Injectors, Where, How, And Why?

[johny105_y2k 1]

Right well basically,

How do you tell when they're no good.

i'm in the process of rebuilding my engine and have 8 injectors 4 from this engine and 4 from an old engine.

i want to try and nip any problems in the bud before they occur.

the main reason i ask is some of the ends are 'browned' and others arent .

 

any ideas without testing

is there a resistance value or something???

 

much appreciated

johny

[Tom Fenton 1,542]

You can test an injector yourself by wiring 12v across the coil, and then feeding it with fuel at rail pressure, and then see how much it flows in a minute, as this is how injectors are rated. You can then compare this against what they should flow and see where they are. This is a ballache on its own TBH as there is a fair bit of rigging up to do to be able to do it. What is harder still is applying a vacuum downstream of the jet (as this is how the injector works in the engine, as there is a vacuum past it in a NA engine) and watching how the stream of fuel coming out then looks, seeing if it is even etc.

 

Or you can forget all the above, and pay about £8 per injector and post them off to be professionally cleaned, tested, filter baskets and o-rings changed, and sent back to you. Thats the option I have and would choose.

 

Finally you can forget both the above options and see if they work in an engine. They will either open or they will not, past that you've no idea how well they are working.

[Rom 0]

Ive never tested any myself, as im far too lazy

Getting them cleaned is the best bet. Its not overly exspensive, and youll hopefully end up with better quality than simply working injectors. Along with a nice printout to show any improvements / problems.

[rubyna 4 1 Cars]

Anyone know of a reputable company who refurbs them?

[Rom 0]

I used Lucas, as didnt have time to send them away. Dont know if all branches can do it though.

Lots of people have used places off the net, but not sure of specific names.

[johny105_y2k 1]

You can test an injector yourself by wiring 12v across the coil, and then feeding it with fuel at rail pressure, and then see how much it flows in a minute, as this is how injectors are rated. You can then compare this against what they should flow and see where they are. This is a ballache on its own TBH as there is a fair bit of rigging up to do to be able to do it. What is harder still is applying a vacuum downstream of the jet (as this is how the injector works in the engine, as there is a vacuum past it in a NA engine) and watching how the stream of fuel coming out then looks, seeing if it is even etc.

 

Or you can forget all the above, and pay about £8 per injector and post them off to be professionally cleaned, tested, filter baskets and o-rings changed, and sent back to you. Thats the option I have and would choose.

 

Finally you can forget both the above options and see if they work in an engine. They will either open or they will not, past that you've no idea how well they are working.

ok thats fair comment.

as for who to do it, if you do a search there must be 20posts on who can do it and who can supply new ones aswell.

i just wanted to know if you could test them..

 

thankyou johny

[welshpug 1,657]

I know Dave Walker at emerald does it, and there's a place in Devises that advertises on ebay too.

 

Most garages have a contact they use, pop into your local garage and ask.

[KRISKARRERA 2 1 Cars]

and there's a place in Devises that advertises on ebay too.

Yup, he's a mate and does a good job.

[welshpug 1,657]

so does your car start properly hot or cold now kriss?

[KRISKARRERA 2 1 Cars]

Yes

[Rupertfinch 6]

Last Months Practical Performance Car magazine had an article on building a DIY ASNU - the injector testers that garages use (given the hilarious title ARSENU). It looked a wee bit too complicated for me but they did suggest using an ultrasonic bath and some white spirit to help clean them, I thought this was a good idea!