RE: [DML] Cleaning fuel injectors

["John Hervey" <john@xxxxxxxxxxxxxxxx>]

I have been cleaning mechanical injectors for 10 years and as you can see
there is more to it than soaking and external cleaning.
John
( delorean answer man )
Nothing to join help.
7/12 9am till 9pm


-----Original Message-----
From: dmcnews@xxxxxxxxxxxxxxx [mailto:dmcnews@xxxxxxxxxxxxxxx] On Behalf Of
soma576
Sent: Thursday, May 05, 2011 8:49 PM
To: dmcnews@xxxxxxxxxxxxxxx
Subject: Re: [DML] Cleaning fuel injectors

Hi John, 

Really good points you brought up.  I will pull out all six injectors and
test at the same time into glass jars to see if I even have a problem with
them.  If I do, I will probably just send them to you for cleaning.

Andy



--- In dmcnews@xxxxxxxxxxxxxxx, "John Hervey" <john@...> wrote:
>
> 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@...> 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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