leak back injector test

hiya.

firstly may i really apologise for being a royal pain in the butt.

unable to find a full step by step guide of how to test the injectors.

if i beg on bended knees would anyone be so kind to tell me how to perform this test and what to look out for please.

i hear about the maf sensor is there anyway i can test it or just change it as a matter of course.

if i did find any of them leaking back would millers make any difference please.

the cheapest ive seen for recon inj is 106 from kent diesel

thanks guys and i really do apoligise for asking

all the best

gary

send them to Uncle CharlesY. PM him first tho .

stop apologising, you're not being a pain, we're here to help each other.

I think the leak back test can be done by unplugging the fuel return lines from the injectors and turning the ignition on. If fuel dribbles from the injector then it's faulty.

this may be wrong, so don't do it yet. there was quite a comprehensive thread on here about it, I'll have a dig about

Disclaimer: i can't remember where i found this, or who Keith (who created it) is, so apologies for posting without permission, but its the best explantation of how to do a leak check ive seen.

Bosch Injector Leak Check http://definiteuncertainty.com/bosch_leak_check.pdf

thanks, i read the post with the bottles and to be honest got very confused , i think its because the pics dont relate to a freelander.

have tried searching on here but cant find anything.


optimus you say about the following test, sorry to be a pain did you happen to find anything yet please

I think the leak back test can be done by unplugging the fuel return lines from the injectors and turning the ignition on. If fuel dribbles from the injector then it's faulty.

thanks again guys.

gary

I have done the leak back test using nothing more than a piece of softish rubber (old inner tube) to block off the individual return pipe.
Take off the clip holding the pipe and remove the plastic connector. Dont break it as they cant be obtained except as the whole pipe run. Cut the rubber so that fits on to the top of the injejctor. Then press the connector on to the rubber and ask her indoors to crank the engine. If the seal has gone fuel will rise quite quickly from the top of the injector. If it oozes out slowly the injector is OK. Repeat the action on the other injectors.
I found that I could not hold the rubber on to the connector using thumb pressure as I could not obtain a good seal, hence the need to press it squarely on to the top face of the injector.
I know that this method does not show how balanced the injectors are but it has enabled me to determine which one is down on two different occasions and does not entail the cost of the plastic jars ~£30.

What is the reason for doing the leak back test, as you only need to test if you have a non starting problem. If it is a problem with running then the best was is to take it to a good independant and get them to hook it up and run live data, that will show any injector problems expect to pay around £30. If you tell us your sypmtoms then we may be able to give a bit more advice.

And follow this guide if you want to test

Simple way it to take the return pipes off the top of each injector clamp the return pipe off. Turn the ignition on you should see no fuel coming out of the injector till about 8 seconds. If any leak before that, then that will be the faulty injector. It may be that you get a couple if injectors that leak back around the 6 second mark and that will also prevent starting, you often get away with one leaking at 6 seconds.

If any injector fails the above test that will be the problem, however they can pass the above and still be leaking back which then require testing while cranking, which is a bit more complicated, try the easy one first and see the result.

thanks guys.

my problem is on cold starting, once its starts its fine.

when i do manage to get it started emits abit of smoke but i assume thats where ive kept cranking it over.

once its starts and warms up a bit its fine.

my concern is as the winter is on its way that it may let me down, so trying to look after it and getting it sorted before it breaks down.

i have a 2002 TD4 auto.

thanks as always

gary