08 chevy silverado hard start help

08 chevy silverado hard start help 6.2 heads cam fbo 90lb fic injectors, im having issue getting it started without depressing gas pedal I have the beginners tuning school book and online course followed all instructions and no luck been chasing my tail any help will be appreciated here is a file Attachment 95819

That's an indicator that you need more startup airflow. Add at least 20% more airflow above 111 deg coolant temp. Then add 10-15% more at a time until you get a nice startup.

Does it startup ok when cold?

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Originally Posted by kevin87turbot

That's an indicator that you need more startup airflow. Add at least 20% more airflow above 111 deg coolant temp. Then add 10-15% more at a time until you get a nice startup.

Does it startup ok when cold?

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I added up to 40-50% and no luck so i backed it off , no not even cold , i dialed in the injector data to what fic excel sheet has don't know if i missed something

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Originally Posted by the demon

I added up to 40-50% and no luck so i backed it off , no not even cold , i dialed in the injector data to what fic excel sheet has don't know if i missed something

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The Injector Flowrate table is the most important one to get right. It's not correct. It's just maxed out at 63.5.
You'll need to scale the injector data. In order to do that, you'll have to divide the actual injector flow rate by 2, then you'll multiply the Stoich AFR table by 2.

I don't recall if cylinder volume matters on the GEN 4 computers like it does in the GEN 3's but .85213 is not correct for a 6.2 engine size.

Kevin is right, the injectors can be scaled better. Double the stoich, half the injector flow rate and half the IVT terms. That will now give you an injector room of 127lb/hr instead of 63.5lb/hr. Then just tune in Lambda. Go back over the MAF and VVE to fine tune everything.

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Originally Posted by kevin87turbot

The Injector Flowrate table is the most important one to get right. It's not correct. It's just maxed out at 63.5.
You'll need to scale the injector data. In order to do that, you'll have to divide the actual injector flow rate by 2, then you'll multiply the Stoich AFR table by 2.

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Damn i got lost there dont have a clue how to do it

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Originally Posted by 5FDP

I don't recall if cylinder volume matters on the GEN 4 computers like it does in the GEN 3's but .85213 is not correct for a 6.2 engine size.

Kevin is right, the injectors can be scaled better. Double the stoich, half the injector flow rate and half the IVT terms. That will now give you an injector room of 127lb/hr instead of 63.5lb/hr. Then just tune in Lambda. Go back over the MAF and VVE to fine tune everything.

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Is there any video on how to scale them cause im really lost and i would really like to know how to do it, its hard to find good tuners here were im from ive been tuned by a couple always having trouble to get my truck dialed in right thats why i decided to buy hptuners to do it myself

I typed it lol.

Take the Stoich fuel table and just double, so mutiply the whole table by 2. It'll make the stoich 29.XXX and sloping downwards like you see it now.

Then take your 90lb/hr injector data that you got with the injectors and divide that by 2. Those values will not fit under the 63.5lb/hr limit the table currently has.

Then to the right of that is the table called IVT Terms, (AFR TERM) take that table and just divide it by 2.

This is the quick way to "scale" the fuel injectors. It's works pretty well.




Because of the double stoich using AFR to tune isn't really ideal anymore, so just use Lambda with your wideband like most already do.

Quote:

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Originally Posted by 5FDP

I typed it lol.

Take the Stoich fuel table and just double, so mutiply the whole table by 2. It'll make the stoich 29.XXX and sloping downwards like you see it now.

Then take your 90lb/hr injector data that you got with the injectors and divide that by 2. Those values will not fit under the 63.5lb/hr limit the table currently has.

Then to the right of that is the table called IVT Terms, (AFR TERM) take that table and just divide it by 2.

This is the quick way to "scale" the fuel injectors. It's works pretty well.




Because of the double stoich using AFR to tune isn't really ideal anymore, so just use Lambda with your wideband like most already do.

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Ok let me try it lol hope it works let me follow the steps i really appreciate your help

Thanks guys i now have learned to scale for larger injectors i will upload file in the morning and will keep you guys posted hopefully this was my issue thanks once again

Is there anything else you have to move when scaling injectors couldnt make it to work

For the injector themselves, no not really. Doing the double stoich, half the IFR and half the IVT terms is the quick way to scale them.

You still have to take the time to tune the fueling with the MAF curve and the VVE tables. It's likely possible you may need to mess with injection timing too. Even things like crank fuel may need changing.

Other factors are timing and idle airflow settings to make it run well.

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Originally Posted by 5FDP

For the injector themselves, no not really. Doing the double stoich, half the IFR and half the IVT terms is the quick way to scale them.

You still have to take the time to tune the fueling with the MAF curve and the VVE tables. It's likely possible you may need to mess with injection timing too. Even things like crank fuel may need changing.

Other factors are timing and idle airflow settings to make it run well.

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Ok let me keep on trying i can start it depressing the gas pedal but from there on i can do the maf curve but still struggling to start let me keep on but since i havent been able to do the start up havent really messed with the maf curve and vve thanks again just wanted to make sure i wasnt missing anything on that