Injection pump electrical noise?

Orangejulius

Member
Joined
May 29, 2018
Location
Pittsburgh PA
TDI
Tdi mkii coupe
Awesome wealth of information here! Working to get my 91 jetta tdi swap on the road and hoping to learn a little from the forum.

Specifications:

AUH 1.9l TDI full CE2 swap into a CE2 MKII chassis

Observation:

Place key into run position, (not starting vehicle) after a 2sec delay, the IP will begin to pulse / click / tap loudly in a continuous cycle at roughly 1k clicks per min. Sounds like an electric solenoid valve rapidly cycling within the pump. This is no longer heard when the engine is running (could be still occurring, i just cant hear it due to engine noise) Noise will discontinue if key is turned off, or injection pump is electrically disconnected.

Questions:

Is this a normal occurrence?

If this is not normal, what should i look into to solve this issue? Could it be an issue with my swap wiring?

If this is normal, should i be concerned about damaging the pump if the car sits for an extended period in the run position without being started?

Car runs flawlessly otherwise.

Thanks in advance!
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
I've never heard it on either the ALH or AHU.

What I do hear is the the QA arm make a sweep and return to a lower setting and after several seconds the fuel solenoid shuts off.

Try disconnecting the fuel solenoid to see if that's what's making the noise. If that isn't it only the QA remains as the source.
 

Orangejulius

Member
Joined
May 29, 2018
Location
Pittsburgh PA
TDI
Tdi mkii coupe
KLXD,

Thank you for the reply. I disconnected wire from the fuel shutoff solenoid; the sound is still present. As you have stated, that only leaves the Quantity Adjuster as the cause.

Assuming now this is not a normal occurrence, what would cause the QA to pulsate?

Thanks for the help so far
 

Orangejulius

Member
Joined
May 29, 2018
Location
Pittsburgh PA
TDI
Tdi mkii coupe
Bump for more info:

I have isolated the noise to the timing solenoid in the injection pump; this is 100% the source of the noise. What type of output should the ecu provide this solenoid? Is is pulsed, or constant current under normal operation? My DMM is not quick enough per say to accurately detect the pulsation. I am trying to determine if it’s the ecu itself commanding the timing solenoid to pulse, or is it pulsing because the solenoid itself or something inside the pump is malfunctioning. Any thoughts on this or a good next step would be awesome. Thanks
 

Nutsnbolts

Vendor , w/Business number
Joined
Nov 1, 2001
Location
Weare, NH
TDI
2000 Jetta, Silver Arrow
I would try a test light on the wire to the solenoid to see if it's pulsing. Something is amiss, but I don't believe it's in the pump, because the solenoid would act once on a signal, not repeatedly unless the signal was repeated.

-Rich
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
You wondered whether it continues while the engine is running. I'd say no since you don't mention a bad idle which the QA controls.

You sure you've got it wired correctly?

My understanding is that while running the QA signal is pulse width modulated.

Do you have VCDS?
 

Orangejulius

Member
Joined
May 29, 2018
Location
Pittsburgh PA
TDI
Tdi mkii coupe
Thanks for the advice!

Rich, I ditched the dvom and dig out the old test light, and it does appear to pulse at the same duration as the solenoid. It is such a quick pulse, my dvom did not pick up the fluctuation but the light did. Good tip. So this effectively rules out the pump itself and put the focus on an electrical (wiring) issue / ecu.

Klxd, the swap was done roughly 2 years ago and this is the first the issue has presented itself. I am very confident that the car is wired correctly; ce2 tdi, into another ce2 car... complete harness swapped uncut. Idle is perfect.

Unfortunately I do not have access to vcds.
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
Oops. I forgot about the timing solenoid.

It too is pulse width modulated during operation.
 

Orangejulius

Member
Joined
May 29, 2018
Location
Pittsburgh PA
TDI
Tdi mkii coupe
From what I gather, this is correct. I am assuming this solenoid is pulsed adjusting fuel pressure continually as the engine is running. I have yet to find any information as to what conditions must be met in order for a signal to be sent to the timing solenoid. I wold presume the ecu is looking for an indication that the engine is running before it would send signal under normal operating conditions? ... and for whatever reason that condition is being met while my engine is not in motion. Crank position sensor? However I have never seen one fail reporting a signal?

Thanks
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
It controls pressure to a piston that runs transverse beneath the pump body that adjusts timing.

I'm not sure if it's the crank sensor or the #3 injector needle lift sensor that tell the ECU the engine is running but I think you're correct.

I assume the check engine and glow plugs lights are not lit since you didn't mention them.
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
Stabbing in the interweb darkness here, but shouldn't the pump only activate when in start position? Could it be as simple as the ignition switch?
 

Orangejulius

Member
Joined
May 29, 2018
Location
Pittsburgh PA
TDI
Tdi mkii coupe
Bobnoh, been doing a little research and not coming up with any info... this sounds plausible. I know most DBW vehicles energize the throttle body in the acc position;( you can hear the throttle movement, usually a single click) I am unsure if the IP operates in the same fashion.

Anyone with a correctly operating ahu / 1z and some free time: Can you cycle the key to the acc position and note any noises from the IP?

Thanks!

Continuing to go through the harness, conducting voltage drops looking for issues...
 

burn_your_money

Veteran Member
Joined
Oct 16, 2012
Location
Missouri
TDI
99 Beetle, 96 B4V, 05 Passat wagon
Do you have VCDS? You can see the commanded duty cycle of the solenoid. If it's matching your test light then you at least know the ECU is telling it to do that. If it's not, then you have wiring issues.


Also check it when running to see if it's doing the same thing or not.
 

Orangejulius

Member
Joined
May 29, 2018
Location
Pittsburgh PA
TDI
Tdi mkii coupe
Thanks for the advice! Good call on both accounts. Unfortunately I do not have vcds. I think now is a good time to place an order with Ross tech; I think this justifies the purchase along with the fact there are 3 other vehicles at the house I can utilize the system on.
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
Bobnoh, been doing a little research and not coming up with any info... this sounds plausible. I know most DBW vehicles energize the throttle body in the acc position;( you can hear the throttle movement, usually a single click) I am unsure if the IP operates in the same fashion.

Anyone with a correctly operating ahu / 1z and some free time: Can you cycle the key to the acc position and note any noises from the IP?

Thanks!

Continuing to go through the harness, conducting voltage drops looking for issues...
My '98 makes some relay noises in the dash in the ACC position. Nothing from the IP until the run position.

Would be nice if you would keep only one thread going on this.
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
Don't do that, there's good info here. Just pick one thread and ask folks to respond in that one.
 
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