Over fueling

gmduramax

Shits broke
Jun 12, 2008
3,760
47
48
Nor cal
JoshH, I found my answers, found a efi live post from 2010 where it was added to efi live. . Grams/cyl & Play with air PID to get it to work. It is air to fuel ratio.
Adding fuel pressure at Idle helped Lope and cleaner burn at idle, (its a van ecu so needed 60 at idle,instead of 40.
Now as you said way back then “I have a set of 80% over injectors and my truck would have billows of smoke rolling from the exhaust if I wasn't careful. I have fine tuned it to a haze that quickly dissipates, but I can easily make it completely disappear but drivablilty suffers if I do that.”
Now I have 100% over injectors with 480/366 compounds. Is it possible to limit the bellows of smoke and make turbos light quicker on the launch without hurting performance.? Or does it just take Compounds fuel and time to get up to boost?
What are you doing with timing? Are you using a timing calculator?
 

Max1957

Wcarman 57 LBZ Badd Gass
Sep 26, 2021
27
0
1
NY
What are you doing with timing? Are you using a timing calculator?
Yes used a calculator. The tune I got was really good and set for 60% Overs. Just had a lope at Idle in gear. Now I went to 100 overs .. Got the Idle cleaned up now. Can start it in garage and it doesnt smoke me out. It sounds and runs great as it is. Just quite smokey spooling So will try lambda to see if it spools faster and cleaner And need to watch EGT’s to see what they Are. It leaves a good haze after boost where I think it should be. Probably Pushing it quite hard but its only 10 seconds, not pulling a load.
 

2004LB7

Well-known member
Dec 15, 2010
3,449
241
63
Norcal
if you have a hard time getting it cleaned up and you've exhausted all fuel related tuning you may need to look at the converter too. maybe too tight. also shift points can help tremendously too. getting it to downshift into one lower gear to help raise RPMs. the trick is to keep it from unlocking the converter. works wonderful for my tune. of course I don't have your setup either
 

gmduramax

Shits broke
Jun 12, 2008
3,760
47
48
Nor cal
Yes used a calculator. The tune I got was really good and set for 60% Overs. Just had a lope at Idle in gear. Now I went to 100 overs .. Got the Idle cleaned up now. Can start it in garage and it doesnt smoke me out. It sounds and runs great as it is. Just quite smokey spooling So will try lambda to see if it spools faster and cleaner And need to watch EGT’s to see what they Are. It leaves a good haze after boost where I think it should be. Probably Pushing it quite hard but its only 10 seconds, not pulling a load.
Take this with a grain of salt because I’m not as experienced with tuning. But throw 2 degrees of timing in your spooling area. See how it reacts, listen to the motor. In my understanding you can run more timing with larger injectors and not increase cylinder pressure because you’re using less Us with a bigger injector. Not really at low rail pressure because it takes longer for the fuel to get into the cylinder when the injector opens. If that doesn’t work try going the other way and pull 2 degrees out
 

Max1957

Wcarman 57 LBZ Badd Gass
Sep 26, 2021
27
0
1
NY
Take this with a grain of salt because I’m not as experienced with tuning. But throw 2 degrees of timing in your spooling area. See how it reacts, listen to the motor. In my understanding you can run more timing with larger injectors and not increase cylinder pressure because you’re using less Us with a bigger injector. Not really at low rail pressure because it takes longer for the fuel to get into the cylinder when the injector opens. If that doesn’t work try going the other way and pull 2 degrees out
Thats the only Question I have is the Pulsewidth. It has the 60overs Pulsewidth in it so should that be cut backed down and add a little timing. When guys say they have “” 2900us tune”” , where are they getting that Number?? Just the highest pulsewidth on the table? I hate to adjust it as it runs so well.
 

gmduramax

Shits broke
Jun 12, 2008
3,760
47
48
Nor cal
Thats the only Question I have is the Pulsewidth. It has the 60overs Pulsewidth in it so should that be cut backed down and add a little timing. When guys say they have “” 2900us tune”” , where are they getting that Number?? Just the highest pulsewidth on the table? I hate to adjust it as it runs so well.
they’re talking 2900 uS at the highest point of of their fuel pressure and MM3 so full throttle. Usually with injectors the pulse table doesn’t need to be modified other than the max pulse width
 

Max1957

Wcarman 57 LBZ Badd Gass
Sep 26, 2021
27
0
1
NY
if you have a hard time getting it cleaned up and you've exhausted all fuel related tuning you may need to look at the converter too. maybe too tight. also shift points can help tremendously too. getting it to downshift into one lower gear to help raise RPMs. the trick is to keep it from unlocking the converter. works wonderful for my tune. of course I don't have your setup either
4L80E Torque Convertor Could be a little tight, but any looser and engine hit 4000 rpms before I get speed up. Shifting with torque locked is out of the question, I broke a shaft in about 10 minutes last time I tryed. (Custom Built, Billet, hardened everything) Also it sends me sideways when locked in at low RPMs , Because of the torque in mid range.. Torque is set to lock in 3rd gear 85 mph 3800 rpm and it will chirp tires. (Yes need to tub it.)
Does not smoke bad while moving, it will down shift and then relock torque convertor. It is just the launch which I have a feeling it needs the fuel to get turbos spinning. But will try a little less fuel , maybe it will surprise me.
 

gmduramax

Shits broke
Jun 12, 2008
3,760
47
48
Nor cal
In a perfect world you would run less than 2000 uS anything over that you’re injecting fuel outside of the bowl and creating cylinder pressure when the rod to crank angle isn’t as efficient
 

Max1957

Wcarman 57 LBZ Badd Gass
Sep 26, 2021
27
0
1
NY
they’re talking 2900 uS at the highest point of of their fuel pressure and MM3 so full throttle. Usually with injectors the pulse table doesn’t need to be modified other than the max pulse width
Yes So im 120mm3 x 190 MPA , 2550us. Im not really smokey up there so going to leave it there.
 

Max1957

Wcarman 57 LBZ Badd Gass
Sep 26, 2021
27
0
1
NY
I
In a perfect world you would run less than 2000 uS anything over that you’re injecting fuel outside of the bowl and creating cylinder pressure when the rod to crank angle isn’t as efficient
Ok, that what I needed to hear. Also I want to say timing is about 7-9 degrees while trying to boost , I ussually try to ease into throttle 25-50% ,seems to boost a little quicker.
 

Dozerboy

Well-known member
Jun 23, 2009
4,428
78
48
TX of course
You generally don't get better spooling when you reduce smoke. Spooling will probably get worse, but you might be able to make it up with less timing and more fuel pressure.
 

S Phinney

Active member
Aug 15, 2008
4,003
11
28
Quncy, Fl
Thats the only Question I have is the Pulsewidth. It has the 60overs Pulsewidth in it so should that be cut backed down and add a little timing. When guys say they have “” 2900us tune”” , where are they getting that Number?? Just the highest pulsewidth on the table? I hate to adjust it as it runs so well.
In the idle spooling area you will find the fueling if the 100’s may be less fuel than the 60’s. Especially in the 10mm3-20mm3 and lower rail pressures. That’s the main reason the engine loped with the 60 over tune. It didn’t have enough fuel so it jumped back and forth in the table to find the fuel to idle.


Sent from my iPhone using Tapatalk
 

Max1957

Wcarman 57 LBZ Badd Gass
Sep 26, 2021
27
0
1
NY
In the idle spooling area you will find the fueling if the 100’s may be less fuel than the 60’s. Especially in the 10mm3-20mm3 and lower rail pressures. That’s the main reason the engine loped with the 60 over tune. It didn’t have enough fuel so it jumped back and forth in the table to find the fuel to idle.


Sent from my iPhone using Tapatalk
yes, The reason it loped was we had truck ecu fuel pressures 40 at idle in our tune. I have a Van ecu which for some reason needs 60 at idle. As soon as we bumped it up lope is gone.
 

monster50iii

Member
Dec 5, 2014
323
5
18
If you want better spool to launch harder, reduce timing. I reduced timing alot, from 8deg to 0-2deg in my spooling area and it helped alot. 2deg change won't be too noticeable.
 

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