fox_forma Posted August 15, 2007 Report Share Posted August 15, 2007 Ok guys, my truck has been getting crappy mpg lately so I thought something was up. I have a W4M tune so I had Thunder from over on PT.net do some logging for me. Some things were a little off but my fuel trims were hitting I believe the 19 range with the W4M tune. Spoke with a highly regarded tuner about this, "not Jesse at W4M" and was told to get some more logging with my stock PCM which I just did. Now my damn fuel trims were up in the 25+ range when WOT. I was told there most likely is a leak somewhere and I'm trying to track it down before any damage or anything happens. Anyone else ever deal with something like this and find a leak? If so where? Also anyone else who has EFILive I would be more than happy to send over the logging files just for more insight although I have faith my new tuner contact will pull through just figured maybe others would like to see what the hell is going on. Oh yeah, I'm avg about 11mpg's now driving like a beotch, wtf. Quote Link to comment Share on other sites More sharing options...
SS_bnoon_SS Posted August 15, 2007 Report Share Posted August 15, 2007 (edited) I've never chased an air leak, but I did have one bad injector that caused the ECU to tell the remaining 3 injectors in that bank to dump fuel like a mofo. replaced the bad injector and all was well. To chase an air leak, the question is: Is it both banks or just one? If it's both, check for air leaks after the MAF in the intake tube, check the TB mounting area, and all vacuum hoses. If it's only one bank, check the inectors on that bank and the manifold to head gaskets... You can use a can of starter fluid to spray near a suspected leak (spray in short bursts, with several seconds between bursts). If the idle jumps up a few hundred RPM, you found a leak. Do it on a cool engine to avoid the obvious... Edited August 15, 2007 by SS_bnoon_SS (see edit history) Quote Link to comment Share on other sites More sharing options...
fox_forma Posted August 15, 2007 Author Report Share Posted August 15, 2007 The odd thing is the logs are showing fine with all the 02's and everything else, just something is causing my fuel trims to sky rocket. I took my Volant out today and adjusted it a little bit. The cheap ass gasket that goes between the box and MAF itself was eipped apart so I made myself something that will for sure seal it up. I also made sure the tube was connected to the TB better this time, before it seemed a little off and the TB was dirty inside for some reason. Since putting it back together again and cleaning the MAF the truck is idling a lot better but I am still most likely going to try and get some more logging done here shortly. Quote Link to comment Share on other sites More sharing options...
misterp Posted August 15, 2007 Report Share Posted August 15, 2007 What I've done in the past is screwed-up the intake tube between the MAF and TB - gotta make sure that the seals/boots are leak-free there or it will make fuel trims off by 20 or more. Mr. P. Quote Link to comment Share on other sites More sharing options...
fox_forma Posted August 15, 2007 Author Report Share Posted August 15, 2007 that was the first thing I did when I pulled the intake off. I cleaned everything real well and made sure it was a nice seal. With such little room to actually get leverage to install it back on the TB that could of been the case last time I had it off. I'm going to run a full tank driving normally and see if anything changes. At least I still got full warranty if anything goes south on me Quote Link to comment Share on other sites More sharing options...
misterp Posted August 15, 2007 Report Share Posted August 15, 2007 Yeah one time I got my head down in there by the alternator and saw that the rubber boot was off the TB & leaking at the bottom but looked fine from the top Quote Link to comment Share on other sites More sharing options...
fox_forma Posted August 15, 2007 Author Report Share Posted August 15, 2007 Yeah one time I got my head down in there by the alternator and saw that the rubber boot was off the TB & leaking at the bottom but looked fine from the top yeah I kinda had a feeling that may be the case as well since my TB was dirty inside which is def not a good thing. I will just keep an eye out on it for now before I can get more logging done. I just thought it was odd though because the truck was running fine and I was getting great gas mileage, then wham, starting running different and I was getting like 11mpg round town driving slow. Just hoping its not anything else major Quote Link to comment Share on other sites More sharing options...
fox_forma Posted August 15, 2007 Author Report Share Posted August 15, 2007 also, out of curiosity what is this extra plug for? I noticed it disconnected back near the Pass firewall but see nothing is could hook into? Quote Link to comment Share on other sites More sharing options...
Wheatley Posted August 15, 2007 Report Share Posted August 15, 2007 (edited) Are your fuel trims on bank 1 and bank 2 that high? Edited August 15, 2007 by Wheatley (see edit history) Quote Link to comment Share on other sites More sharing options...
fox_forma Posted August 16, 2007 Author Report Share Posted August 16, 2007 I dont have the graph in front of me since I cant read EFILive files but yes both were that high from what I remember. If you want I can email you my tuned PCM logging vs my Stock PCM and the stock was worse with the trims that is if you use EFILIVE Quote Link to comment Share on other sites More sharing options...
[email protected] Posted August 16, 2007 Report Share Posted August 16, 2007 also, out of curiosity what is this extra plug for? I noticed it disconnected back near the Pass firewall but see nothing is could hook into? could it be for the hood light if it is that easy im doing it tomorrow Quote Link to comment Share on other sites More sharing options...
fox_forma Posted August 16, 2007 Author Report Share Posted August 16, 2007 Just a thought that crossed my mind coming from a background of dirt bikes and ATV's but if I'm running lean wouldn't that have a tendency to wear out the plugs let alone possible burning the electrode off. Now if my truck has been running lean for some time now could my plugs be half way on the out and just not performing like they should? Quote Link to comment Share on other sites More sharing options...
04CHASE Posted August 16, 2007 Report Share Posted August 16, 2007 Just a thought that crossed my mind coming from a background of dirt bikes and ATV's but if I'm running lean wouldn't that have a tendency to wear out the plugs let alone possible burning the electrode off. Now if my truck has been running lean for some time now could my plugs be half way on the out and just not performing like they should? could be , you should pull one and anaylize it , mr p has a how to read a plug. or post a pic of it and we can help. Quote Link to comment Share on other sites More sharing options...
Black2003SS Posted August 16, 2007 Report Share Posted August 16, 2007 Pull a plug on each bank, snap a pic and post it...if its white and looks like it has white ash on it, you could be in trouble. A light oil brownish color and you are golden. If its black, you're rich. My fuel trims are out of whack also, but I was told everything is cool, and the fact I have FI would make it different. Are we talking about your short term or long term trims? Quote Link to comment Share on other sites More sharing options...
fox_forma Posted August 16, 2007 Author Report Share Posted August 16, 2007 Not to sure what short term or long term means in regards to this but at normal cruising speeds I believe they werent to bad but still higher than they should be. But at WOT I believe I hit over 26 on fuel trims which from what I gather is bad bad bad. As for reading plugs I saw Mr.P's How TO but also am curious can you do it like you would on a bike or ATV with a plug chop with the general rule of thumb having a 2mm tan ring showing your running correct? Quote Link to comment Share on other sites More sharing options...
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