injection sensor from an AAZ pump used for a revcounter pickup????

[regcheeseman]

As part of my VNT project I'm looking for an engine speed signal, my AAZ pump had a sensor in the centre timing port on the pump head, I'm guesssing this was a basic pressure switch and would give me a 2 pulse per rev signal? The same as required by a petrol revcounter....

Anyone tried or tested this sensor?

[Vincent Waldon]

Yup, according to the Bosch yellow jacket it will deliver one fairly-clean 5V pulse per injection.... two per rev... exactly the same as a gasser ignition system.

Ergo, should be able to drive a gasser tach... if not directly then within a transistor/resistor/capacitor of signal conditioning.

Downside, for general usage, is that the sensor is pretty rare and probably pretty expensive. 

[wolf_walker]

That styer 6 in the bmw's and lincolns had em too, they are deff expensive new, but available.
I had the same thought, if I ever happen to see one in a junkyard I'll snag it.

Still seems like someone electrically inclined ought to be able to use a knock sensor or
some sort of piezoelectric setup to get such info, **cheaply**
I'd really like to be able to use a timing light on one of these things.

[Vincent Waldon]

Meh.... working on that exact thingie... cheapo junkyard knock sensor timing light adapter... too many projects.  Could easily drive a tach as well, although it would need a PLL to double the freq.

My darn day job keeps getting in the way of my night job.  ;-)

[wolf_walker]

You'd be even more of a diesel-Hero if you could pull it off, especially with that generic Bosch knock sensor there are billions of in the world.

[markb]

I had one of these later pumps with the electronic advance and sensor in the head.

I was under the same impression as you and came up with a system to control the advance using that sensor. Unfortunately when I hooked it all up it didn't work. I then checked teh output of the sensor and it was dead

You can get these sensors from bosch (quite hard to find someone that knows what you are talking about though) but they are about £170 from memory, therefore I scrapped the project.

[Vincent Waldon]

with that generic Bosch knock sensor there are billions of in the world.

Yup.  Got'er working actually but a bit too flaky on the triggering for general usage...so needs a bit more tweaking for reliability before it's ready for prime-time.

One of my TDIs just blew up the turbo seals so I'm distracted yet again.

[55eta]

i could be wrong but dont they use them on 1z tdi s?

[burn_your_money]

Mine doesn't have one. TDIs use the 3rd injector instead.

[regcheeseman]

Downside, for general usage, is that the sensor is pretty rare and probably pretty expensive.

Must have binned 3 or 4 in the last 12 months... definitely have 2 kicking round the garage.

Yup, according to the Bosch yellow jacket it will deliver one fairly-clean 5V pulse per injection.... two per rev... exactly the same as a gasser ignition system.

Really? The ones I have seem to be basic pressure switches, all are fed with a 12v signal - no 5v anywhere on a uk AAZ system unless you have one of the really late ones

[markb]

I've just dug out my yellow jacket and as you can see, they state 5V signal:


I have no reason to doubt the use of 5V for a sensor like this as it will be driven directly from the control unit. However, I havn't been able to look over a car running these pumps (only present on very late mk3s) to actually hook up a DMM or scope (I would dearly love to though, so if you know of one  ) as the control unit was already missing from the car when I got the engine/pump etc.

I had a look for the part number for the sensor too, but I can't find the piece of paper I wrote it on at the moment.

Mark.

[Vincent Waldon]

Yup, that's the exact page from the Yellow Jacket.

Fed with 12V but sends out a clean TTL-level 5V pulse for the ECU to process.

[truckinwagen]

so would one of these put out a signal that could be picked up by say, a four cylinder gasser tachometer without modification?

I am looking for ways to drive the tach I have(from an 80's bayliner)
I was going to use a hall sender and magnets on the crank pulley, but this would be much less prone to breaking off from vibration/kicked up stones

I am sure someone has a few lying around in their pile of parts(wanna sell me one for cheap? )

[regcheeseman]

Mark B - Vincent,

Still believe we are talking about two different sensors here...I'm talking about the non-ecu AAZ

What's the 'yellow jacket' is it available online?

how many wires on your sensor and does it have a part number - I'll check mine this evening...

so would one of these put out a signal that could be picked up by say, a four cylinder gasser tachometer without modification?

well - in theory yes but it would need signal conditioning,

I don't really care what the output is as long as it's a pulse, in fact 5v would be preferable as it'll be plugged into a PIC with will decode the signal and drive another pic containing a 3D VNT control map and also the standard gasser tacho.

[Vincent Waldon]

I'm talking about the non-ecu AAZ

What's the 'yellow jacket' is it available online?

Hmmm... could be.  The sensor I'm thinking of is the "start of injection" sensor that screws into the IP where you'd normally insert the timing gauge... measures and then signals pressure as the plunger starts its injection cycle.

Bosch "Yellow Jackets" are a series of small books Bosch puts out on various automotive subjects... including various diesel components.  Available at most major book outlets that would also carry the Bentley service manuals.