Test run E-ALH with no ECU.

turbocharged798 · Jun 17, 2019

So long story short, I have acquired another ALH engine for really cheap as a core. So far it looks like a decent run-able engine. So I got thinking about this and in theory, I would need to do is put +12 the IP shutoff, and a few volts to the Q/A. The advanced solenoid would be pinned at full advance(I think, or full retard) but that should not prevent it from starting. Then I should be able to vary engine speed by adjusting the pump voltage. I believe its 0-5V but not 100% sure.

Has anyone tried this?

eddieleephd · Jun 17, 2019

I haven't tried it, however, it sounds perfectly logical.
Use a potentiometer to control the voltage and supply a ground to the block and IP.
I would recommend a resistor, or light bulb to force the voltage to be maximum of 5V to be sure you don't turn it up too high.
Could mark, or set the potentiometer limit somehow, to prevent going to far.
Possibly use 4 AA ,or C batteries to limit it to 6V maximum and avoid crazy issues, that should be more than safe.
I'll be waiting you're statement that it worked perfectly

Sent from my Armor_2 using Tapatalk

[486] · Jun 21, 2019

just use brake cleaner in the intake
it ain't half the angry that ether is

jimbote · Jun 23, 2019

i've started one with 12v to the stop solenoid and knocking the QA toward the trans until it had no choice but to fuel... then hand throttled it with the ASV

turbocharged798 · Jun 23, 2019

jimbote said:
i've started one with 12v to the stop solenoid and knocking the QA toward the trans until it had no choice but to fuel... then hand throttled it with the ASV

So it does work, still unclear how the ECU moves the Q/A, seems like its a 0-5V signal but I am nervous of damaging the Q/A electrics.

[486] · Jun 23, 2019

turbocharged798 said:
So it does work, still unclear how the ECU moves the Q/A, seems like its a 0-5V signal but I am nervous of damaging the Q/A electrics.

it is 0-5v differential not referenced to ground

iirc there's 12v from the 109 relay going in and the ECU modulates the voltage across it
~~so it is a little more complicated than just tossing 5v across it, though tossing something like 8v across it should get it to run away nicely~~

going back to mechanical pump terminology for clarity's sake, remember that you are not working the governor lever, you're on the rack directly with no overspeed safeties

make sure you can rip the wires out of the shutoff solenoid and QA easily, and keep a racketball in hand while cranking to slap over the ASV in case, as flipping the lever in a panic is surprisingly hard.

ETA: looking at the diagrams, again, do not put 8v across it I am being dumb. 5v is 5v no matter what as there is no reference to ground it doesn't matter what the input is. The ECU just does it this way with 12v going in because then it doesn't need a big fat regulated 5v supply. Get you an old garbage computer and power it up, scotchlock your way into the orange wires off the power supply, they'll give you 3.3v which should give you 60% qa travel or whatever

turbocharged798 · Jun 28, 2019

[486] said:
it is 0-5v differential not referenced to ground

iirc there's 12v from the 109 relay going in and the ECU modulates the voltage across it
~~so it is a little more complicated than just tossing 5v across it, though tossing something like 8v across it should get it to run away nicely~~

going back to mechanical pump terminology for clarity's sake, remember that you are not working the governor lever, you're on the rack directly with no overspeed safeties

make sure you can rip the wires out of the shutoff solenoid and QA easily, and keep a racketball in hand while cranking to slap over the ASV in case, as flipping the lever in a panic is surprisingly hard.

ETA: looking at the diagrams, again, do not put 8v across it I am being dumb. 5v is 5v no matter what as there is no reference to ground it doesn't matter what the input is. The ECU just does it this way with 12v going in because then it doesn't need a big fat regulated 5v supply. Get you an old garbage computer and power it up, scotchlock your way into the orange wires off the power supply, they'll give you 3.3v which should give you 60% qa travel or whatever

Thanks for the info, I have an adjustable benchtop power supply I was planning on using. So I guess it does work but like you said,there will be absolutely no governor at all. Might just give it a shot and see what happens. I'll post it when I do.

[486] · Jun 28, 2019

turbocharged798 said:
Thanks for the info, I have an adjustable benchtop power supply I was planning on using. So I guess it does work but like you said,there will be absolutely no governor at all. Might just give it a shot and see what happens. I'll post it when I do.

start with something like 1.2v ish
they free rev pretty darn quick with no limiting maps interfering

or just look in vag-com on a running engine what "modulating piston displ voltage" or whatever it was labelled as is at idle to give you a good idea of where you should be

jimbote · Jun 30, 2019

turbocharged798 said:
So it does work, still unclear how the ECU moves the Q/A, seems like its a 0-5V signal but I am nervous of damaging the Q/A electrics.

it was smokey and would have easily run away without the "air throttle" but yes, it works ....not sure on using external voltage but the QA motor seems fairly robust

jimbote · Jun 30, 2019

turbocharged798 said:
Thanks for the info, I have an adjustable benchtop power supply I was planning on using. So I guess it does work but like you said,there will be absolutely no governor at all. Might just give it a shot and see what happens. I'll post it when I do.

maybe try a loose QA on the bench before a hot test ? record the various positions 0-5v

Alberta 7.3 · Jul 3, 2019

[486] said:
just use brake cleaner in the intake
it ain't half the angry that ether is

Don't try it with the chlorinated stuff. Burning chlorinated brake cleaner produces some toxic vapors.

WD-40 works well as an ether substitute also.

[486] · Jul 3, 2019

Alberta 7.3 said:
Don't try it with the chlorinated stuff. Burning chlorinated brake cleaner produces some toxic vapors.

WD-40 works well as an ether substitute also.

chlorinated brake cleaner don't burn
only an idiot would try using it as starting fluid, and not because a small percentage of what comes out the tailpipe will scar your lungs

chlorinated hydrocarbons decompose into nasties like phosgene when you get them hot
common knowledge in the refrigeration field

Alberta 7.3 · Jul 3, 2019

[486] said:
chlorinated brake cleaner don't burn
only an idiot would try using it as starting fluid, and not because a small percentage of what comes out the tailpipe will scar your lungs

chlorinated hydrocarbons decompose into nasties like phosgene when you get them hot
common knowledge in the refrigeration field

Exactly. Common knowledge for some people, but many people are unaware.
I've seen people use it for carb/intake cleaner, and GTFO of the area when the smoke cloud appears.

Mark6 · Jul 8, 2019

Not to hijack your thread, but

Have any of you hit the QA with ~4-5 VDC to test the QA actuation?
I have a buddy’s Snap On test probe that can provide a configurable DC voltage. Only issue is that it’s tied to chassis ground, but I tested all of the pins in the IP plug harness and none of them are tied to ground.
I just don’t want to whack my (presumably) good pump internals.
Any insight would be much appreciated.
I’m chasing a harness short or bad ECU. Just want to verify it’s not the QA.

Ramdiesel78 · Jul 16, 2019

I had an issue with the immobilizer not being deleted in the tune. I was able to make it run with the top off of the qa and moving the lever my hand. It was messy and smokey but it did run like that

Test run E-ALH with no ECU.

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