Boost control causing sync loss?
 

So after I got a new CAS in my car I started to work with closed loop boost control. The first time I started working with it I didn't have much luck, but then on my way home from work I was making good progress on getting everything set correctly. Once it stumbled like it hit a boost cut, but it was right at about 5 PSI which is strange since my cut is at 13.

That was on Aug 27th. I had a 3 day weekend this weekend so I waited until this weekend to get the closed loop settings to be completely correct for what I want. Well kinda long story short the car looses sync when the boost solenoid is working. Here is what I did to figure this out.

Can runs fine with boost control off and using the wastegate. I then had the car running and turned boost control back on. The car drove fine, but it wouldn't get above spring pressure. I then turned the car off and back on and while driving as soon as the solenoid would start to run to go above spring pressure the ECU would loose sync and the engine would die because of it. While cranking it would not sync. If I turn boost control back off the car will then run just fine. Any thoughts on why this is happening?

Also I have a switch which turnes on a relay to power the EBC solenoid. Is there an issue with having it wired this way? From what I remember if I have the ECB on in the software, but I have the solenoid turned off from power it would still run, but as soon as I turn the switch it would loose sync. I am going to try to verify this again tonight.

sounds like the way you wired it introduced a short.

I am guessing you are thinking a short in the wiring for the solenoid, or in the MS? It is a DIYPNP which is why I ask. I will look through all of the wiring to see if there is anything that might be shorting.

I might also power the solenoid directly off the battery or something to simplify my wiring to see if it goes away. It is just strange because a week ago it was all working fine.

why do you need a relay at all?

the solenoid shoudl get switched power (blue connector in engine bay)

and then the MS grounds it.

put a simple toggle switch on the ground signal for wastegate/high boost.

ANYTIME you use a relay around electronic equipment, you need to make sure you've installed a flyback diode. A relay has a coil. It works just like your ignition coil.

That said, agree with Brain. Why do you have a relay at all?

I totally forgot about the 12V blue connector in the engine bay. That makes a lot more sense than how I did it. I will redo the wiring when it isn't raining and see how it goes.

Thanks guys. I am getting used to all of this electrical stuff both here and with what I am doing at work. I know how to wire things up, but it might not be the best way. This was one of those cases.

So I changed the wiring so it was getting power from the blue fog light connector, and I had the switch on the ground wire going to the MS.

I haven't had much better luck. Now with the switch off the car would loose sync, but I think that it was because I was turning the solenoid off and isn't that a coil like in the relay? With the switch on but boost off in the MS it looked like things were good. With boost on in the MS I would run, but again it wouldn't actually rise the boost even though it should have power and the MS was calling for a duty cycle. It was around 53% and I know I need about 65% to hit ~12PSI.

Tomorrow I am going to disconnect the wire to the MS just to make sure that without the boost controller everything works well. Then I am going to bypass the switch so it is just 12V power->solenoid->MS. Hopefully making it as simple as I can will work. I mainly just wanted the switch so I could run 7psi most of the time and only run 12 when I really want to or I am autocrossing. For now I just want to get it to work, which is still strange because it worked a week ago.

Dont toggle the 12v side.

wire it like I said, that's how mines been installed since 2006.

You can put in a simple switch to easily enable/disable EBC on either the (+) or (-) sides. Mine is done that way (have a teenage driver in the house). BUT, just a simple switch is all you need, not a relay. Toggle switches have the best reliability. And switch position is best set prior to start, not as you are running.

Perhaps you can draw out what you've done or are attempting to do? Your descriptions are a bit confusing.

i wouldnt want to switch 12v. that makes sparks. sparks make bad things.

I'm actually wondering about the circuit within the DIYPNP. It should have a flyback diode to handle the solenoid. I wonder if it's blown.

Post your external circuitry and the solenoid you're using. We'll go from there.

Attached is how I had it wired last night. I completely took the relay out. I noticed how the car didn't like me flipping the switch while it was running. I won't do that again. I will do it while it is off.

As I mentioned tonight I am going to take the switch out of it and see how things run. I made a sheet with different scenarios of the boost controller having power or not, and if I have boost control turned on in the software or not. I will be taking notes for each one. I will post it up when I am done.

As usual if anyone has more thoughts I am open to them.

solenoid is the one from DIY. I was just thinking the same thing about the circuit in the MS. I am going to take a look at it tonight to see if anything looks blown from when I had the relay.

the way you have it now is the way it should be.


toggle it at will. a lot of times I like to oscillate my boost, just because im bored.

ok so I made some progress today.

I took one of the wires off the switch so no power from the solenoid would be going to the ECU. The car ran fine with the boost control turned on and turned off in the software.

I then connected the two ends of the wire where the switch was just to take the switch out of the equation. When I did this the car was off. I then turned the car on and then switched the boost control in the software on. The car dipped like it usually does when you burn something. The car then drove around fine, but it would not get above wastegate boost. I then turned the car off and back on. When I took off that time as soon as it started to go for a duty cycle sync was lost and the car turned off. It would not restart until I turned boost control off in the software. Even before I turned it off in the software, I disconnected the wire from the MS to the solenoid and it would still not sync.

To make things more interesting I then switched from closed loop to open loop. Car ran fine and made 12psi like I want with the duty I had set. I never had an issue. I then went back to closed loop and it would lose sync.

Any new ideas? I attached my tune for everyone to look at.

So this seems strange since closed loop was working 2 weeks ago. Should I just try to reload the firmware and put the tune back on it? Maybe some voltage spike from the relay erased some closed loop functionality? Just thinking out loud.

Couldn't hurt. What you've described really does not make sense.

So last night up updated Tunerstudio and the firmware to 3.2.4. I was on 3.0.3r. everything looks fine, but it will not sync to start. Looking at the composite log it is not getting any signal for the upper signal which is the 1 per revolution if I remember correctly. I am getting the lower signal just fine. I checked and the ignition settings are the same as per the 96-97 DIYPNP instructions.

Any thoughts?

From memory didnt MS burn out the coils on firmware update if you dont disconnect them?

The I did the update in my apartment using the 12V AC adapter. I am going to try firmware 3.2.1 to see if I get a different result. I will be doing it in the car though this time, so thanks for the reminder for that. I will disconnect them before I update it.

OK so as I mentioned with the 3.2.4 firmware the ECU was not seeing one of the cam signals for some reason. I then flashed the ECU to 3.2.1. It would sync and after checking all of the settings I go tit running again which was great.

But now, as soon as I connect the wiring for the solenoid is looses sync instantly. If it is running as soon as I connect the wires it looses sync, but as soon as I disconnect them again it will run again.

If I hook it up with the car off it will crank fine and sync, but as soon as it fires up it dies again. It keeps going back and forth while cranking it syncs but as soon as it fires up and stops cranking it does again.

I attached some logs in case someone has an idea of what is going on. I looked over the wiring and nothing is grounding to the chassis anywhere. Should I just try to reflash another firmware?

Here is another log of the car running. and me hooking up the wires.

If open loop runs fine, then it means the wiring should be good (uses the same wires). Does open loop still work OK?

Nope, It looses sync when the wires are hooked up in open loop, closed loop, and with it turned off.

OK. At least that makes sense.

You've definitely got a short somewhere.

Anyway, I would start at the ECU connector and depin the EBC wire (you can ohm it first, might tell you something -- things can be shorted without "looking" shorted). Let's see if it's inside our outside the ECU. From there, just use a building block approach and try to see exactly which step causes the sync loss. That should give a clear indication of the issue.

I've been saying that!

So if I am following you correctly I can de-pin the factory wire so it doesn't go to the MS and then see what it does?

I am guessing if I power up the BC with the blue plug but it is shoring somewhere then the car will still die since there is a short from the wiring to the chassis or something somewhere? I am not really that good at diagnosing electrical issues yet. It just seems strange that it worked before, but now it doesn't.

Sounds to me like this might be easier if I just bring the BC wire into the MS with the DB15 connector in the future. I could just easily unplug it to see if there is a short somewhere. I don't know why I went into the factory harness to run the BC.

Also what do you mean my ohm it first? How would checking the resistance help find a short? I am open to learn.

Surprised that your EBC has been spliced into the factory harness.

Splicing/slicing factory harness should be avoided if possible.

If you depin that wire, you "should" isolate whatever you've done outside the ECU from the ECU. If the ECU is OK, then the car should not die, and you know to focus outside. If the car dies, then the problem could be in the box or perhaps some other wire you've spliced.

Here's a question for you . . . what, EXACTLY, do you mean when you say "me hooking up the wires"? Which wires? Be precise.

~0 ohms means continuity. You can check for continuity to chassis ground or to positive. Neither should be present. If you prefer, you can use your diode check function and listen for a steady (not momentary) beep.

On the diagram of how I wired the solenoid I posted before, I had the switch on the wire between the solenoid and the MS. I took the switch out, and just hooked the two ends of the wire together. I took a short 2" piece of wire with a blade connector on each end so I could connect the two ends together, but I could still add the switch if needed.

The switch wasn't the highest quality toggle switch, so I figured I would take it out to remove one potential variable.

OK, so just to clarify:

(+)--------(solenoid)--------(blade connector)--------(DIYPNP EBC Input)

If the blade connector is together, then the DIYPNP loses sync. It does this no matter which selection for EBC you've made in software (either OFF, Open Loop or Closed Loop).

If the blade connector is apart, then the DIYPNP operates normally, again no matter which selection for EBC you've made in software.

That means that you've verified the wiring is OK at least until the blade connector on the DIYPNP side. So, next step is to investigate the rest of the wiring leading to the solenoid. Also, check the solenoid function. With the ignition switch ON (so there is +12VDC on the "blue" connector), if you tap the blade connector to a convenient screw head you should hear the solenoid click. The click should close your tubing to the wastegate actuator (verify by blowing through).

So last night I had a chance to look into this. I checked for a short from the side of the blade connector which runs to the solenoid. I checked on multiple grounds and other bolts and did not find a short to that end of the blade connector

I then checked on the other end of the connector which runs to the MS. Again using multiple grounds and bolts there was no short.

I checked between the different grounds and bolts I was using just to make sure that they would show continuity and they did.

I then checked the same as I did above with the ignition turned on and got the same results. I also checked the voltage and I was seeing 12.4V on the side to the solenoid and the other end to the MS had 0V between it and ground. The bade ends were not connected when I did this. So that looks good to me.

I then tapped blade from the solenoid to ground and you could hear the solenoid close.

I then connected the blade connectors so the ECB was wired up and the car started just fine. Unfortunately, I didn't have my laptop with me so I couldn't turn on open or closed loop to see if it was working. I might have a chance to try it tonight, but it might be Saturday before I get a chance to look into it more.

I will post up what happens when I have a chance.

have you ever thought about checking inside the DIYPNP?

I looked inside when I updated the firmware, but I didn't see anything that looked shorted or blown.

Now that it isn't loosing sync with the wiring hooked up, I will check to see if open and closed loop work. If it still acts up then I will go through the DIYPNP again with a lot closer attention to detail.

Zach

So today I finally got chance to mess with the car during lunch. With the wires hooked up the car would run, but I didn't get any increase in boost over the wastegate level. I am guessing that something is off before between where I connected the wires and the MS. I am thinking on just wiring it so instead of going through the factory harness I will use the DB15 connector.

Just had some more thoughts on it. I did check that the solenoid was working by grounding the end of the connector so you could hear it click.

I believe that after I updated the firmware that the Boost controller settings still had the input being PAO, but I need to check and make sure that was what I used. I am 99% sure that was correct.

Just to put an end to this I finally got everything fixed. I brought the boost control signal into the MS by the DB15 connector and things are working well. I am in the process of tuning closed loop BC. I am getting there. Just need to fix overshoot on the top end when the throttle is applied since the turbo spools so fast, but I am getting there.

I'm having very similar issues to what you had. Again with a diypnp.
Every time the solenoid activates the rpms drop to 0. You said wiring through the db15 solved you issues, is this correct? What was your boost input, PA0?

you have faulty wiring and youre introducing a short.