Coil Pack Problem...i Think.

September 5, 2010

Hello all, I`m a new member, just joined today but I have been around Toyota since 1982. Problem with a treasured family Toyota that I currently care for, hoping you can help. Avensis 2.0 petrol, not VVTi,1999reg. Last year it started to misfire at low rpm, around 1100, then also at just under 2000rpm. Changed plugs and all was well for three weeks.Toyota dealer recommended Toyota plugs so I changed them and all was well for about two months. A friend sprayed the leads with WD40 and hey presto, the problem disappeared for about three months. Decided problem must lie with the plug leads so changed them and all seemed well for around 18000 miles. I realised plugs were due for change so got new Toyota plugs, guess what...all was well for 3 weeks! I've tried the WD40 again on individual leads and it seems to be on number 1 and number 4 leads, both connect to same coil pack. Is it the coil pack and would that effect the leads as well as the plugs? and would also love to know why applications of WD40 alleviagte the problem for a while.

September 5, 2010

Welcome to the club!

I've moved your topic to the Avensis forum so the 'experts' in there will see your questions ;)

September 5, 2010

Hello all, I`m a new member, just joined today but I have been around Toyota since 1982. Problem with a treasured family Toyota that I currently care for, hoping you can help. Avensis 2.0 petrol, not VVTi,1999reg. Last year it started to misfire at low rpm, around 1100, then also at just under 2000rpm. Changed plugs and all was well for three weeks.Toyota dealer recommended Toyota plugs so I changed them and all was well for about two months. A friend sprayed the leads with WD40 and hey presto, the problem disappeared for about three months. Decided problem must lie with the plug leads so changed them and all seemed well for around 18000 miles. I realised plugs were due for change so got new Toyota plugs, guess what...all was well for 3 weeks! I've tried the WD40 again on individual leads and it seems to be on number 1 and number 4 leads, both connect to same coil pack. Is it the coil pack and would that effect the leads as well as the plugs? and would also love to know why applications of WD40 alleviagte the problem for a while.

hi im also a new member today i had this problem with a ford focus the water was coming through windscreen washer jets on bonnet when it rained or car was washed and water was going onto leads it sounds like water ingress maybe u could try ignition sealer [spray] on leads and see if that helps also make sure leads not lying against metal

September 6, 2010

Hello all, I`m a new member, just joined today but I have been around Toyota since 1982. Problem with a treasured family Toyota that I currently care for, hoping you can help. Avensis 2.0 petrol, not VVTi,1999reg. Last year it started to misfire at low rpm, around 1100, then also at just under 2000rpm. Changed plugs and all was well for three weeks.Toyota dealer recommended Toyota plugs so I changed them and all was well for about two months. A friend sprayed the leads with WD40 and hey presto, the problem disappeared for about three months. Decided problem must lie with the plug leads so changed them and all seemed well for around 18000 miles. I realised plugs were due for change so got new Toyota plugs, guess what...all was well for 3 weeks! I've tried the WD40 again on individual leads and it seems to be on number 1 and number 4 leads, both connect to same coil pack. Is it the coil pack and would that effect the leads as well as the plugs? and would also love to know why applications of WD40 alleviagte the problem for a while.
hi im also a new member today i had this problem with a ford focus the water was coming through windscreen washer jets on bonnet when it rained or car was washed and water was going onto leads it sounds like water ingress maybe u could try ignition sealer [spray] on leads and see if that helps also make sure leads not lying against metal

September 6, 2010

Hi, and thanks for your reply. I have heard of that sort of thing, however it can be dry hot weather or wet; makes no difference. No sign of water ingress under the bonnet at all and leads are definitely not touching any metal. I`ve narrowed it down to two leads that both connect to the same coil pack so I'm suspecting it will be the coil pack, although i don't think its a common fault with Toyota. I'll post information when its sorted out (hopefully)for the benefit of other owners who might experience the same thing.