Cleaning injectors

[stevefh]

Hi all, I am using a syringe etc. to make a gizmo to blow cleaning fluid through the injectors. I want to make it before I take them off my esprit S4. I need to know the diameter of the rubber ring when fitted to the injectors, top and bottom, primary and secondary .Hope they are one size. I need it to be a tight fit in the open end of the syringe or source another rubber ring.Thanks for any help.

[Vulcan Grey]

The o-rings are 14mm.

I bought a cheap injector cleaning kit on ebay for $9 that snaps onto an injector. I also wired up a cable that clips onto a battery and uses a pushbutton and relay to activate the injector for short bursts.

I also actually found that transmission flush does a better job of cleaning out the injectors. Much better than injector cleaner. 

 

[sailorbob]

Despite the fuel rail and inlet manifold bores being different sizes the Lotus OE injector O ring is the same for both ends of the injector. The bore is fractionally smaller than 8 mm and the cross section appears to be 3.53 mm.

 

[stevefh]

Thanks for replies,I had seen the gizmo on eBay ,glad to know it’s a good fit ,as that’s why I didn’t just buy it in the first place. I am currently running Redex Advanced in the fuel to try to clean the complete system and will then clean the injectors separately. I used an auto stethoscope yesterday to listen to the easy to get at front 2 primary injectors and the rear secondary injector to see if I could hear their solenoids firing.They all sounded if they were.Surely the secondary doesn’t fire at idle.Could the sound be travelling from the tappet and this method not work.

[sailorbob]

On a stock S4 the secondary injectors are not used unless the engine speed is greater than 4800 rpm. It was probably noise from something else you could hear. If you use one of the diagnostic tools / programs it allows you to see the injector dutycycle and you will be able to see if the secondary injectors are in use or not.