Some friends recently helped me out with a plug change. When we removed the plugs they were in bad shape... a few of them were really crusty looking but all pointed to the truck running very lean. My question is...how the hell is this possible with a stock tune?

These were the stock plugs at 50k miles... I had a chip that I ran until about 25-30k miles ago. Im only running a 2 LB lower .... and I have been back on the stock tune for over 25k miles now. Any ideas?

 

I think the first question most will ask is, when was the last time you changed your fuel filter ?, if its been more than 5000 miles then that could be your problem, ask Rob 02, he has some pictures of what a plugged fuel filter can do to plugs, and it wasn`t good.

 

I had my A/F checked when I first got my truck. It had like 500 miles on it and was bone stock, the A/F was 12.6.

My original post was in this Thread , and some people said that I was too lean.

 

Im on my 4th fuel filter at the moment.... I need to get on a dyno before I start modding again for race season..... but those plugs have me worried....just glad we changed them when we did... couldnt have gone too much further on that set

 

Don't you need a tune for the C&L 80mm mass air? I have no clue, just asking.

 

Are you still running the 2lbs lower with your stock tune? I've seen those with stock tune's and 2lbs lowers run around 13.7-14 a/f on the dyno.

 

Steve: Nah, if it was a 85 or 90 then yeah, but 80 is stock anyway



min150: Yeah, Id say its been on there for about 10k miles now....or around there. I have been told the stock computer can adjust for it, I would think I would throw some sort of SES code if the A/F was out of stock range.

 

Let me see if I can find the dyno chart and post the link of what I was talking about. This guy never had a code thrown. I'm not sure but I think it won't throw a code until it is way too lean. I mean in closed loop the truck is setup to run fairly lean for emission purposes.

I have a calibrated a/f meter and I can only read it when I'm in open loop. In closed loop it is a lot leaner and not on the visible range.

Also the stock computer can only adjust so much when you're in open loop. Which is basically as soon as you are not cruising or idling. It is limited to what is in your tables and depending on the air conditions where you live it may not be enough for a 2lbs lower.

edit: Well can't find the one I had in mind, but here is another one with stock computer and 2lbs lower. This one is in Houston where the weather is often hot and humid so poor air quality for the lightning. http://www.svt-enthusiast.com/albums/RUNVS/Rsi_dyno.jpg

 

I have always been told that the stock tables could allow for the added boost. Guess there is only way way to find out.... Im sure not going to risk it....especially for just a 2#er

 

I have been running a 4# for almost 2 years now with the stock program, A/F 12.5 (same as stock), no worries.

 

Hopefully nothing will happen in the mean time.... I have too much stuff to pay for right now with my new house.....cant really afford a breakdown of any kind .... I will just have to keep my fingers crossed until I can snag a hand held tuner or get on a dyno

 

Hopefully nothing will happen in the mean time.... I have too much stuff to pay for right now with my new house.....cant really afford a breakdown of any kind .... I will just have to keep my fingers crossed until I can snag a hand held tuner or get on a dyno

 

I would drop the fuel filter and change it just to be sure (cheap insurance)
But what somebody's else's truck should not and will not have any bearing on your truck. Every truck respnds differently to the same mods, so something to that effect

Good Luck in finding the problem and correcting it. Because I know the feeling of worring about the truck with a new/old house.

 

the current fuel filter only has about 3k miles on it right now.... damn my truck....I have been lucky though, so I cant be too upset.... just need to rest my fears by winter or no racing for me. Thanks for the responses