N108 advance solinoid Issues.

Hey guys.


Would any of you have an idea as to what may be causing my issue?

The (cold start injector) advance solinoid N108 is activating when it shouldn't. The vehicle has a bit of a rough idle, and won't rev past 3k rpm. I put a switch on the engine management fuse, I forget the number. When one takes out the fuse, or uses the switch to in essence turn it off. The engine is happy to rev up all the way, obviously no boost. Because it is going to a default map. As soon as one connects power back to the cercuit, the ecu is telling the advance solinoid to activate and cause rough running, with no boost, and will hardly accelerate.

All the other sensors on that circuit are good, I have switched them with another vehicles sensors, and the car will still run well. I have voltage tested the all of them too. They are all okay. I have gone through the entire wiring system to make sure there are no chafed wires, and cleaned up any that are bad. I just cannot for the life of me figure out what is going on.

I would really appreciate some advice or info if anyone knows anything about this.


Kind regards


Jason

Take it no one knows about this issue. Sad.

Thanks anyway.

These are the codes the vehicle is giving..

Saturday,08,December,2018,15:39:15:16731
VCDS Version: Release 18.9.0 (x64) Running on Windows 10 x64
www.Ross-Tech.com

Address 01: Engine Labels: Redir Fail!
Control Module Part Number: 038 906 012 L
Component and/or Version: 1,9l R4 EDC G100SG 2812
Software Coding: 00002
Work Shop Code: WSC 31414
VCID: 193986B783D8E98232-4B02
5 Faults Found:

17946 - Fuel Shutoff Solenoid (N109)
P1538 - 35-10 - Open or Short to Ground - Intermittent
17849 - EGR Valve (N18)
P1441 - 35-10 - Open Circuit or Short to Ground - Intermittent
18027 - Glow Plug Relay (J52)
P1619 - 35-10 - Open or Short to Ground - Intermittent
17957 - Boost Pressure Regulation Valve (N75)
P1549 - 35-10 - Open or Short to Ground - Intermittent
17660 - Commencement of Injection Valve (N108)
P1252 - 35-10 - Open or Short to Ground - Intermittent

Readiness: N/A

Did you read the fault codes after you after you took the fuse out? That could cause those fault codes. Leave the switch on and reset the fault codes and check if they reappear when the engine is running. When and how did the issue appear?

You will get a lot more responses on this forum if you put more information in the first post(engine code, mileage, etc).

Hi,
tried to dig up a bit on German websites:
Did you measure the resistance (10-20ohms) of the solenoid from the ECU connector (This will make sure you have a clean connection all the way)? You said you tried another N108? Here are some links for N108:

http://www.vwbuswiki.de/index.php/N108_Prüfen#Pr.C3.BCfen

http://www.vwbuswiki.de/index.php/N108_Prüfen

They are in German but you could use this translator.
http://itools.com/tool/google-translate-web-page-translator

This forum is Power Enhancements. You could try the mk4 forum.

Jason, have you checked fuse #34? I had to deal with the intermittent open short to ground on all of the same parts. I will guess you have a frayed wire in the loom somewhere causing the intermittent error, as I did. When fuse #34 goes the engine has no power and no boost. If the N75 does not have proper voltage, you will not get proper boost. I know, I thought my N75 was bad, but it wasn't and I ran around in circles for days until I figured out the fuse/intermittent error issue. When you look at the fuse block, it is likely you cannot tell the fuse is blown while the fuse is plugged in--at least I could not-- as I looked at it many times while still plugged in, it did not have the tell-tale black smudge. If I can be of any more help, PM me.
The 12 or so volts that are on all the solenoids, I believe also affects the voltage at the advance solenoid. Just as an idea out there would be to unplug the #3 injector with everything connected back and see what errors you get/how the engine runs. I also went through a on-off bad connection with the #3 injector, and had bad timing advance notices as well.

kimpe said:

Did you read the fault codes after you after you took the fuse out? That could cause those fault codes. Leave the switch on and reset the fault codes and check if they reappear when the engine is running. When and how did the issue appear?

You will get a lot more responses on this forum if you put more information in the first post(engine code, mileage, etc).

Click to expand...

no the fuse is plugged in, it does work, that is the fuse that the switch is on, so that the engine can rev. this was an engine swap from a petrol to a diesel.. so the problem has been around since then.. its the last thing to complete with the swap is getting this engine to run properly.. we have had some temporary success, when it has run properly for some short periods of time. but now we cant get it to run properly..

eddie_1 said:

Hi,
tried to dig up a bit on German websites:
Did you measure the resistance (10-20ohms) of the solenoid from the ECU connector (This will make sure you have a clean connection all the way)? You said you tried another N108? Here are some links for N108:
http://www.vwbuswiki.de/index.php/N108_Prüfen#Pr.C3.BCfen
http://www.vwbuswiki.de/index.php/N108_Prüfen
They are in German but you could use this translator.
http://itools.com/tool/google-translate-web-page-translator
This forum is Power Enhancements. You could try the mk4 forum.

Click to expand...

we have checked the wiring from the solenoid to the ecu, and the ecu is seeing the solenoid and activating it, when it shouldn't be activated.. all the wiring is good. We have been through it all thoroughly, so there should not be any wiring issues, fingers crossed.. Sorry, I have looked at all the other sensors involved, they all have 12 volts and work on another car too. I have not taken out the N108, because that would require removing the pump, and we don't have another solenoid to replace it with.


I will check out those links shortly..

Nevada_TDI said:

Jason, have you checked fuse #34? I had to deal with the intermittent open short to ground on all of the same parts. I will guess you have a frayed wire in the loom somewhere causing the intermittent error, as I did. When fuse #34 goes the engine has no power and no boost. If the N75 does not have proper voltage, you will not get proper boost. I know, I thought my N75 was bad, but it wasn't and I ran around in circles for days until I figured out the fuse/intermittent error issue. When you look at the fuse block, it is likely you cannot tell the fuse is blown while the fuse is plugged in--at least I could not-- as I looked at it many times while still plugged in, it did not have the tell-tale black smudge. If I can be of any more help, PM me.
The 12 or so volts that are on all the solenoids, I believe also affects the voltage at the advance solenoid. Just as an idea out there would be to unplug the #3 injector with everything connected back and see what errors you get/how the engine runs. I also went through a on-off bad connection with the #3 injector, and had bad timing advance notices as well.

Click to expand...

fuse 34 is good. It works it lets the engine run, using the sensors, but while plugged in the ecu is activated the advance solenoid, and causing rough running and limited boost. all the other sensors and solenoids have 12 volts. So unless the N108 is bad, I don't know what is the issue here..


I will try unplug injector 3 and see what happens with the codes, I have run it with it unplugged, but I cannot recall what happened. I will let you know what happens.