Boost solenoid - how to test

Nebburns · 7th April 2014, 20:08

Hi all,

Just doing some fault find this evening after I have the typical boost 'jerk' on my 1.8t.

Can I just do a sanity check to ensure that I understand the operation of the boost solenoid. If I apply a 12v source across the pins and I can hear the solenoid energise (click) and de-energise (click) can I assume that the solenoid is in actual fact fully functional and not faulty?

Regards

speeddevil68 · 7th April 2014, 20:59

Are you able to read the boost pressure? (OBD, T4, IPK??)

Nebburns · 8th April 2014, 04:58

Quote:

Originally Posted by speeddevil68

Are you able to read the boost pressure? (OBD, T4, IPK??)

Hi,

I have an OBD reader, I assume you mean to look at MAP to see what the peak reading is? Or is there another way to determine boost pressure via the OBD?

Thanks

Nebburns · 10th April 2014, 11:22

Anyone else?!

Thanks

MG Tom · 10th April 2014, 12:01

To start with gap your plugs to 0.65mm and report back.

Nebburns · 10th April 2014, 16:06

Quote:

Originally Posted by MG Tom

To start with gap your plugs to 0.65mm and report back.

Hi Tom,

I think I know you? You probably remember my brother Sam (blue MG ZS and me with the Honda Civic?)

How's things??

I've just completed a full top end rebuild (with turbo) and was hoping this issue would be resolved as part of all that.

Anyhow, I did gap the new plugs to 0.8mm so I'll give the .65mm a go tonight and let you know.

Thanks.

Ben.

MG Tom · 10th April 2014, 19:46

Hi Ben

It's a small world

I have a spare solenoid in the shed which I'll pop in the post if you need it.

I tried 0.8mm to start with, but .65mm was a very definite improvement! Some have even gone to 0.5mm.

We really need uprated coil packs for the turbo motors, I think its as simply as boost blowing the spark out!

Quote:

Originally Posted by Nebburns

Hi Tom,

I think I know you? You probably remember my brother Sam (blue MG ZS and me with the Honda Civic?)

How's things??

I've just completed a full top end rebuild (with turbo) and was hoping this issue would be resolved as part of all that.

Anyhow, I did gap the new plugs to 0.8mm so I'll give the .65mm a go tonight and let you know.

Thanks.

Ben.

arodriguez · 10th April 2014, 20:51

Quote:

Originally Posted by MG Tom

To start with gap your plugs to 0.65mm and report back.

Yep agree totally. Had the same problem and wasted £28 on a new boost solenoid. The problem was the plug gap - set mine to 0.6mm and hey presto - Revving sweet all the way round.

The garage had originally set them to 0.8mm on my instructions but it misfired badly at 2800rpm onwards on full throttle. I never imagined 0.2mm would make any difference

but to my astonishment it totally fixed a long standing issue. That's with new coil packs and plugs too.

We should really make this boost misfire thing a sticky as it took me months to find this cure!!

Nebburns · 14th April 2014, 11:27

Hello again,

Sorry it took me slightly longer to come back however - ITS FIXED!

Plug gap set to 0.65 and no more misfires!

Thank you both for your help!

Ben.

MG Tom · 14th April 2014, 11:53

Result! I was sure that'd sort it.

7th April 2014, 20:08	#1
Nebburns Regular poster MG ZT-T Join Date: Dec 2013 Location: Midlands Posts: 30 Thanks: 3 Thanked 2 Times in 2 Posts	Boost solenoid - how to test Hi all, Just doing some fault find this evening after I have the typical boost 'jerk' on my 1.8t. Can I just do a sanity check to ensure that I understand the operation of the boost solenoid. If I apply a 12v source across the pins and I can hear the solenoid energise (click) and de-energise (click) can I assume that the solenoid is in actual fact fully functional and not faulty? Regards

10th April 2014, 12:01	#5
MG Tom Posted a thing or two ex. MG ZT+ Join Date: May 2013 Location: Northampton-ish Posts: 1,484 Thanks: 156 Thanked 98 Times in 95 Posts	To start with gap your plugs to 0.65mm and report back. __________________ '03 MG ZT+ 1.8T X-Power Grey with Monogram 'WTD' black alcantara trim. [SIGPIC][/SIGPIC] My project thread HERE

14th April 2014, 11:53	#10
MG Tom Posted a thing or two ex. MG ZT+ Join Date: May 2013 Location: Northampton-ish Posts: 1,484 Thanks: 156 Thanked 98 Times in 95 Posts	Result! I was sure that'd sort it. __________________ '03 MG ZT+ 1.8T X-Power Grey with Monogram 'WTD' black alcantara trim. [SIGPIC][/SIGPIC] My project thread HERE

7th April 2014, 20:59	#2
speeddevil68 Regular poster Rover 75 Tourer Connoisseur SE Join Date: Aug 2013 Location: Glasgow Posts: 73 Thanks: 0 Thanked 8 Times in 8 Posts	Are you able to read the boost pressure? (OBD, T4, IPK??)

10th April 2014, 11:22	#4
Nebburns Regular poster MG ZT-T Join Date: Dec 2013 Location: Midlands Posts: 30 Thanks: 3 Thanked 2 Times in 2 Posts	Anyone else?! Thanks

14th April 2014, 11:27	#9
Nebburns Regular poster MG ZT-T Join Date: Dec 2013 Location: Midlands Posts: 30 Thanks: 3 Thanked 2 Times in 2 Posts	Hello again, Sorry it took me slightly longer to come back however - ITS FIXED! Plug gap set to 0.65 and no more misfires! Thank you both for your help! Ben.