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Author Topic: How does the glow plug control know what the rpms are for injector start valve?  (Read 3332 times)

October 13, 2016, 10:29:45 pm

R.E.wing_fc3s

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 Im transplanting an aaz(not sure which code) into a vanagon. It had a poorly installed aaz without the lda pump which the owner failed to check the oil often enough resulting in engine failure. We sourced a most most likely canadian aaz. Im trying to understand how the glow plug control module knows what the rpms are to then control the injection start positioner valve. It seems most engines and pumps that have this valve also have a couple sensors that this pump does not have. This pump only had the egr switch(deleted)  the fuel shutoff switch and the injection start positioner.

The harness from the pump to the main round connector is unchanged. on the chassis side it is cut.

ive read that voltage to this valve is cut above 2800rpm.

ive also read the full throttle basically cancels the effect of the valve.

ive read that the valve serves to retard timing. doesn't this counteract the manual cold start cable?

the reason i want the valve to work is because energized it makes the car run smoother at cold idle and seems to help the engine run smoother when cold. 

i dont have the glow plug control module yet to control the injector start positioner valve because i want to understand how the module knows when to switch the valve when theres no apparent rpm signal to the module with this pump.

it may just be easier to use a time delay relay run off the original vanagon glow plug relay to activate the injector valve.



Reply #1November 17, 2016, 04:48:13 pm

RunninWild

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if you are talking about the solenoid on the side of the pump, I believe its called the timing advance solenoid, just wire it into the fuel cutoff solenoid. like you said it runs better being powered the entire time. From what I understand I think it allows the pump to have somewhat dynamic injection timing, I'm not sure what system is being used to determine when and when not to give it power but I think the only reason it exists is for emissions. Maybe it gets its signal from the coolant sensors in the rad like the glow plug circuit?

Reply #2November 17, 2016, 05:05:00 pm

vanbcguy

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It's purely for emissions. It disables advance which reduces NOx but increases fuel consumption and EGTs. The general guideline is to ensure the dynamic advance is operating normally by giving it 12v all the time.

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Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

 

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