What do these plugs tell ya?
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What do these plugs tell ya?
I been killing plugs on my turbo 4.8 build. Fresh plugs it runs fine but not for long. I'm running 13lbs of boost with a stock ls1 241 head. I done a compression test and the cylinders were 136-141 and I'm running a stock cam. Tr6 plugs at .036 gap. Can anyone share any advice?
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#11
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136-140 is pretty low compression. So it's either really fat or you got oil in the cylinder. Do they stink of gasoline when you pull them out? What's the wideband say? If you don't have one, you should.
People, you should have a wideband mounted and installed in the car before you even consider putting a power adder on of any kind.
People, you should have a wideband mounted and installed in the car before you even consider putting a power adder on of any kind.
#13
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Wideband shows 11.9/12.2 it was tuned by a very skilled tuner, we are gonna do some more tuning to see if we can improve fuel mileage an spend some more time on it but I would like to find this problem before I go back since he is over 2 hours away. I don't think rich would be causing it to start running bad but run great on fresh plugs, do you? I changed coil packs last night thinking mine may have been tired from 220k miles. Same plugs and she still broke up. Gonna tighten the gap up on a fresh set next and see how long she last before it starts to go south again.
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No smell no wetness on plugs, appear great except down inside the threads. The blackness is actually kind of flaky. I cleaned one really good after cutting it open. It might have slight cracks in it but I can't see them and a razor blade won't grab them.
#16
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Those look like they have a lot of drive time on them to me. If you want to get fuel close you will have to warm car up and then put new plugs in. Make a full WOT pull and kill ign at the end and pull plugs. Every person is going to have what they call a clean plug. Just depends on how you want to run your timing. If you are trying to put as much timing as possible your probably not going to be able to clean up the fuel ring as much as if you were to back the timing down and ten clean fuel up. The easiest is to back timing down clean fuel ring up and then slowly add timing. Remember any time you add timing you have to add fuel or take timing take fuel. Hope that makes sense. I know that Turbo and Nitrous are different but here is a plug from when I was cleaning up my old nitrous tune. I would think a clean tune would be a clean tune turbo or nitrous.
Last edited by FASTFB; 02-06-2013 at 09:42 AM.
#17
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Yea it's a daily driven truck, tow rig but a toy as well. These plugs were driven on, I have never shut it off after spooling turbo because I wanted the oil to cool down inside it. Thanks for the pics, I will change some gap and work with it, I will report back when I get it figured out! Thanks a bunch for your help folks!!
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unfortunately you cant read a plug that has been drivin on it tells you nothing about your fueling. Without doing a WOT plug pull you dont know if its your WOT fueling or could be idle or mid fouling the plugs. If your wideband is showing 11.9-12.2 at WOT I would sure think you have an idle or part throrttle issue? Unless your wide band is incorrect?
#19
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That timing mark is pretty far down the strap IMO as well. Generally you can get by with a touch more on a FI car vs nitrous but its still aggressive. Def need to check out what is causing the plugs to foul up. It's rich somewhere... Then again it may not be due to compression. Light throttle may not be generating enough heat to clean the plug off. That would mean you need to lean it some at light throttle and put some more timing in it at partial throttle. Keeping the plug warm under normal conditions will help keep them cleaned off.
#20
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If its a truck tuned with a MAF that tows a lot I bet there is some horrible transition areas in the tune up. I get a ton of them in here tuned by other places. Tipping in at 0-1psi they will be at 11:1 with no timing in them already. Need to have that thing at 12.8-13:1 at 0psi and 26+ degrees of timing.