[Diy_efi] could i have multiple bad injectors?

Wed Jan 22 19:06:06 GMT 2003

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: re: [Diy_efi] could i have multiple bad injectors?
> >>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
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >=====================================================================
> >> >
> >> >Some ECUs will sort of crack open the injectors if the driver
> >> >circuit loses a signal ground. Check your grounding all over
> >> >(engine to chassis, chassis to powertrain, chassis to ECU, and
> >> >while you're at it clean up the straps to shiny and coat with
> >> >thick grease after assembly). Let us know how you get on.
> >> >
> >> >Cheers,
> >> >Rod
> >> >
> >> >
> >> >=====================================================================
> >> >
> >> >
> >> >I changed all my bosch injectors about a year ago and during
> >> >the process I noticed its very easy to bump/graze the small
> >> >pintle at the end of the injector!
> >> >
> >> >So if there is fuel pressure and no signal and they leak then its
> >> >logical to conclude they have received physical damage *or* your
> >> >fuel pressure is way too high for the injectors...
> >> >
> >> >rgds
> >> >
> >> >mike
> >> >
> >> >
> >> >=====================================================================
> >> >
> >> >
> >> >
> >> >Those should actually be Nippon Denso 450cc injectors and they are 
>very
> >> >reliable.  I really doubt it is bad injectors.  You just changed to
> >>staged
> >> >injection, so I would look into that.  It sounds like they are being
> >>fired
> >> >when they shouldn't be.  Usually when those injectors go bad they will
> >>not
> >> >fire at all.  I have had one go bad in 9 years having Talons.
> >> >
> >> >JET
> >> >92 Talon AWD
> >> >
> >> >
> >> >=====================================================================
> >> >
> >> >
> >> >----- Original Message -----
> >> >From: "Toyota Supra" <turbosupramk3 at hotmail.com>
> >> >To: <diy_efi at diy-efi.org>
> >> >Sent: Monday, January 20, 2003 9:29 PM
> >> >Subject: [Diy_efi] could i have multiple bad injectors?
> >> >
> >> >
> >> >>as a background, i have just installed staged injection on my 6
> >>cylinder,
> >> >as
> >> >>it was being tried out, the smell of fuel was prevelant without the 
>car
> >> >>running. after searching for leaks, i could see fuel leaking in 
>between
> >> >the
> >> >>upper and lower intake manifolds, because it was leaking past the
> >>injector
> >> >>and into the manifold, then puddling and seeping past the gasket
> >> >>
> >> >>... now, how could i have more than 1 injector do this? the odds are
> >> >pretty
> >> >>astronomical i would think? the secondaries are bosch style 440cc
> >> >injectors
> >> >>out of a talon (1 and a half sets) and the car ran great before 
>removing
> >> >the
> >> >>very injectors i am trying to use, and upgrading to larger ones.
> >> >>
> >> >>so to summarize, i have 2 or 3 failing eclipse/talon/laser injectors,
> >>base
> >> >>pressure is only at 37 pounds, and there is no electrical signal 
>going
> >>to
> >> >>the injectors to open them. i can't see the injectors having a 
>normally
> >> >open
> >> >>coil, or everytime the car ignition was on, and the fuel system was
> >> >primed,
> >> >>it would flood before the ecu started to oscillate the injectors and
> >> >>signalling them to close
> >> >>
> >> >>sorry for the long post, i just can't figure out what is going on 
>here,
> >> >any
> >> >>and all info or theories would be appreciated. thanks
> >> >>
> >> >>-j
> >> >>
> >> >>
> >> >
> >> >
> >> >
> >> >
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> >>
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