Ignition with 1.5bar boost

classicswede · Oct 3rd, 2006, 20:54

I'm having ignition problems on a V70R that has been chipped and running on 1.5 bar of boost. Under full boost it has a missfire and no amount of adjusting the fueling helps.
What plugs leads and coil cap etc should be used with these. The leads are cap are new Volvo ones the plugs are new bosch v grove and it has a uprated coil (not sure on make)

Any ideas

Thanks

Pedro Fandango · Oct 3rd, 2006, 20:57

could closing the gap on the spark plugs help if the boost is blowing out the spark causing the missfire?

only an idea, i know ****

bobcat · Oct 3rd, 2006, 23:10

1.5 bar of boost?

are you sure its running that?

classicswede · Oct 4th, 2006, 20:40

I've closed the plug gap down to 0.7mm and that has got it almost spot on on petrol but it's still not enough for gas. Closing the gas anymore I'm sure will be too small.
Yes I am sure it is running 1.5 bar measured at the manifold - that is a lot of boost.

adieu · Oct 4th, 2006, 21:55

Perhaps larger injectors?

Just a thought.

regards

iain

Drew · Oct 5th, 2006, 11:20

Do you have a dump valve on the car?

classicswede · Oct 5th, 2006, 20:50

As far as I can see the car has had no modifications other than chipping the ecu. It is getting pleanty of fuel it just does not seem able to ignite it.

What spark plugs would you normaly use for a car that has had this type of modification?

I dont know who did the ecu work but all bar the missfire under full load it seems to drive and fuel spot on.

don kalmar union · Oct 6th, 2006, 07:59

Hello Classic Swede,

Could you tell us what year and particular engine that you have in the car and from whom you bought your 'chip'?

That would probably help in getting some more precise and informed opinion and advice.

Regards, Don.Norchi.

www.kalmar-union.com

Drew · Oct 6th, 2006, 13:35

I was chatting to someone about this post earlier and they mentioned the boost setting. He suggested dropping the gap to 0.6 or 0.55. Any boost above 1.4 ish bar you can expect plug blow out so dropping the gap is normally required.

hope it helps

classicswede · Oct 6th, 2006, 21:33

Don,
the car is not with me at the moment but if it helps it a R plate V70R AWD.
The ecu work had been done well before the car came to me so I have no idea who had done it. When it first came it was VERY slow but after a bit of driving and pulling the battery off and changing to the current bosch plugs it going a lot better.

Drew,
I think you are right the only way to get a good spark with the cylinder pressure involved with this amount of boost would be to close the plug gap. I think a change to single prong plugs would help as the V plugs can give erratic spark under exream loading from my experiance.

Thank you both for your imput so far.

Oct 3rd, 2006, 20:54	#1
classicswede Trader Volvo in my veins Last Online: Yesterday 19:12 Join Date: Dec 2004 Location: Anglesey	Ignition with 1.5bar boost I'm having ignition problems on a V70R that has been chipped and running on 1.5 bar of boost. Under full boost it has a missfire and no amount of adjusting the fueling helps. What plugs leads and coil cap etc should be used with these. The leads are cap are new Volvo ones the plugs are new bosch v grove and it has a uprated coil (not sure on make) Any ideas Thanks __________________ http://www.classicswede.org www.classicswede.co.uk

Oct 3rd, 2006, 23:10	#3
bobcat Premier Member Last Online: Apr 18th, 2024 11:37 Join Date: Dec 2004 Location:	1.5 bar of boost? are you sure its running that? __________________ Volvo 850R Auto,173K,Bobcat\SW Autos Ecu,18T,Reverse IC,13 Row Engine Oil Cooler,39 Row ATF Cooler,20psi VDO Boost Gauge,6000k HID's (low), Osram 50% Silverstars (High),ITG Filter,OEM Strutbrace,Aerial Down Switch,302mm Front Discs,Ferodo DS2500 Front/Rear,Goodridge SS Hoses,Koni Adjustable Dampers,Eibach Pro Kit, Powerflex Control Arm Bushes, Clear Side Repeaters. http://www.swautos.co.uk SW Auto's Ebay Shop http://www.volvo-tech.co.uk

Oct 4th, 2006, 20:40	#4
classicswede Trader Volvo in my veins Last Online: Yesterday 19:12 Join Date: Dec 2004 Location: Anglesey	I've closed the plug gap down to 0.7mm and that has got it almost spot on on petrol but it's still not enough for gas. Closing the gas anymore I'm sure will be too small. Yes I am sure it is running 1.5 bar measured at the manifold - that is a lot of boost. __________________ http://www.classicswede.org www.classicswede.co.uk

Oct 4th, 2006, 21:55	#5
adieu Master Member Last Online: Feb 5th, 2021 19:07 Join Date: Dec 2002 Location: swindon	Perhaps larger injectors? Just a thought. regards iain __________________ Speed has never killed anyone, suddenly becoming stationary… That’s what gets you. A turbo: Exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster

Oct 5th, 2006, 20:50	#7
classicswede Trader Volvo in my veins Last Online: Yesterday 19:12 Join Date: Dec 2004 Location: Anglesey	As far as I can see the car has had no modifications other than chipping the ecu. It is getting pleanty of fuel it just does not seem able to ignite it. What spark plugs would you normaly use for a car that has had this type of modification? I dont know who did the ecu work but all bar the missfire under full load it seems to drive and fuel spot on. __________________ http://www.classicswede.org www.classicswede.co.uk

Oct 3rd, 2006, 20:57	#2
Pedro Fandango I've Been Banned Last Online: Apr 2nd, 2015 16:12 Join Date: Dec 2002 Location: can't remember	could closing the gap on the spark plugs help if the boost is blowing out the spark causing the missfire? only an idea, i know ****

Oct 5th, 2006, 11:20	#6
Drew Member Last Online: Apr 8th, 2008 14:28 Join Date: Sep 2006 Location: St. Kitts	Do you have a dump valve on the car?

Oct 6th, 2006, 07:59	#8
don kalmar union Trader Last Online: Yesterday 12:01 Join Date: Dec 2001 Location: Chesham, buckinghamshire	Hello Classic Swede, Could you tell us what year and particular engine that you have in the car and from whom you bought your 'chip'? That would probably help in getting some more precise and informed opinion and advice. Regards, Don.Norchi. www.kalmar-union.com

Oct 6th, 2006, 13:35	#9
Drew Member Last Online: Apr 8th, 2008 14:28 Join Date: Sep 2006 Location: St. Kitts	I was chatting to someone about this post earlier and they mentioned the boost setting. He suggested dropping the gap to 0.6 or 0.55. Any boost above 1.4 ish bar you can expect plug blow out so dropping the gap is normally required. hope it helps

Oct 6th, 2006, 21:33	#10
classicswede Trader Volvo in my veins Last Online: Yesterday 19:12 Join Date: Dec 2004 Location: Anglesey	Don, the car is not with me at the moment but if it helps it a R plate V70R AWD. The ecu work had been done well before the car came to me so I have no idea who had done it. When it first came it was VERY slow but after a bit of driving and pulling the battery off and changing to the current bosch plugs it going a lot better. Drew, I think you are right the only way to get a good spark with the cylinder pressure involved with this amount of boost would be to close the plug gap. I think a change to single prong plugs would help as the V plugs can give erratic spark under exream loading from my experiance. Thank you both for your imput so far. __________________ http://www.classicswede.org www.classicswede.co.uk

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