another half an hour and stuck in traffic and the car almost dies and sounds like she is on a couple of cylinders - limp into a car park and she dies completely.

 

Remembering some similar issues on the forum I checked the distributor, coil, leads and so-forth and all seemed OK. So started to check the fuel side. There was no fuel past the fuel pump and even hand priming was a struggle - but she did fire up and run for a few seconds after priming. I found that fuel was pushing along the pipe to the fuel pump bowl so I suspected the pump diaphragm - but taking the pump apart shows that it is OK. Reassemble and all is well.

 

Drive back home the next day and she is flying for a good hour and a half until we are held up in traffic again and the problems start all over and I am lucky to find a parking slot before she dies again. Same issue - no fuel past the pump not even with hand priming. Take it all apart and blow out pump valves and all is well again.

 

I have done longer drives before and in hotter weather with no issues at all so I cannot see that there is any problem with the fuel line around the engine or fuel vaporisation.

 

My query (at last) - could this have been related to the seating of the fuel pump valves or even some fine crud in the valves or is this just coincidence. Perhaps it is just the time that allows for some cooling? Perhaps I should still suspect the fuel tank even though fuel comes out of the pipe when disconnected?

 

Grateful for your thoughts.

[Steves_TR6]

Do you have a fuel filter before the pump, if so perhaps it's blocked?

[Lebro]

Could be crud in the tank blocking up the exit pipe. When you remove the pump suction is lost, & the crud moves away for a bit.

I had this in my old Hillman, ended up flushing the tank through several times, & fitting a filter inside the tank on the end of the pipe.

 

Bob.

[derekh]

I remember a friend having a similar problem years ago (not with a TR). It was eventually traced to a blocked vent hole in the filler cap. A vacuum would build up in the tank and eventually the fuel pump could not pump against it. Stopping for a while allowed the vacuum to dissipate and all was well for a few miles. Could this happen on a TR?

 

Derek

[ianc]

Filter between tank and pump is not a good idea - under suction, the internals of the filter can collapse and block the flow (as Roger Hogarth will tell you!).

If necessary, fit filter between pump and carburettors, where it will be under pressure.

 

Because of the long delay between starting and dying, the blocked vent hole seems the most likely cause. But do check the filter bowl for yet more rubbish and if that's the problem, refer to my article in Section K3 of the Technicalities CD.

 

Ian Cornish

[tim hunt]

+1 for a vacuum having built up in the tank. Next time the car dies hop out and immediately

open the fuel cap - if it doesn't pop open as it should and when it does you hear a sucking

noise there's your answer.

 

Tim

[MKTR]

Thanks for the replies so far - I can check the tank vent pipe to see if it is free flowing but I am not convinced it is vacuum as when I disconnected the fuel pipe at the pump end it gushed out. So maybe back to considering tank outlet blocakge.

 

Mark