How to test injectors ?

[Briv6]

I have a misfire and lumpy idle . Had the car on clip a few days ago and there was no fault stored so they checked connections of plugs leads and everything was ok for 1 day and then it returned . So now having changed the plugs leads and coil and no answer from clip diagnostic , how do I check the injectors ?

Do they sit at front of engine block on a rail ? And would unplugging them one by one when engine is running be sufficient means of testing ?

 

[Chip-mk1]

Resistance meter is first way to check they still make a circuit at the appropriate resistance (around 13 ohms)

Next you can check the wiring is firing with noids.

Then flow test is the final step, send off is easiest way although it can be ghettod if you want.

 

[Briv6]

So pulling them out and seeing if any make a difference isn't worth trying ?

Im in no way a mechanic so anything is out with my abilities

 

[Chip-mk1]

To test that way you would just unplug them electrically.

You can't physically pull them out as the rail would piss fuel out at high pressure.

 

[Briv6]

Ok maybe I'm out my depth

its just getting a good mechanic to my house that's the problem , I don't like driving a car with misfire .

 

[Chip-mk1]

Where abouts are you?

 

[Briv6]

Scotland west lothian

 

[Chip-mk1]

An i don't know anyone there to recommend to help you. Sorry.

 

[jonny172clio]

I'd suggest pulling out the electrical plugs individually. Listen for idle change etc and you could narrow it down hut for the price you could afford to get 2 I did mine and when I took out the fuel rail you could see which one was knackered as the other 3 were nice and shiny and the knackered one was a bit brown and gunky I got mine from renparts 32 each...

 

[jonny172clio]

Really easy to change aswell 4 nuts, pull out fuel rail fit new injectors and pop the 4 nuts back attach fuel line done take you about 15minuyes to change all 4

 

[Briv6]

Ok thanks for the advice ... What do u mean by electrically ?

 

[Chip-mk1]

Unplug the wiring plug from injectors. Not remove injector.

 

[Fraser.J.]

I unplug the 4 injectors from the inlet and look to see which one isn't firing.

 

[jonny172clio]

Yeh as said just unplug each one individually don't take them out totally just unplug the electrical socket attached to each one so u know which one has gone. It will idle the same if u take out the one which is broke and probably cut out if u unplug one which is working

 

[jon_r]

Bet it's number 3.

 

[JD]

Chip mentioned flow testing in the first reply - I'd suggest that might be a good route to go down. As my car is 12 years old, I'm sending mine off to this guy soon;

http://www.ebay.co.uk/itm/Fuel-Inje...arts_Vehicles_CarParts_SM&hash=item258981423e

That price is per injector, so total cost is £45 ish quid plus postage to him.

 

[Chip-mk1]

I use these guys:
http://injectortune.co.uk/

To test only is 5 quid an injector plus 7 quid post.

So 27 quid for 4


Cleaning is extra.

 

[Briv6]

Bet it's number 3.

I bet you are right ! Just had it checked and injector no3 the problem