NefMoto

Technical => Diagnostics => Topic started by: fknbzn on December 08, 2023, 01:29:45 PM



Title: Questioning if I have voltage at n75
Post by: fknbzn on December 08, 2023, 01:29:45 PM
Working on a stage 3 tune for 1.8t AWN w/ GT3071r internal wastegate at 7.5psi, forged BOV and having problems meeting requested boost.  Boost is holding at WG pressure with some boost creep at the end, I think.  Replaced n75 valve and have no change in boost.
 
I'm starting to think that I'm not getting voltage to n75.  What do ya'll think? 

Is there any better way to check other than meter or test light at connection?  Isn't there a way to cycle all switches in VagCom?

ecuxplot  below.
(https://imgur.com/a/U0NjdLC)
https://imgur.com/gallery/U0NjdLC
(https://i.imgur.com/avTfDhW_d.jpg?maxwidth=520&shape=thumb&fidelity=high)


Title: Re: Questioning if I have voltage at n75
Post by: fknbzn on December 08, 2023, 01:47:06 PM
csv file


Title: Re: Questioning if I have voltage at n75
Post by: nyet on December 08, 2023, 02:37:25 PM
post the actual log


Title: Re: Questioning if I have voltage at n75
Post by: nyet on December 08, 2023, 02:38:30 PM
really odd choice of axis's (axes?). you should pick two that make more sense. put values that have simliar ranges in the same axis.


Title: .
Post by: fknbzn on December 08, 2023, 02:55:20 PM
.


Title: Re: Questioning if I have voltage at n75
Post by: fknbzn on December 08, 2023, 02:57:02 PM
really odd choice of axis's (axes?). you should pick two that make more sense. put values that have simliar ranges in the same axis.

Thanks for the tip.


Title: .
Post by: fknbzn on December 08, 2023, 03:18:39 PM
.


Title: Re: Questioning if I have voltage at n75
Post by: fknbzn on December 08, 2023, 03:23:52 PM
.


Title: .
Post by: fknbzn on December 08, 2023, 05:26:52 PM
.


Title: Re: Questioning if I have voltage at n75
Post by: fknbzn on December 14, 2023, 08:21:38 PM
Took another log.  Lets see if it will let me post it.


Title: Re: Questioning if I have voltage at n75
Post by: fknbrkn on December 14, 2023, 11:02:39 PM
Check bov vac line, n75 for proper installation (wg line at the opposite side of the long pipe of n75)
Try to run without wg line connected


Title: Re: Questioning if I have voltage at n75
Post by: fknbzn on December 14, 2023, 11:33:32 PM
Check bov vac line, n75 for proper installation (wg line at the opposite side of the long pipe of n75)
Try to run without wg line connected

Waste gate is plumbed correctly.  I disconnect BOV, same problem.  When cycled with VagCom n75 and n249 both appear to be working.  I'm gonna do another boost leak check tomorr, again!w.  I've been checking from the MAF and will check from turbo to make sure BOV is holding.  Throttle valve is open, no timing pull and WG dwell looks correct.  I'm leaning toward faulty N75,  even though it is new cheap eBay replacement. New N75 feels week when cycling, but I do not have anything to compare to and it is a small solenoid so that may be normal.  I was reluctant to run without WG hose attached because I didn't want it to run away.  I guess ME7.5 would open BOV and close  throttle in that case. I'll disconnect WG and log tomorrow. I think it is definitely a hardware problem.

Thanks for the help!


Title: Re: Questioning if I have voltage at n75
Post by: aef on December 15, 2023, 12:22:02 AM
looks like basepressure to me


Title: Re: Questioning if I have voltage at n75
Post by: justinvw2646 on December 15, 2023, 06:23:50 PM
If you are running the forge recirculation valve make sure the port that sees boost pressure is the one on the side (you can see the side of the piston when you look into the port) and then hook the other port to the TIP. The instructions say the opposite, but I had one of those things and boost would push the piston up and open the valve even when the spring was preloaded at max. I no longer run the forge unit. Stock replacement living life at 2 bar fwiw solved a bunch of boost control crap for me.


Title: Re: Questioning if I have voltage at n75
Post by: fknbzn on December 15, 2023, 07:37:57 PM
looks like basepressure to me
I agree.  Did some testing today.  Old N75 not activating, even though it ohms out correctly.  New N75 leaking to bypass when activated or not.  Working on getting another new one.  Did a boost leak check, BOV is holding and I found a boost leak under intake.  So those seem to be my problem.....
If you are running the forge recirculation valve make sure the port that sees boost pressure is the one on the side (you can see the side of the piston when you look into the port) and then hook the other port to the TIP. The instructions say the opposite, but I had one of those things and boost would push the piston up and open the valve even when the spring was preloaded at max. I no longer run the forge unit. Stock replacement living life at 2 bar fwiw solved a bunch of boost control crap for me.
That's kinda funny because people want to install OE BOV in reverse.  BOV is holding boost. Also it came with 3 springs.  I have the medium spring in for now.  I'm gonna keep it the correct way for now, plus I have a stronger spring if boost blows it open once I crank it up.  Thanks for the tip.