[Diy_efi] could i have multiple bad injectors?

Wed Jan 22 15:35:47 GMT 2003

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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