Clogged injector tricks whilst on a drive

[Steve-B]

(I've searched archives but can't find a simple trick)

I've been out on drives over the weekend and had an injector sputter. By sputter, I mean the engine kind of sputtered a bit on accleration vs. a free flowing supply of fuel so that made acceleration a bit less.

I've heard you can go up a gear, then drop 2 gears and sometimes the MFU increased pressure will help clear. Others have said you've go to pull over to side of the road, feel which fuel injector line from the MFU isn't as strong, grab 1/2" spanner and take it off to clear it out.

I understand TADTS but was hoping someone may know of a trick to do whilst driving so don't have to pull over. If there isn't one, that's ok, but wanted to check with the collective

[Mike Collins]

Very occasionaly I have cleared one by going full rich, but the answer is to carry a spare unless you can access compressed air.

Mike.

[harlequin]

Not exactly in line with current elf and safety guidelines, but I have had success by gently tapping the injector on the block with the ignition on untill the spray pattern returns to normal.

George 

[Nigel Triumph]

3 hours ago, Mike Collins said:

Very occasionaly I have cleared one by going full rich, but the answer is to carry a spare unless you can access compressed air.

Mike.

+1

Mike's suggestion has worked for me occasionally. Full choke and floor the throttle.

I've also had a blocked injector clear itself after 5-10 miles at 70mph, following much stuttering at lower speeds, which failed to clear for around 40 miles before.

Nigel

[Paul Hill]

You could carry a stirrup cycle pump it always blew the **** out of my injectors till I fitted the new tank

[Andy Moltu]

Footpump with an air bed adaptor to blow it out.

[Bill944T]

Or you could make up an adapter to fit onto the spare tyre valve and use a little of that pressurised air… I can’t recall the make/model car that used this method for the windscreen washer rather than an electric pump.

Regards

Bill 

[HSM]

VW Beetle, the tyre was inflated to 50 psi with a cut off valve at 30 psi to prevent the tyre being flat when required.

                                      Harvey

          

[Rob Salisbury]

So long as Mr 'Elf n Safety isn't looking, pull the offending injector out of the TB and, with the engine running, (if you have the type with a pintail at the end) gently pull the pintail out slightly with a pair of long nose pliers to allow extra fuel to spray out, unless the injector is properly goosed then this method usually works.

Cheers Rob 

[CP26309]

I always make sure I get the injectors with the 'Pintail'. I find I can pull these with my finger and thumb nails. But yes always carry spare injectors. I'll try that full rich trick next time! For testing injectors I use a jam jar with a hole in the lid. 

[roy53]

23 hours ago, harlequin said:

Not exactly in line with current elf and safety guidelines, but I have had success by gently tapping the injector on the block with the ignition on untill the spray pattern returns to normal.

George 

or tapping with a spanner when the engine is running

Roy

[Steve-B]

 Thanks gents, I’ll certainly try some if not all of the above when it next happens whilst out.

Lucky for me it was grandson’s first ride out, so he’s none the wiser, yet  

PS> I do plan to send the injectors off for a clean / rework  at first sign of gritting the roads!

[Andy Moltu]

The use of tyre pressure to blow out the injector probably won’t work.

The injectors when working normally should pop open at 50psi so a blocked one, which isn’t opening at 50+ psi, may need far more pressure than that to blow clear, perhaps as much as 100psi which your spare won’t take.

[Nigel Triumph]

13 hours ago, Andy Moltu said:

The use of tyre pressure to blow out the injector probably won’t work.

The injectors when working normally should pop open at 50psi so a blocked one, which isn’t opening at 50+ psi, may need far more pressure than that to blow clear, perhaps as much as 100psi which your spare won’t take.

I've used a tyre foot pump to successfully unblock and injector in the past, before I bought a cheap compressor for my garage.

Nigel

[Andy Moltu]

I use a foot pump and an old fashioned airbed adaptor with the very tip cut off. Being plastic if you shove it into the injector it makes a decent seal and a couple of stamps on the foot pump generally does the trick.

So many injectors get sent for rebuild when the only problem is a bit of debris jamming it.

[rcreweread]

One of the best bits of kit I have bought in recent months was a 12V Cordless Mini Air Compressor from Aldi  and I see they have just halved the price from £30 to £15  - absolute bargain

https://www.aldi.co.uk/12v-cordless-mini-air-compressor/p/808783560995201?utm_source=Aldi&utm_medium=Email&utm_content=12v-cordless-mini-air-compressor&utm_ca

Might very well blow out injectors as well as pump up your tyres etc

Cheers Rich

[astontr6]

On 10/3/2022 at 3:41 PM, Steve-B said:

(I've searched archives but can't find a simple trick)

I've been out on drives over the weekend and had an injector sputter. By sputter, I mean the engine kind of sputtered a bit on accleration vs. a free flowing supply of fuel so that made acceleration a bit less.

I've heard you can go up a gear, then drop 2 gears and sometimes the MFU increased pressure will help clear. Others have said you've go to pull over to side of the road, feel which fuel injector line from the MFU isn't as strong, grab 1/2" spanner and take it off to clear it out.

I understand TADTS but was hoping someone may know of a trick to do whilst driving so don't have to pull over. If there isn't one, that's ok, but wanted to check with the collective

In my experience of 40+ years of ownership, the main problem of splutter has been caused by air and not crud in the system. This has only happened once when the O rings started to break up in the M/U. I am still using the small gauze filters in the injectors.

Bruce.

[Steve-B]

11 hours ago, astontr6 said:

In my experience of 40+ years of ownership, the main problem of splutter has been caused by air and not crud in the system. This has only happened once when the O rings started to break up in the M/U. I am still using the small gauze filters in the injectors.

Bruce.

Bruce, I appreciate your point however if it is just one injector, would that mean when it next occurs should the clearing ideas earlier in this thread not do the trick you believe i need to rebuild the M/U?

[astontr6]

23 hours ago, Steve-B said:

Bruce, I appreciate your point however if it is just one injector, would that mean when it next occurs should the clearing ideas earlier in this thread not do the trick you believe i need to rebuild the M/U?

There is an O ring in the base of the M/U where the non-return valve is screwed into the body of the M/U they start to break up and bits of rubber get collected in the injector gauze filter if it is still there. To my knowledge none of the injector reconditioners supply injectors back with them in which to me is a major oversight.

Bruce.

[Steve-B]

On 10/9/2022 at 9:55 AM, astontr6 said:

There is an O ring in the base of the M/U where the non-return valve is screwed into the body of the M/U they start to break up and bits of rubber get collected in the injector gauze filter if it is still there. To my knowledge none of the injector reconditioners supply injectors back with them in which to me is a major oversight.

Bruce.

That sounds like a good winter's night project to invest time in Bruce. Are replacement o-rings and gauze filters parts hard to source?

[astontr6]

52 minutes ago, Steve-B said:

That sounds like a good winter's night project to invest time in Bruce. Are replacement o-rings and gauze filters parts hard to source?

The O rings are obtainable, but the gauze filters are not but I consider them essential as they stop the rubber crud from getting stuck on the injector valve seats. 

Bruce.

 

[Steve-B]

23 hours ago, astontr6 said:

The O rings are obtainable, but the gauze filters are not but I consider them essential as they stop the rubber crud from getting stuck on the injector valve seats. 

Bruce.

 

Has anyone written up how to create a suitable replacement filter? I searched but didn't find anything... OR I wonder if I can source some whilst in the USA soon?

Edited October 11, 2022 by Steve-B

[Kenrow]

Sorry, I doubt you'll find them in the USA. Both Moss and TRF (the main venders here) list them as NLA.  

[astontr6]

On 10/10/2022 at 4:13 PM, astontr6 said:

The O rings are obtainable, but the gauze filters are not but I consider them essential as they stop the rubber crud from getting stuck on the injector valve seats. 

Bruce.

 

I think that the Register should put pressure on Moss to have them remade. They were also fitted in the fuel line by the M/U.

Bruce.

[John L]

Have you tried contacting KMI, I think they do still make new and recon injectors.  https://kmipetrolinjection.co.uk/Lucas Mk 2 Petrol Injection.htm

John