Testing Diesel injectors
 

What tests can be carried out to check if an injector for a diesel is any good?
I have seen two things on YouTube, testing the ohm resistance and a leak back test.

What should the ohm resistance be?
What is the step by step test for leak back testing? The video showed the engine being rev'ed for 30 seconds at 3,800 revs then this and that.

is there any connection between the results of ohm resistance and leak back, by this I mean if ohms is in spec what can I expect from leak back or are they completely independent of each other?

thanks

macafee2

Completely independent Ian. You need the proper equipment to test injectors fully. Mickyboy has it and the expertise to use it but I don't know if he offers it as a service.


Steve (Arctic) has a good how to for checking leak back.

Got a feeling I spoke to Mickyboy a couple of years ago and no he does not or did not offer the service then. I am not having trouble with my injectors but if the injectors are good on the car I was given, then I know I have spares should I ever need them,

Hoping upper arms and exhaust are good on it. Wheels will be used with winter tyres.

macafee2

Hi Ian
Same link as i posted on your other thread, well worth purchasing one of the below while they are cheaper, usually £25+
https://www.ebay.co.uk/itm/144149776...ef1a%7Ciid%3A1

They are easy to use, just remove your original T joints on top the the injectors by pressing in the spring clips, lift the joints off using some pliers on the square and tug upwards.

Then replace with the kit joints, remove the leak back hoses with joint at the end of the hose, then clamp off that hose, put it into a container or pop bottle with the head cut off.

Start car and see how long it takes to add fuel into the small bottles run the car on tick over for about a minute you are hope to have none or no more than 20mil in each bottle in that time, take notice of which one fill up faster that then gives you and indication of which injector is leaking more than the others.

This photo be low only took about 20 seconds to fill the bottle
https://i.imgur.com/IHnerSXl.jpg1

https://i.imgur.com/H67oK67l.jpg2

https://i.imgur.com/o9FhpPxl.jpg3

You will only be using four of the six bottles, you can see from photo 1-3-4 have not even got any fuel in then in the time it took to add 70mil to bottle 2 from injector 2
https://i.imgur.com/510XIObl.jpg4

So an undeniable conclusion which injector was leaking and making the car hard to start.

Arctic, thank you I appreciate you taking the time.
am taking the plunge and ordering the kit in your link. Not too expensive and it will be good experience to try a test.
Just as well yo told me to clap the hoses I removed as I would not have done.

thanks again

macafee2

Ian.
Yes clamp off the return hose once you have removed the T section from the injectors and the return hose.
https://i.imgur.com/45ohPnUl.jpg1

As you can see from photo above i made up a clamp that you can just push into the hose, but you can just clamp the hose with something or at least put a stop into then end, then put the hose into a bottle or container, another tip if you are going to remove the injectors for keeping make sure the engine is hot as this helps with removal, cold injectors can be harder to remove.

Also remember once removed the car will not start, so make sure you have it in a position that it will not need to be moved, and you can gain access to all sides of the car ;)