Cross Posted May 25, 2014 Share Posted May 25, 2014 So put the Vette back on the dyno yesterday only to run into more fun problems. Nic had sent me a Gas tune because I was tired of the limited range on E85 and we had agreed to that when I first took the Vette to him for the E85 tune. (And to remove the Speed Density tune Big Poppa had Nic put on it before I bought it) Since putting the new heads (Brand new stock LS3's) on I have had a lot of problems with getting the car to idle and Nic has been understandably busy with his wedding (Congrats again to both of them) so I have tried to work through it but this area has always been my weak point... But I got some advice and it seemed to work out. After tweaking the Base Idle Airflow and Throttle Follow as well as working on the VE and MAF tables everything seemed to line up and it was idling well, not perfect like Nic could get it but not trying to die at times either, just a slight dip sometimes. So I thought we were ready to go only to get on the dyno and find it running leaner at WOT, 14's.... It wasn't doing this on E85 so I have no idea why it was doing it now. I don't think anything I changed effect's WOT and in total I only touched 4 tables. I tried pushing up the MAF tables (Upper end only 7.5k and up) three times, twice by multiplying it by 1.09 and then once by over 1.2x.... the best I got it to was low 13's... Duty Cycle went from 69% to 82%.... I did not have a fuel pressure tester with me, I did not expect that to be a problem since it already has an upgraded fuel pump and a boost a pump and was fine on E85... I checked it now and it's at 55-60 at idle but my tester is not long enough to test while driving. I went back to Nic's settings it got even leaner, way leaner.... off the gauge leaner... I just do not know what to think. I cleaned the air filter and MAF which were slightly dirty. I checked the injector's they look clean. I replaced the fuel filter 2 tanks after switching to E85 so it could catch any crap in the tank, that fuel filter has maybe seen 4000 miles if 2000... it's a Wix to not a cheapo. Looking for a few idea's here... I have the log's and dyno runs to I can send them to anyone since uploading them seem's to go oddly. Nic is still busy for some time and for me getting to phoenix is really a pain in the ass. I am hoping to figure something out... at this point I was going to start all over tuning the car starting with VE and moving on to the MAF again and seeing if that's the issue.... but I don't think it is... I am thinking this is something else. Thanks for any insight guys. Link to comment Share on other sites More sharing options...
LastC3 Posted May 25, 2014 Share Posted May 25, 2014 no certain I can help ... but just a couple of questions for clarification purposes ......... After the heads change ...... you re-flashed a modified stock tune back in the PCM ....??? Valve train adjustments are correct .??? You drained all the E85 out of the tanks and reloaded with 91 octane ???? If there still E85 in the system, the new tune would certainly make it lean ............ (i would think) ???? Maybe try the tune that was in it just prior to going to E85 ... just to confirm it may be something other then the tune ..??? Link to comment Share on other sites More sharing options...
Ted Y Posted May 26, 2014 Share Posted May 26, 2014 Vacuum leaks? Link to comment Share on other sites More sharing options...
Buccaneer Posted May 26, 2014 Share Posted May 26, 2014 Ask 417 to help you change your sun visors, it worked for him. Jus sayin'. Link to comment Share on other sites More sharing options...
MOTV8 Posted May 26, 2014 Share Posted May 26, 2014 Man. Do some voodoo or hire an exorcist to cast out whatever a-hole demon has made it's home in that vert. Link to comment Share on other sites More sharing options...
Cross Posted May 26, 2014 Author Share Posted May 26, 2014 no certain I can help ... but just a couple of questions for clarification purposes ......... After the heads change ...... you re-flashed a modified stock tune back in the PCM ....??? Valve train adjustments are correct .??? You drained all the E85 out of the tanks and reloaded with 91 octane ???? If there still E85 in the system, the new tune would certainly make it lean ............ (i would think) ???? Maybe try the tune that was in it just prior to going to E85 ... just to confirm it may be something other then the tune ..??? I think the A-Hole is behind the wheel... or at least some people tell me that. But to address these, it's been on gas for awhile now at least 2-3 tanks. When the heads were changed I asked Nic what needed to be changed he didn't feel much would since I went from ported LS3 heads to stock LS3 heads changing really nothing else but having the right rockers this time. I got annoyed with E85 mpg and switched the gas after he sent me a gas tune. The issue has just been the car does not like to idle and will stall off and on unless I keep it running, very annoying. It wasn't until this month that I noticed it was having issues going lean, it wasn't before that I remember, now it is which leads me to believe that while the idle issue was tune related this new issue probably is not... but I am stumped on why this issue is suddenly present. There is nothing that hasn't been changed in the fuel system now, it's all new... so either it's possible the fuel pump is fine at idle and dying up top and I need a replacement (Wonder about the warranty on that) or something has gone wrong somewhere else. I am getting my hands on a working stock fuel pump today... I am going to swap it out and see if the problem corrects itself or not. Also to be clear it could have been slightly lean before... but it is without a doubt much worse and the only thing I have changed is trying to make it idle nothing else. Link to comment Share on other sites More sharing options...
TheCMSH Posted May 26, 2014 Share Posted May 26, 2014 First thought I had was fuel pump, it'll be interesting to hear your report back after the change. Is it possible to flash back to baseline factory tune, drive it for awhile, then see where you are before adjusting? Link to comment Share on other sites More sharing options...
LastC3 Posted May 27, 2014 Share Posted May 27, 2014 So what has been changed is the heads ..... now with a bit less flow (non ported) .... and the rockers ..... how different were the ones you took off as compared to what's on there now ...... did the ones you put on reduce lift >??? .... between the two, you may see a leaner condition .... unless something else has changed ...???? Nic's tune likely took the flow/lift/duration conditions into consideration prior to the head/rocker change /??? Jim's recommendation could be a place to begin again ... because you're back to stock heads it certainly could be closer to what your motor is looking for ...... ..... at least until Nic can plug back in ..... and/or review you logs ... Link to comment Share on other sites More sharing options...
Cross Posted May 27, 2014 Author Share Posted May 27, 2014 Well today I put in Dange's new Upgraded Fuel pump and kept the lower that was working fine but not keeping up with his Supercharger kit. I also replaced his Fuel Filter and it got me thinking... why not try that first. I pulled my fuel filter and it was dirty on the inlet side, the outlet was clean but the inlet has enough to cloud the fuel. I checked Dange's and it was clean on both ends, put it on and went for a run, AFR @ 12.1 the whole time, tried it twice. I am having Chey grab me an OEM Filter tomorrow from her work but this leaves me asking another question... how bad would the fuel pump be then... It made it through the fuel sock and the pump... Should I just buy another fuel pump or was this just a case of I didn't wait long enough between changing to E85 than back to gas and there was enough to clog the filter. Link to comment Share on other sites More sharing options...
Desertdawg Posted May 27, 2014 Share Posted May 27, 2014 What I see.. Blah, Blah,Blah,Blah,Blah,Blah,Blah,Blah,Blah,Blah,Blah, Blah,Blah,Blah,Blah, Blah,Blah, Blah,Blah,Blah,Blah,Blah,Blah.. What I don't see.... Pictures of Chey! So put the Vette back on the dyno yesterday only to run into more fun problems. at leaset it's fun prolems now!! Remember, new doesn't always mean it works correctly... Link to comment Share on other sites More sharing options...
Cross Posted May 27, 2014 Author Share Posted May 27, 2014 What I see.. Blah, Blah,Blah,Blah,Blah,Blah,Blah,Blah,Blah,Blah,Blah, Blah,Blah,Blah,Blah, Blah,Blah, Blah,Blah,Blah,Blah,Blah,Blah.. What I don't see.... Pictures of Chey! So put the Vette back on the dyno yesterday only to run into more fun problems. at leaset it's fun prolems now!! Remember, new doesn't always mean it works correctly... Her picture is in every post I make now so you sir are going blind Link to comment Share on other sites More sharing options...
Desertdawg Posted May 27, 2014 Share Posted May 27, 2014 MOR pickturez, LESS clothes........ Link to comment Share on other sites More sharing options...
hd-wingnut Posted May 30, 2014 Share Posted May 30, 2014 MOR pickturez, LESS clothes........ Dude....you're starting to sound a little "horndoggish!" Should we change your name to Hornydawg? I agree...more pictures...less cloths! (I'm just agreeing...lol) Link to comment Share on other sites More sharing options...
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