Sharpie Posted April 13, 2003 Share Posted April 13, 2003 I swapped out my spark plugs last weekend and want to know if the old ones can tell me anything about how she is running ? I have looked here: http://www.mkiv.com/techarticles/read_plug/plugdiag.jpg http://www.ngkntk.co.uk/tips/fouling.htm http://www.ngkntk.co.uk/tips/preign.htm but, can not find an exact match. Can any of you more experienced chaps help ? Pic of old plugs - Quote Link to comment Share on other sites More sharing options...
Sharpie Posted April 13, 2003 Author Share Posted April 13, 2003 Just to add: - I do not know how long they have been in the car and keep forgetting to ask at the dealership. I have now had the soop just on 12 months/9k miles. Quote Link to comment Share on other sites More sharing options...
Darren Posted April 13, 2003 Share Posted April 13, 2003 Peter, They should be a nice brown colour. Yours look a bit white in the pics? I think that means lean runnin...but stand to be corrected. They look quite old though! Darren Quote Link to comment Share on other sites More sharing options...
Supra Pilot Posted April 13, 2003 Share Posted April 13, 2003 Engines looks like it's running sweet! Some may say 'lean', but plugs arn't supposed to really be too disscoloured.....so it looks like the engine is buring and running clean/good. 'This also depends on when you removed the plugs', if you just removed them after a nice long hardish blast, then they will/should be the colour of yours above. I will say that they should be changed though, as they look like they have been in the car for a long time.....by looking at the stem(ceramic) and also the tip/electrode! Quote Link to comment Share on other sites More sharing options...
Darren Posted April 13, 2003 Share Posted April 13, 2003 Oh well, Leon changed mine this week and said the brown colour was spot on for correct fuelling...and these engines are so cheap to fix if they go bang;) Darren Quote Link to comment Share on other sites More sharing options...
Alex Posted April 13, 2003 Share Posted April 13, 2003 I helped Peter change his plugs at Santa Pod. They were defo whiter than they should be. They were also stock plugs which did need to be replaced 'cause Peter is now running higher than stock boost. The Miss-fire cleared up straight away....which is an indication that the old plugs were out of their league. The comparison charts are not conclusive but I would say they were mainly just knackered and running slightly too hot! but they could have had those problems mixed with some carbon depositing. I'd treat her to come in-fuel cleaners to make sure there are no issues with the fuel system. Toluene is good at cleaning the fuel system out! Quote Link to comment Share on other sites More sharing options...
Steve Cargill Posted April 13, 2003 Share Posted April 13, 2003 Pete, did those plugs come out of the same car? The one on the left is V different, it's clean around the 'nut' where the other two are filthy and also it's a different colour. Quote Link to comment Share on other sites More sharing options...
Sharpie Posted April 13, 2003 Author Share Posted April 13, 2003 Hi Alex, thanks for filling in some of the blanks here…. Yes, only recently upped the boost on stock plugs and CW told me that I *might* misfire but, to see how it goes. (It was only the week before that I had RLTC fitted. ) So, during the winter weather I assumed that it was RLTC cutting in when, on slightly damp roads or on dry roads but, due to the cold temps still not having great traction when the second turbo had just kicked in. (Have good tread on my rubber) Then in the last few weeks the sun was out, the temps were up and we had a couple of dry sunning days and I was still having RLTC kick in. I thought, how can RLTC be kicking in when it is warm and bone dry so, assumed that I was misfiring never experienced a misfire before….. Alex and I changed the plugs at POD and I found on the way home that I was still suffering I then switched RLTC off the WET setting and could boost fine (Only for a test session) So, I was not misfiring in the first place but, am glad that I swapped out the plugs as things to not look that good at the mo. Other missing info:- I had just done one run at POD when these were taken out. I think it is time to visit someone with a Wide Band 02 Sensor Kit just to be on the safe side. Quote Link to comment Share on other sites More sharing options...
Darren Posted April 13, 2003 Share Posted April 13, 2003 I think it is time to visit someone with a Wide Band 02 Sensor Kit just to be on the safe side. Peter, That sounds like an excellent idea. Darren Quote Link to comment Share on other sites More sharing options...
Sharpie Posted April 13, 2003 Author Share Posted April 13, 2003 Yes Steve, all out of one car. All of the electrode insulators are starting to go brown but, this one is the worst. All the others are like the lighter colour ones with bits of brown starting to show. F.Y.I. The stock plugs taken out were Denso PK20R11 Quote Link to comment Share on other sites More sharing options...
Supra Pilot Posted April 13, 2003 Share Posted April 13, 2003 Originally posted by Darren Oh well, Leon changed mine this week and said the brown colour was spot on for correct fuelling...and these engines are so cheap to fix if they go bang;) Darren I made a blind statement Darren as you can't be 100% correct in a plug diagnosis from a photo, your moniter colour/tint/contrast etc may be set different to mine or someone elses on here. What I can say is the electrode/tip looks worn and the ceramic insulation also looks poor condition(not dirty). Quote Link to comment Share on other sites More sharing options...
Darren Posted April 13, 2003 Share Posted April 13, 2003 Supra Pilot Didn't mean to offend u! I agree those plugs look well past their best..... Darren Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted April 13, 2003 Share Posted April 13, 2003 Originally posted by Steve Cargill Pete, did those plugs come out of the same car? The one on the left is V different, it's clean around the 'nut' where the other two are filthy and also it's a different colour. Steve - It always seems that plug bores No5 & 6 collect the most crap. Could be the reason for the differing colour insulators. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted April 13, 2003 Share Posted April 13, 2003 Whoa fellas! Plug reading is a dying art and much misunderstood. But the important thing here is a plug read MUST be taken like this. Full throttle, maintained for say 5 seconds, kill the engine immediately, coast to a halt in neutral. Read the plugs. Caveats: ANY period of idling makes a reading meaningless, unleaded fuel makes plug reading 10 times more difficult to meaningless. The lead in the old "proper" fuels were what made the colour changes as much as anything. Honest answer is reading plugs on road cars run on unleaded is a waste of time unless it's so rich as to be belching blacks smoke or so weak as to be melting a plug. Unleaded fuels need mixture checked with wide band Lambda sensor and readout to be frank. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted April 13, 2003 Share Posted April 13, 2003 And by the way, those plugs in the photo look knackered to me, centre electrodes worn away. Even the bodies look like they have been at the bottom of the sea a few years Quote Link to comment Share on other sites More sharing options...
Sharpie Posted April 14, 2003 Author Share Posted April 14, 2003 Thanks Chaps. Chris, do you have a wide band Lambda sensor ? I guess it would fit nice into the adaptor you fitted in my DP last time Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted April 14, 2003 Share Posted April 14, 2003 Yes, I use Motec wide band mixture equipment. Quote Link to comment Share on other sites More sharing options...
Tony Smiley Posted April 15, 2003 Share Posted April 15, 2003 The one on the left looks just right to me! T Quote Link to comment Share on other sites More sharing options...
Sharpie Posted April 16, 2003 Author Share Posted April 16, 2003 Well, I'll know for sure soon enough! Quote Link to comment Share on other sites More sharing options...
Sharpie Posted May 14, 2003 Author Share Posted May 14, 2003 Had my fuelling checked by CW on his Motec while on my hols and it did need a slight alteration. All happy now Thanks Chris. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.