IP noise, QA out of wack? Help!

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. Noise also continues if fuel shutoff solenoid is disconnected. Presumably this is the quantity adjuster.

Questions:

What should i look into to solve this issue? Could it be an issue with my swap wiring? What could potentially cause the qa to shutter?


Car runs flawlessly otherwise.

Thanks in advance for the help, it is greatly appreciated. Looking forward to hitting the road with this car!

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

Lots of things here, no easy explanation. This is clearly abnormal behavior.

My first initial guess (and that's honestly what it is) is your IP has a problem. BUT, I will say that where it actually originates from is a tough question.

My first stop would be to check the IP wiring connections and specifically the grounds with a meter. If I didn't find anything amiss there I would move on to the ECU.

Figure out what ECU you have (B4, Mk3, black box, silver box) and 1) find a substitute for testing or 2) find another operable TDI you can test yours in. It must be a like substitute for what you have now, which is unknown here atm.

If that doesn't reveal anything then I would turn to the IP and probably take it to a Bosch shop for diagnostic work or install a substitute on the car. I would avoid the second option here, it's a lot of work to setup just for testing unless you have a known good replacement.

And finally, my suspicion here is that this will end up being a wiring snafu. And I say that because it's a conversion and AFAIK we know nothing about the conversion or how it was done or who did the wiring work and to what extent it was done.

I know you said it was a CE2 integration but based on my own conversion in a 90 B3V that doesn't mean anything because there are still some significant differences that make this non-PNP. Unless those differences are well thought out and fully rationalized with the existing CE2 there could be problems.

Also, we don't know what harness was used in the conversion either and there are some minor differences between Mk3 and B4.

Steve

Steve,

Thank you for the great response.

As time allows, I am going back through the wiring to conduct voltage drop and resistance checks, I agree this is a great place to start, and honestly the most likely culprit. (K.I.S.S)

The harness / engine / trans / ecu are from a B4 Passat; cluster however is from a MK3, Vehicle is a 1992 Jetta. Complete swap including body harness. The few needed splices were performed using factory approved technique ( proper wire prep, solder, dual wall adhesive heat shrink) Irregardless, we are still dealing with wire, connectors, etc that spent 25 years in an harsh under hood environment. Making note, vehicle functioned without issue for roughly 2 years prior to this occurrence; not a fresh swap having issues.

I agree with the replace with known good part method of troubleshooting; quite effective if no known factory approved tests can be performed to verify functionality of a given component. Unfortunately I am at a disadvantage with not possessing known good spares, and a do not want to be chasing my tail around with unknown condition parts from the local u pull it, or spending hundreds on what amounts to diagnostic aids.

Ill have to scan through the service manuals for testing procedures, then off to local independents specializing in TDI engines and or Bosch pumps to enlist some help if we make it this far in the process. I have made it this far without access to VCDS, now may be the time to purchase!

Thanks for the insight!

P.S

Video of said issue:

https://youtu.be/BEHm5UNMW-o

Interesting... I think I can hear the buzzing with the car running.

The DFIS pump I have on my B4V makes that buzzing noise, but in 3 short bursts. It’ll stop on its own after 3 bursts, but my B4 and Jetta don’t make that noise.

-Todd

ToddA1, thanks for the info.

Had some time to sit down and methodically go through the majority of the engine / ecu harness with a fluke and a set of push pins: I checked out all the main chassis grounds first, then off to ecu ground, then sensor grounds, then off to power input to ecu.

Everything checked so far has been within acceptable range, voltage drops (with circuits under load) have been .1v or less, and resistance values close to 0. Next checks will concentrate on outputs / inputs from ecu to their respective locations.

Very interesting observation while conducting these tests: I just so happened to have my hand on the N75 valve while the car was displaying the condition... and to my surprise, the valve was pulsing on and off at the same frequency as the timing solenoid. To verify, i disconnected and probed the wiring with my test light, and sure enough it was pulsing.

So this latest observation has me leaning away from an IP failure of any kind and more to a wiring issue I have yet to find or an ecu fault.

When you mentioned the erratic IP operation I wondered if there wasn't some connection to the N75 since it basically opens and closes constantly in it's regulation of boost.

You might check for continuity at the IP with ECU pin 47, since that's the N75 connection at the ECU.

Also, make sure that the 2 pin connector above the 'orb of death' is brown and not black. The black 2 pin connector is for the charge air temp sensor, the brown is for the IP.

Not really sure what the consequences of connector mismatch would be but just a verification that the connectors are in the right place.

Steve