RE: [DML] Cleaning fuel injectors

["John Hervey" <john@xxxxxxxxxxxxxxxx>]

Andy, 
All the ideas are ok but cleaning injectors is only 1/3rd of the process.
Cleaning external looks good but doesn't do any good for running. Soaking
won't do anything inside the injector where it counts. They can be rusted
real bad on the out side and be wonderful on the inside.

#1. Check for pattern of 1/2 or better. If they squirt a stream then they
need to be cleaned several times to see if there is any improvement. 
Squirt is no good. Bad injector.
You lose or have no performance and mileage if they squirt and they don't
atomize the fuel. If you apply an unregulated pressure as suggested by some
then you may be able to force a pattern but under normal operating
conditions it may be a stream and they are no good. 

#3. Opening pressure of the injector. How are you going to see if all the
injectors are about the same opening pressure if you can't control the
pressure applied and have a way to read the applied pressure. Unstable idle
is also caused by injectors opening at different pressure. One or more
injectors can be squirting a stream and bleeding off pressure to others
because they are out of balance, so you have one or more cylinders running
rich and others maybe lean. Unbalanced idle.

#4. Now the last stage. Take the pressure off and see if they hold pressure
and for how long. Book say's they shouldn't drop below 1.7 bar after 10 min.
How do you do this with out the equipment. If they do drop to 1.7 bar then
how fast did they do that. 
Now if they bleed down here is part of the hot start problem. Where did the
fuel pressure and gas go and into what cylinders will it load up. I have had
a lot of injectors that have a good pattern but as soon as you take the
pressure / fluid off they drop like a rock. Gas goes into some of the
cylinders and none in others. Now you have a hot start and loading up
problem and uneven idle.

So if you have the equipment and want to get into the injector cleaning
business as I do then you will see what I mean by all of the above. 
But if you want to play around with it and not know how they are performing
then buy all the product suggested and see what shoe fits and have fun.

Just keep in mind that the performance of injectors can be shown in several
ways such as, hot start, smelling gas at start up, engine loading up at
idle, not level idling smooth or other ways can all be traced back to
injectors.

I have cleaned several hundred sets of mechanical injectors for Porsche,
Mercedes, Volvo, TVR and Delorean and they all work the same and have the
same problems. And yes fuel varnish builds up inside all of them over time.

John Hervey


 
   









Original Message-----
From: dmcnews@xxxxxxxxxxxxxxx [mailto:dmcnews@xxxxxxxxxxxxxxx] On Behalf Of
Cecil Longwisch
Sent: Wednesday, May 04, 2011 4:29 PM
To: dmcnews@xxxxxxxxxxxxxxx
Subject: Re: [DML] Cleaning fuel injectors

I have found using an ultrasonic cleaner with Berrymans works best. Put
water in the ultrasonic and the injectors in a glass continer with Berrymans
and put it then in the water.
Some of the good ultrasonics also heat.
I then blow the ijectors out with air and you can see it the pattern is good
or not.
I have also used one of the commercial cannister cleaners that hooks up to
air that you fill with a chemical of your choice , screw it onto the
injector and on to an air compessor and it forces the chemical through.
Using both of these procedures in tandem will pretty much restore most
injectors to new condition..




On Wed, May 4, 2011 at 11:30 AM, <Soma576@xxxxxxx> wrote:

>
>
>
> Hey all,
>
> I replaced my injectors about 7 years ago, but I think it might be time
for
> a cleaning. I have no problem removing the injectors, so what would be the
> best, safe way to clean them? Should I just put them in a tray, soak them
in
> Berryman's B12 overnight or what? The car has been regularly driven, and I
> always put Stabil in the tank for the winter, but over the last two years
I
> have a slightly rough hot idle. Sometimes it surges once, idles a little
> erratic for awhile, surges, idles erratic... other times it sounds pretty
> good, but not steady like I know it can. I know it will purr like a
kitten,
> because it did in the past, so I'm thinking I might have a dirty injector.
>
> Thanks,
> Andy
>
> [Non-text portions of this message have been removed]
>
> 
>


[Non-text portions of this message have been removed]



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