[Diy_efi] could i have multiple bad injectors? (UPDATE)

Fri Jan 24 02:20:14 GMT 2003

ok, as an update, i have rigged up an injector testing setup, where i have a 
pump with a feed line, in a bucket, with a gallon or two of gas. it feeds 
into a dsm rail, which is mounted to an old dsm head, and it houses the dsm 
injectors.

none of the 6 that i recently had on the car leaked, one of the remaining 2 
(if you remember i purchased two sets of four) did leak, it dribble out at a 
somewhat steady, quick pace. i have even hooked up a pump to the fuel 
pressure regulator and put about 85 to 90 pounds of fuel pressure on the 
injectors, but still no leak.

i am confused as to how the test conditions are any different than the 
original conditions ... the injectors are housed in a different rail and 
different head (as opposed to an intake manifold before) but none of those 
differences should effect a leaking pintel? i visually inspected the pintels 
and found none to appear bent or damaged.

if anyone has any thoughts, i'd love to hear them, as i am completely 
stumped as to why i can't duplicate? could the vibration of the running 
motor have something to do with it? wtf?

thanks

-j

>-----Original Message-----
From: diy_efi-bounces at diy-efi.org [mailto:diy_efi-bounces at diy-efi.org]On
>Behalf Of Toyota Supra
>Sent: Wednesday, January 22, 2003 11:17 AM
>To: diy_efi at diy-efi.org
>Subject: re: [Diy_efi] could i have multiple bad injectors?
>
>
>i haven't checked to see if they were stuck open due to some sort of grime,
>i might examine that with the pintel area, with a magnifying glass. they
>never sat in any sort of fluid, or in the car for a long period of time,
>just in storage after i removed them from the 2 vehicles that they came
>from.
>
>the history of the injectors, is that i have 8, 2 sets of 4, both coming
>out
>of running dsms about 6 to 7 months ago, that ran well with them, and that
>upgraded to 550's. the stock injectors are 450cc injectors, and make great
>secondaries, so i decided to use those. after 6 or 7 months, i have finally
>gotten around to modifying the intake manifold, making the fuel rail and
>additional fuel lines for everything to work, but now of course, the
>injectors are crapping out. i am going to try one new set of 6 as a last
>resort, if they still do the same thing, i don't know what i'll be able to
>do until i can find a smoking gun.
>
>thanks again
>
>-j
>
>
>
>
>
>
>
>
> >From: Mike <erazmus at iinet.net.au>
> >Reply-To: List for general do-it-yourself EFI talk <diy_efi at diy-efi.org>
> >To: List for general do-it-yourself EFI talk <diy_efi at diy-efi.org>
> >Subject: re: [Diy_efi] could i have multiple bad injectors?
> >Date: Wed, 22 Jan 2003 23:56:17
> >
> >IF they leak at all under those sorts of pressures then they
> >are damaged, who knows how <shrug>
> >
> >The pintles, should be regular and symmetrical...
> >
> >They might also be stuck or contaminated with fuel which had
> >a higher resin content from sitting in a tank for several
> >months, other than some sort of contamination or voltage
> >problem - I cant offer any more input, have htey been overheated
> >at some point ?
> >
> >Whats the history of the injectors ?
> >
> >rgds
> >
> >mike
> >
> >
> >
> >At 01:10 PM 21/1/2003 -0500, you wrote:
> > >mike,
> > >
> > >i haven't ever ran water or methanol or alcohol through the injectors.
> >the
> > >coils have not ever been engergized under my ownership as well, as i
> >haven't
> > >gotten to that stage yet. they are low impedeance, and the AIC 3 is
> >designed
> > >to control either after setting which type you have, but again, i
>haven't
> > >ever had it plugged in as of yet, so the coils could not have been over
> > >driven either, but a good suggestion none the less.
> > >it has absolutely no electrical connection, very good assumption, and
>the
> > >rail pressure is 37 (with no vacuum signal) verified by my electrical
> >fuel
> > >pressure gauge and my mechanical one.
> > >i will examine them tonight with a magnifying glass to see if i can
> >visually
> > >see damage, one other thing to note is that they don't leak
>immediately,
> >it
> > >takes a couple of seconds for the fuel to push past the pintel? is that
> > >consistent with a bent or damaged pintel?
> > >
> > >thanks for the info mike
> > >
> > >-j
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >>From: Mike <erazmus at iinet.net.au>
> > >>Reply-To: List for general do-it-yourself EFI talk
><diy_efi at diy-efi.org>
> > >>To: List for general do-it-yourself EFI talk <diy_efi at diy-efi.org>
> > >>Subject: > >>Date: Tue, 21 Jan 2003 23:50:33
> > >>
> > >>A good magnifying glass helps to look at the pintle, though
> > >>you have to pull off the plastic covers (well mine had some),
> > >>also have you run any other fuel through them ?
> > >>
> > >>I hear rumours that running water for even a short time will
> > >>produce enough corrosion so the metal to metal seal of the injector
> > >>is compromised. Also if you have run alcohol or methanol in
> > >>a petrol only injector then there could be some corrosion after
> > >>a while, also is your fuel really clean and free of particles,
> > >>these might also cause the pintle to not close properly,
> > >>
> > >>Other thing is - have you over-driven the coils, say put low
> > >>impedance injectors on and left driven hard for too long,
> > >>ie. Not pulsed - this can overheat the coil and the spring
> > >>and effectively 'operation outside specs'...
> > >>
> > >>Also I take it you are testing on your system with absolutely
> > >>no electrical connection, not just assumption its not driven,
> > >>ie. Connector actually removed, so if you see a dribble from
> > >>the pintle when pressurised, dont bother with them, toss em
> > >>out...
> > >>
> > >>Then if your rail pressure is really OK and not out by say a
> > >>factor of 10 (dont laugh - I've seen that one on a pressbrake!),
> > >>then it does indicate injectors are stuffed - if you got them
> > >>new then take em back on warranty unless you've run an ionic
> > >>fuel through them for any length of time - or water :(
> > >>
> > >>rgds
> > >>
> > >>mike
> > >>
> > >>
> > >>
> > >>At 10:12 AM 21/1/2003 -0500, you wrote:
> > >> >thank you for the replies, just to clarify
> > >> >
> > >> >the injectors are not receiving any sort of electrical signal, once
> >they
> > >> >prove to function properly, they will be hooked up to an AIC 3, but
> >right
> > >> >now, it is nothing.
> > >> >since the injector is the only path for the fuel to get from the
>rail
> >to
> > >>the
> > >> >manifold, they have to be the source of leakage, but i am not sure
>as
> >to
> > >> >why. mike has mentioned that they could have had the pintel bent,
> >which
> > >>at
> > >> >least is feasible, but i was careful to set them down with the ends
>up
> >in
> > >> >the air, and not resting on anything. i will probably try a test
>with
> >a
> > >> >bucket full of fuel and a pump to see if i can simulate conditions.
> > >> >
> > >> >the fuel pressure is 35 or 37 pounds for base, they have never seen
> >boost
> > >> >and are leaking at the base pressure, and they have not received an
> > >> >electrical signal as of yet.
> > >> >
> > >> >is there a way to to examine the injectors to see if the pintel is
> > >> >physically damaged, does it bend or kink open and will i be able to
> > >>visually
> > >> >inspect and see that?
> > >> >
> > >> >thanks again for the replies
> > >> >
> > >> >-j
> > >> >
> > >> >
> > >> >
> > >> >
> > >> >
> > >> >

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