Yellow Bullet Forums banner

1 - 17 of 17 Posts

·
Registered
Joined
·
1,419 Posts
Discussion Starter #1
ive been having some issues with my ls ever since i put my good motor in... when i first installed it and fired it up it was very responsive/crisp throttle reacting... after it ran for a few minutes i shut it off and since then i have had nothing but issues....lazy throttle response, sometimes it wont even start up after the first initial fire up without having to hold the throttle half open and then it runs so fat it wont even idle... i think i have found the issue with the starting problem and i replaced both sides of coils(2 plugs werent firing at all on one side and at least 1 on the other) and it will start up every time with out the help of the throttle being open..so i put new plugs(-10) in it and took it for a trip around the hood and made a few quik hits.. car seems lazy till its got some boost going to it, after that it pulls/revs good.... i let the car cool off and pulled the plugs and 2 look like i think they should, 1 is dark(fat) and the others look like there is either no fuel or theres spark blow out... the ones im wondering about all look like theres no heat anywhere in the plug and no visual sign of a heat mark, still golden color like it just came out of the box but the strap has the crusty look of the cad starting to burn off... 2 have a clearly noticeble timing mark and show heat in the base of the plug....in the middle of the last hit the afr(i have the afr map set at 11.0) on the left side got lean up in the boost/rpm range before the shift(6500) and i noticed that the #7 plug wire was off the coil so im hoping that was the cause of the lean spike, and the right bank is always 1 point higher unless its in the upper rpms/boost.. motor is controlled by a dominator and it keeps the afr in range thru the rpms for the most part... this is an e85 fueled 6.0 ls motor with no water in the block and heads..i cant figure out how to post pics... so im hoping that someone has been thru this and can help me figure out whats going on... motor has the ls truck coils on it, and this motor has some compression to it and im wondering if its got too much cylinder pressure for the coils to light off at upper rpms and high boost(19psi for now).. thanks for the help in advance.
 

·
Registered
Joined
·
19,622 Posts
Having one plug wire off makes the computer try and adjust-sounds more like it
needs to be tuned to the combo.
 

·
Registered
Joined
·
1,419 Posts
Discussion Starter #3
Having one plug wire off makes the computer try and adjust-sounds more like it
needs to be tuned to the combo
.
totally agree.. going over the datalogs its keeping the afr where its commanded for the most part... if i go by the plugs then there is alot of individual cylinder work tuning ahead... last motor in the car was a 6.0 w/cam and the cylinders were never this far off plug wise, same intake and turbo setup...
 

·
Registered
Joined
·
5,582 Posts
How are you monitoring engine temp?? How much compression is "some"??
How much are you trying idle/drive on -10 plugs?? I would run a -7 or -8 on low boost sorting things out.
What it dwell on coils??
I would run a leak down test on it before I did a lot of individual cylinder tuning. Why would this engine be so problematic when it is very similar to the one before it that didn't have these issues?? What has changed??
 

·
Registered
Joined
·
1,419 Posts
Discussion Starter #5
How are you monitoring engine temp?? How much compression is "some"??
How much are you trying idle/drive on -10 plugs?? I would run a -7 or -8 on low boost sorting things out.
What it dwell on coils??
I would run a leak down test on it before I did a lot of individual cylinder tuning. Why would this engine be so problematic when it is very similar to the one before it that didn't have these issues?? What has changed??
im monitoring oil temp as there is no water in this motor, comp. is 10.8, the reason for the 10 plugs is because its all i had at the shop at that time so i used them and its matbe a minute fron the time i start the car and make it to the gate and then its driving thru the hood for a total of about 4 minutes...3 stop signs and then 1,5 mile straight shot where i rev it to the top of first and then get out of it so that i can see whats going on, i do 3 hits like that in the time i leave the last stop sign and pull in the shop.. this is a fresh rebuild, after i shut it off i immediately roll the engine over listening for a dead spot like i use to do on my nos engine, no blow by and consistent rotating so i wasnt worried about a leak down... i can still do it to be sure .....engine isnt "just like" the last one and i didnt mean for it to sound like it was so sorry, this engine is all race oriented where the last engine was a sbe deal...
 

·
Registered
Joined
·
1,419 Posts
Discussion Starter #6
do large cams mess with the afr idling? is it possible thats why its lean(15left-16right afr) idling?
 

·
Registered
Joined
·
16,365 Posts
Having 1 dark plug is telling you something. With E85 and everything tuned decently you shouldn't see any color on the insulation.

Oil temp is a terrible way to monitor engine temperature. In my car it takes a LONG TIME to get oil temperature up above 150 deg F and by then my water temps have been over 180 for 5-10 minutes.
 

·
Registered
Joined
·
5,582 Posts
im monitoring oil temp as there is no water in this motor, comp. is 10.8, the reason for the 10 plugs is because its all i had at the shop at that time so i used them and its matbe a minute fron the time i start the car and make it to the gate and then its driving thru the hood for a total of about 4 minutes...3 stop signs and then 1,5 mile straight shot where i rev it to the top of first and then get out of it so that i can see whats going on, i do 3 hits like that in the time i leave the last stop sign and pull in the shop.. this is a fresh rebuild, after i shut it off i immediately roll the engine over listening for a dead spot like i use to do on my nos engine, no blow by and consistent rotating so i wasnt worried about a leak down... i can still do it to be sure .....engine isnt "just like" the last one and i didnt mean for it to sound like it was so sorry, this engine is all race oriented where the last engine was a sbe deal...
E85 is miles from methanol as far as running zero water. I would have head temp sensors like Racepak makes and even then would not run it that long. Its sketchy in my opinion even towing to the line, burnout and 1/8mi hit then tow back to the pits. That is way shorter than what you are trying to do. Not saying it can't be done but I would not do it unless it's on methanol. What gasket setup is on it??
 

·
Registered
Joined
·
1,419 Posts
Discussion Starter #9
yes its sketchy, oil temp gets as high as 160* after i pull in the shop after the test hits..cometic MLX...
 

·
Registered
Joined
·
1,419 Posts
Discussion Starter #10
Having 1 dark plug is telling you something. With E85 and everything tuned decently you shouldn't see any color on the insulation.

Oil temp is a terrible way to monitor engine temperature. In my car it takes a LONG TIME to get oil temperature up above 150 deg F and by then my water temps have been over 180 for 5-10 minutes.
the dark color is on the base of the plug not the porcelian... all the plugs porcelian are white...
 

·
Registered
Joined
·
1,419 Posts
Discussion Starter #11
maybe i can get ahold of troy and see if he can post the plug pics, i cant figure it out...
 

·
Registered
Joined
·
1,419 Posts
Discussion Starter #13
i guess my next move will be to get some plugs and lower the boost down and make some hits at the track where its gonna be loaded better than a street pull..

would running water in the upper hole of the block and out thru the steam ports of the front and back do a decent job of cooliong the heads? other than pulling the motor and pull the heads and do a solid head gasket and drilling and tapping the front and rear of heads.... thanks again everyone for the help
 

·
Registered
Joined
·
5,582 Posts
Better than nothing. We used to do external water lines on all the big power combos running 6-bolt All Pro heads to prolong the gasket life. Most of these were on C16 or Q16 and we were injecting cool water under each exhaust port thru individual 6AN lines. However I would be more concerned at the moment that it hasn't scuffed any pistons. Again I would do a leak down test before I ran it anymore.
 

·
Registered
Joined
·
409 Posts
10s on E85 ?

I thought it likes a hotter plug .

Hell , I run 8s up to 34psi on C16 .
Agreed. On my 10.4:1 6.0L at 22psi with 7’s, I see no heat on the plug.
Put some hotter plugs in it.
And I don’t see oil temp move for a good 10 minutes after engine is 180.
 

·
Registered
Joined
·
1,508 Posts
Flow the injectors, you can have 1 bad injector on a bank and the other 3 will make the afr target assuming 1 o2 reads 1bank. 8 cyls on 1 o2 will do the same, the good injectors will hit afr target when the others aint doing shit
 
1 - 17 of 17 Posts
Top