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No Pulse on fuel line No. 2


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Dear All

Please help frustrated of Notts!

Car is 1972 TR6 PI

In 2016 engine rebuild, new metering unit, gearbox, overdrive, hoses, injectors - the lot!

Drove to France and back no problem

MOT lapsed in August 2017 but now back on road and last weekend ran very well.

Ran rough this morning, under powered, felt like only 5 cylinders working, checked spark plugs and No2 was fouled.

Checked injectors and no.1 is fine, nice spray pattern but nothing from no.2, it has no pulse! I pinched the tip of injector and a little fuel dribbled out but then stopped.

Pinched the tip several more times but no fuel and no pulsing on the fuel line.

Good pulse to all other but not no2.

I'm no expert but any advice would be welcome please.

many thanks

Richard

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Richard,

 

There is a poppet inside that opens under pressure (50 psi). If you aren't getting fuel through even when pulling on the poppet your problem lies in the pipe or metering unit. Swap the injector over to another cylinder to prove it's not the injector.

 

They sound awful on 5 cylinders so good luck sorting it out.

 

Colin

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Yes as Richard says first swap injector then probable metering unit situation, as its only a rotor, likely a blockage such as o ring or creased pipe unlikely you have a piece if crud the size of a golf ball in there. You will probably need to take the pipe of at the metering unit end so best done by whipping off the whole unit if you feel confident?

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Thanks Colin, will give that a go.

 

Richard,

There is a poppet inside that opens under pressure (50 psi). If you aren't getting fuel through even when pulling on the poppet your problem lies in the pipe or metering unit. Swap the injector over to another cylinder to prove it's not the injector.

They sound awful on 5 cylinders so good luck sorting it out.

Colin

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Hi Rem18

Nope, not confident!

Back to experts me thinks!

 

Yes as Richard says first swap injector then probable metering unit situation, as its only a rotor, likely a blockage such as o ring or creased pipe unlikely you have a piece if crud the size of a golf ball in there. You will probably need to take the pipe of at the metering unit end so best done by whipping off the whole unit if you feel confident?

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Yes sounds like if its a replacement you might have some sort of come back if you havnt driven much and if its not crud from your cars fuel system? Certainly start by swapping injectors but you will need to bleed the system a bit, which needs a tiny bit of expertise....

Good luck

Tony

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I do this with the plugs out (makes a huge difference to the cranking speed) , enrichment lever on full choke, injector pipe rising upward to container then flick the tips of the weak injectors open until the air is released,

 

If this doesn't work there's a check valve in the No. 2 outlet union at the MU that might need cleaning, from memory No 2 is the most likely to get dirty due to its position on the MU.

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Had precisely the same problem a few weeks ago... Turned out it was air in the system (had been running fine before put to bed 3 months previously).... Cylinders 2 and 5 have banjo bolt non return valves fitted... Unfortunately they often dont get changed as part of a metering unit refurb on exchange as they are expensive whereas the valves on the other four are a simple o ring...These can mean air can get in the system on these two cylinders in particular

 

I could not believe the amount of bleeding of the injector needed on mine on cylinder 2 before it sorted it..My technique was to hold the injector vertically as high as I could get it (pin at highest point) hold it with a rag and gently hold the pin open ....and repeat

 

Even after holding it for 30 secs it had still not cleared...Try again and finally a mist came through...

 

Put injector back in the head and bingo instead of 5 we now have 6

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You just need to bleed the injector. Crank the engine over while gently tapping the injector nozzle with a light wooden item like a small screwdriver handle. It might take a minute or two but eventually the air will clear and you will get a fine cone spray.

These cars tend to have an injector air block when they haven't been used for awhile. i had quite a few when I bought mine as it hadn't been used for many years. A local Triumph specialist showed me how to bleed them which I had to do a few times. It hasn't done it now for some time as it is getting run and driven much more often.

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You just need to bleed the injector. Crank the engine over while gently tapping the injector nozzle with a light wooden item like a small screwdriver handle. It might take a minute or two but eventually the air will clear and you will get a fine cone spray.

These cars tend to have an injector air block when they haven't been used for awhile. i had quite a few when I bought mine as it hadn't been used for many years. A local Triumph specialist showed me how to bleed them which I had to do a few times. It hasn't done it now for some time as it is getting run and driven much more often.

Just got back from a shopping trip in the TR. About the worst thing that you can do to the PI system is not use it.

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Two types of injector.

One has a "needle" projecting from the nozzle. Pull on that with fingernails (not pliers!) To release and vent air.

Second has no "needle". That needs tapping.

 

John

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Two types of injector.

One has a "needle" projecting from the nozzle. Pull on that with fingernails (not pliers!) To release and vent air.

Second has no "needle". That needs tapping.

 

John

Thank you. Always learning something new.

I was taught to gently tap the needle, didn't know it could be pulled out a bit.

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Everyone is right here, and yes you can pull with fingers, just dont pull hard and as they have said hold it turned upwards so air can rise, as I am very lazy I bleed with car idling but keep a fire extinguisher handy....... :rolleyes:

You wont get to those criminal bangos without taking the MU off as 2/5 are the culprits, those O'rings are also the ones that degrade first letting air in when car is resting.

The injection is one of the nicest areas to work on and only takes a couple of tries to learn.

But do also feel the pulses on the pipes to learn which injectors are strongest which surprisingly no-one seems to have mentioned...

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Thanks all

Pulled the needle on injector gently with fingers and covered it with a cloth, engine running on tick over.

No fuel and now the needle is "sloppy" in the injector as in it does not spring back in to a tight fit.

Held it open for 30secs or so but there is no pulse on 2 injector line so think it is metering unit fault.

Swopped the 1 and 2 injector and no fuel to no 2 as anticipated.

Have I damaged the no.2 injector as the needle now is loose on its seat?

Will need garage appointment and will provide new fuel filter for fitting at same time.

Richard

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Hi Richard

 

I did the same to my injectors when i bought this car back in 2012.

 

So i sent them off to Injection Guru, Neil Raven Smith

 

For a VERY modest sum Neil refurbished my injectors and shipped them back, very fast service and looking like new.

 

The number 2 and 5 banjo’s are a well known weak point as explained above, but with refurbished injectors my car has run perfectly for more than 5 years now.

 

Mayby contact Neil ( k raven smith ) on here, he’ll sort you out for much less money than taking it to a ‘specialist’ AND you’ll have fixed the problem yourself :-)

 

Steve

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+1 for neil. I took the car to him and he took the mu out, refurbed it, checked all the injectors, reinstalled, bled system and test drove it to confirm all ok in about and hour and a half. He’s not far from you either(near Stafford).

 

Cheers

 

Dave

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Blow the injector through with an airline. Zero cost option and likely to solve most problems. A cut down airbed adaptor makes a suitable too.

 

If that fails (<5%) then the injector need rebuilding or there is an issue with fuel pump or metering unit

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Neil reconditioned mine, including two spares.

Great service.

Cheers,

Waldi

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Thanks all

Pulled the needle on injector gently with fingers and covered it with a cloth, engine running on tick over.

No fuel and now the needle is "sloppy" in the injector as in it does not spring back in to a tight fit.

Held it open for 30secs or so but there is no pulse on 2 injector line so think it is metering unit fault.

Swopped the 1 and 2 injector and no fuel to no 2 as anticipated.

Have I damaged the no.2 injector as the needle now is loose on its seat?

Will need garage appointment and will provide new fuel filter for fitting at same time.

Richard

Richard! Its quite common for the threaded nylon tube to come unscrewed/split inside the injector which controls the tension on the spring/poppet valve. Has this happen to you? I use KMI injectors which now have nyloc nuts fitted instead, have not had a problem since! Have lost 4 injectors that way over the last 5 years!

 

 

Bruce.

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  • 2 weeks later...

Thanks for the posts everyone.

I swopped injector 1 with injector 2 and still no fuel coming through. Put injector 1 back in to correct place and nice spray of fuel coming through in to cylinder 1.

Seems to be a problem within the metering unit? Got good fuel delivery to all other injectors but not 2.

Mansfield Engines who did my engine rebuild in 2016 took 2 and 5 banjo bolts out of unit but both clear. (too tricky for me)

No apparent or visible blockage so could be within metering unit?

If so, can anyone recommend metering unit specialists in Notts area please.

TR Enterprises is only a few miles away - any thoughts?
Thanks

Richard

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Neil Ferguson (k raven-smith on here) is at Stafford he does a first class job 07977001571.

Stuart.

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