How to lower IPW at idle??

[Ben Charles]

I have some 60lb Mototron Injectors (long ones if that even matters) and Im suppose to have the correct injector data. but on my last log the IPW at idle was 3.0, and its suppose to be 1.6-1.7

Here is my tune

I adjusted the Short pulse adder on this tune to a lower value initial value was twice the value in the tune.

I don't want someone to give me values, just some general info.

I know making the Offset tables smaller= leaner

And I believe decreasing the short pulse adder table = decreased IPW
(hence the lower values in the new tune)

Lastly with Fuel pressure, the IFR table (boost referenced) should be setup based off running idle pressure (mine is set to 50, and runs at 43 at idle)
Do I sit it up for 50 or 43?

Thanks for anyones help, just really stuck right now, can't tune the car till I get this corrected.

[Nitroused383]

Looks like you're running open loop speed density. Leave what you think is the correct injector values in there. You need to start tuning the idle regions of your VE table. Your injector PW will lower when you get the proper AFR dialed in at idle with your VE table. Unless I'm totally confused and you're saying you cannot get below 3.0 msec at all? I would be real careful going into boost on that VE table, might want to add 30% above 80 kpa to avoid going lean when you get into it. Better to start off rich than lean.

What do you mean yours is set to 50? What is set to 50? VE of around 60 in the idle regions has got to be pretty damn rich.

Also set your P0103 MAF High Freq fail to Mil on 1st error.

[robbyredneck]

it is what it is. your assuming that your injectors should respond the same way a ls1 setup should. maybe not. it's set fuel pressure: key on engine off, when it vacs it will pull it down, when you get to 105kpa it will be 50psi and when you go 210kpa you should have 65psi or so. are your injectors 60 lb/hr @ 3bar of fuel? i am going with nitrous on this . put the gb data back in and if you want to test your trimming use the scanner to command leaner, see if your ms go down, then if you want to get silly turn your fuel pressure up very small amounts at a time,put it in closed loop, and scan it to see if your injectors trim shorter. i know non of this seems very scientific but you will see the relationship rate between psi and time.

[Ben Charles]

Ok I need to play with the VE table then to adjust fuel so that plays into IPW( don't know why I overlooked that)

My rail pressure engine off is set to 50psi, but running idle its 43psi (vacumm I suppose) so I was wondering which should I set my IFR to?
Seems to run a lot better when IFR is 43psi=61.5 than 50psi=69.3

I changed the p103 to first MIL ( really don't know the difference between 2nd?)

are your injectors 60 lb/hr @ 3bar of fuel?

I am not sure to be honest, bought them from SpeedInc.

Thanks guys for the info, been real hot here but plan to mess with it soon.

I'll keep ya posted.

[Nitroused383]

That is the way a boost reference fuel pressure regulator works, when you're in vacuum you're fuel pressure will be lower than your base pressure (50lbs). Just like Robby explained. Set your Injector Flow Rate for what your injectors flow @ 50lbs.

Now this part I'm not 100% sure on, so if someone knows please correct me if I'm wrong. You should set your offset vs volts vs vac table the same as the 0 KPA column all the way across the entire table.

The VE table is your main fueling table you need to get that dialed in after you have the correct injector settings. Regardless of what injector flow rate settings work better it's only because your fueling table is not dialed in at all. You've been working at this backwards honestly. Try adjusting the VE table for fueling, if you run into problems where adjusting the values lower results in no changes than you need to play with your injector settings. If you're down to 20-30 in the idle regions and can adjust it all the way to 10 without change than you adjust injector info.

[Ben Charles]

Try adjusting the VE table for fueling, if you run into problems where adjusting the values lower results in no changes than you need to play with your injector settings.

I lowered my VE numbers in the idle cells, so hopefully fueling will be better. I have been going about this backwards, I have been worried about injector stuff and haven't even touched the VE table (since I have been messing with injector info anyway)

Also, plan to change the IFR table back to 69.X like before.

Thanks, Any info is welcome always learning.

[Ben Charles]

Ok put back in ALL correct 60lb data. Setup my IFR to 67.2=50psi rail.
Redone the VE table (lowering idle VE especially)

Car runs for a second and dies. Getting very aggrevating

Here is a log of it, and some reason it is measuring 95 map now????

Need HELP GUYS.

[robbyredneck]

be cool . when your car starts it's at 2.3 ms and 50 kpa. it will read atmosphere stalled. watch what the wideband is doing when it stalls and then add or subtract fuel accordingly. you may need to do some idle air work also

[Ben Charles]

Robby I had the idle air decently before, does that need to be redone? Didnt' even think of that, your right may need to play with it some and see.

Here is the tune from earlier tonight

[Ben Charles]

Well I started out adding 10% (X 1.10) to the Base running airflow (park/neutral) with no changes and the added an additional 15% with no changes.

With the VE table I lowered significantly, that didn't help either. On top of this my wideband about half way through its 20 second count down reads 6AE_? Tried to recalibrate it and it gives that code? But hp tuners says its still very rich (even after adjusting the VE table lower)

When the car was just sitting I decided to check Battery Voltage with the volt meter (it read 11.45 volts) I know its suppose to be around 14-14.5 running, but I don't know if thats a problem?

Here is this mornings tune.

[Nitroused383]

You RAF Base running airflow is really low try setting it to 1.32 for right now. Once you get it running you need to log IAC counts and possibly open your throttle body screw, make sure you reset your TPS sensor and are at 0% at idle. Also raise your idle rpm for now until you get it running right. Also what 2 bar map sensor are you using and what elevation are you at?

I've never seen anyone change the Injector bank select table, which I think is your injector firing order?? Might want to put that back to stock. Oh I almost forgot charge your battery up, I've seen weird things before like this where the car would start and die. The battery was too low and not allowing the MAF to fail to enable speed density.

[Ben Charles]

So instead of adding to my RAF I should decrease the values to 1.32 in the start up temps?? Or are you saying multiply by 1.32 adding an additional 32%?

When I had it running before the fuel pressure change it was running great with IAC counts in the 30-60's operating temps.

The injector bank select never has to be changed on LSX engines, but it has to be on LT1's. If not fuel trims are all over the place (postive on bank 1 and negative on bank 2)

I am in Northeast Arkansas by Memphis TN (close to sea level) and I am running and off brand AIP 2 bar map, but again it ran great before with it and read the same map as my GM unit at Idle.

Initially I had a the checkvalve installed backwards at the rail which caused the fuel not to return, and it ran great with the settings similiar to what I have now. I wanted to increase Fuel pressure to give the injectors a little more range. As soon as we did we removed the checkvalve (now a returnless system like it should be) and it dies instantly?
If I lie to the IFR table it will run, but I know thats not the right way to do things, sooooooo

[Nitroused383]

Are you viewing the tune in metric or imperial? It looked like your RAF in the running temp (111-198 degrees) was .9-.6 lb/min but if you're in metric that would be 7-5 g/sec which I would say should be 12-8 or so to get it dialed in. Doesn't matter too much though if you cannot even get it into those temps since it wont start I completely forgot you're running an LT1, neat setup there. Looked like your map sensor was reading around 95 kpa with the engine off, if you're at sea level I would say your map sensor offset is off a little bit. Try setting your offset to 8 instead of 10.3, see if this helps to get your kpa up to what it should be around sea level (99-100kpa?).

What fuel pressure are your 60lb injectors rated at?

[Ben Charles]

Nitrous we were just looking at it in two different formats, I changed the units, lol.
My 1 bar GM map read 101kpa before, so I adjusted the this map like you suggested, I will take a non running map to make sure its the same.

I have the 60lb Mototron injectors that speedinc sells, so I guess there setup for around 60 psi at 43.5, but I hear they are actually around 62.X at 43.5 hence my 67.2 rating at 50psi.
Part number: INJ60-8 Mototron 60# High Impedance Injectors

If I lower my IFR down close to 60 I can get the car to run. What does the computer think when I do this?? Could I just do this and modify the VE table to be correct as long as my IPW is low around 1.7??

[robbyredneck]

get your battery sorted out this can really mess stuff up. if you lower the ifr it puts more fuel in it. it sounds like you may be lean but you have tons of variables in the wind. there is a whole table dedicated to batt volts vs flow vs map . let alone what your fuel pressure is doing at low voltage. get the volts straight wideband good and the fuel pressure straight so you have a good baseline. then you can use scientific method.

[Nitroused383]

If the engine runs with your IFR table set to 60 it means your VE table is setup too lean. Actual flow should be set to 67.76 across the board for those injectors at 50psi and your offset table is not the correct values either. Multiply your VE in the idle regions by 12%. Looks like your cranking VE primary table is kind of low which isn't helping your starting issues. There are a few other tables that really help with starting, frictional airflow, startup airflow and several afterstart enrichment fueling tables. I've got a tune I want you to copy a few tables from. What is your email address?

[Ben Charles]

Thanks Nitrous I will change some things up then.

If the engine runs with your IFR table set to 60 it means your VE table is setup too lean.

Ok after thinking about it, that makes a little since (always learning)

Email is [email protected]

Thanks to you and Robby for helping me

Fixed the idle portion of the VE table by adding 12 percent
Changed IFR to 67.7 across
Changed the Offset table to the one in our other thread
Returned the Cranking VE table back to stock

[Nitroused383]

Sounds good, I hope it fires up and idles smooth for you. You may need a little higher VE values in the idle regions than what I am used to. It makes sense because your vacuum referenced FPR has lower fuel pressure @ idle regions. Think of the IFR table like this if it makes sense. A stock vehicle has 28-31 lb/hr IFR values, if you throw in a set of 60lbs the vehicle will probably not start at all because it's adding so much more fuel. Now you bump the IFR values up to what they are supposed to be and the computer compensates for the larger injectors. Vice versa if you had the stock injectors in with 60lb injector values. The car would be so lean it probably wouldn't even start.

[Ben Charles]

Vice versa if you had the stock injectors in with 60lb injector values. The car would be so lean it probably wouldn't even start.

Yep, I understand this now. If it doesn't start I will slowly add values to the idle VE until it runs and then go from there.

Do you still want me to try some of those other values? My email is a couple post back.

[Nitroused383]

Thats what makes the most sense to me atleast, with that analogy. The stuff I was going to email you was the right injector offset stuff and the VE Cranking table but I think you got that taken care of. In the other thread I was helping Brad out you can copy those others tables I posted but those are mainly for hot start issues, some of it helps with cold starting too though so it wouldn't hurt to copy those.

If you still can't get it to run you may want to crank up your RAF table until you get it dialed in, maybe around 15-20 g/sec (2-2.7 lb/min) in the 46-111 ECT cells. Also raising the idle rpm up a couple 100 more rpm will really help for now.