Blocked injector

[John McCormack]

A bit of am unusual one today. I had a blocked injector, 3rd time I have had one in 2 and a bit years ownership. I drove her home about 20kms and only a 10 minute job to clear it but annoying all the same.

The past two were on 2 or 5, the usual culprits. This time it was number 6.

I had just filled her up but it wasn't near empty, from about 1/3 of a tank, so that shouldn't have stirred up any debris in the tank. 

[Mike C]

Anything stirred up in the tank should have been caught by the main filter. Do you still have  the  filter fitted to the MU inlet union?

Personally I find that  Australian high octane unleaded is becoming increasingly aggressive towards fuel system components-elastomers that were fine 10 years ago (various grades of nitrile etc) are now  being attacked, especially by stale fuels.

[John McCormack]

7 minutes ago, Mike C said:

Anything stirred up in the tank should have been caught by the main filter. Do you still have  the  filter fitted to the MU inlet union?

Personally I find that  Australian high octane unleaded is becoming increasingly aggressive towards fuel system components-elastomers that were fine 10 years ago (various grades of nitrile etc) are now  being attacked, especially by stale fuels.

There are filters between the tank and the Bosch pump, the main filter is between the pump and MU and the small one in the MU. All are quite new and/or cleaned in the past few hundred miles.

Interesting observation on stale fuel. I had been away for 11 weeks and the TR6 was left with about 1/3 tank. When I got home I took her for a quick drive and filled the tank up before setting off for another almost two weeks away leaving the 6 at home. I have been using it solidly for the past week or so before this occurred using most of a tank which is why I had just filled up.

The previous blocked injectors occurred in the first 6-12 months of ownership and it has been about 18 months since it last happened. I thought the past ones were because the car hadn't been used very often for many years and I had it sorted.

Not much I can do except bleed them as they occur. I do need to carry a spare or two in case one breaks while I am bleeding it.

How do you fit a new one to the pipe while beside the road?

[Mike C]

I add  Stabil whenever I expect to leave the car stored for more than a month or so, I've had too many bad experiences with stale fuel.

I don't see any point in carrying spare injectors.I've experienced a small fire while bleeding an injector with a running engine but never broken one, the fire almost burned through the nylon line which would have caused a major drama. Maybe cross threading the injector line nut could cause a problem on the side of the road.

In any case I normally limp home with missing cylinders then try the Lucas air blowback trick before I start bleeding etc.

[astontr6]

1 hour ago, Mike C said:

I add  Stabil whenever I expect to leave the car stored for more than a month or so, I've had too many bad experiences with stale fuel.

I don't see any point in carrying spare injectors.I've experienced a small fire while bleeding an injector with a running engine but never broken one, the fire almost burned through the nylon line which would have caused a major drama. Maybe cross threading the injector line nut could cause a problem on the side of the road.

In any case I normally limp home with missing cylinders then try the Lucas air blowback trick before I start bleeding etc.

Problems of blocked injectors 2 &5 are usually down to the 'O' rings on the non return valves starting to break up and if trouble is experienced on  another like number 6 that is the bung 'O 'ring starting to break up. It is made worse if the inline filters are missing from the injectors as new ones are un-obtainable. As already said modern petrol is very aggressive. When removing any of the non return valves from the M/U only use a ring spanner otherwise you will burr the hexagon very badly as they are normally very tight.

Bruce.