DFI Gen VII and Starting/Idle problems

[protosy]

i am about at my wits end with the gen vii that i have on my syclone (v8/twin turbo). i absolutely cannot get the thing to startup and idle without feathering the gas pedal and holding the pedal down a bit after starting it.

i have tried playing with the max's and min's in the iac tables, tried changing the target speed to increase it, etc... nothing seems to matter at all. its getting really frustrating.

to make things worse, i received a new calmap cable thats usb with the prokey in it and the stupid thing disconnects everytime the truck starts for more then 30 seconds. and wont reconnect until i power off the truck, close calmap, and start over again.



any help would be appreciated.

 

[quickt]

i am about at my wits end with the gen vii that i have on my syclone (v8/twin turbo). i absolutely cannot get the thing to startup and idle without feathering the gas pedal and holding the pedal down a bit after starting it.

i have tried playing with the max's and min's in the iac tables, tried changing the target speed to increase it, etc... nothing seems to matter at all. its getting really frustrating.

to make things worse, i received a new calmap cable thats usb with the prokey in it and the stupid thing disconnects everytime the truck starts for more then 30 seconds. and wont reconnect until i power off the truck, close calmap, and start over again.



any help would be appreciated.

USB cable just does not work call and complain. Warm up the engine. When you are idling adj. the throttle blade so that you have about 10-20% IAC position. You can find this on the idle configuration menu. Set the start up IAC position to 75-100% Check the start up fuel table. Sounds like you could be too rich. You can look in the diagnostic menu this will let you know what tables are affecting the start up. This is a real basic explanation. There are several tables to get this done. One of the things I really like about the gen 7 is the ability to get the car to start and idle hot or cold. It takes some work but after you understand its easy to do.

 

[turbobuick]

Disconnect the USB cable from the computer before you start the vehicle or try to make a datalog. The USB ports are powered and when you start the vehicle it kicks it off. Accel has problems with the new usb cable they are trying to sort out. Are you using an IAC on your TB?

 

[protosy]

thanks for the replies...

yes, i am using IAC on the motor...

what are the best fuel tables or areas i should be looking at to lean it out a bit for startup? i'll try playing with the things suggested in a bit to see if i can get to start and idle better

edit: well, no matter what i do i cannot get the laptop to connect while the truck is running, on the usb cable, which has my pro-key on it, so this is pretty much pointless. the only way i can connect is with a normal serial cable, which of course doesnt have the prokey.

 

[quickt]

cranking fuel, After start decay, After start fuel coefficent, starting rpm they have effect. some more than others. F1 key each table and do some reading. You can then see how the starting responds and you will know what table male changes to.

 

[protosy]

cranking fuel, After start decay, After start fuel coefficent, starting rpm they have effect. some more than others. F1 key each table and do some reading. You can then see how the starting responds and you will know what table male changes to.

thanks again for the input.

i think i finally figured out the "trick" to that stupid usb cable. when i get disconnected, unplug it and replug it into the laptop and hit f9 and try again... seems to work somewhat reliably; still a bit annoying and for any sort of tuning for steady state driving its going to be impractical, but i will manage for now.

the idle and startup are still killing me though. i adjust the throttle body to get it to have the iac around 15/20%... a few seconds later iac is at 75 with no change to the blades.... my only guess is that i am adjust the throttle body too early and am still in enrichment mode. and its PIG rich. bad, crazy bad. i will review those tables you mentioned above, maybe a few of them have crazy amounts of fuel in em.

 

[quickt]

Hit Crtl-D this will take you to the diag menu. You can view the active mode and enrichment mode you are using in real time. This will help you know where you are at during start up or when ever. Make sure the set you min IAC postion also dont forget the make sure you reset the TPS so the ecu knows when to go into idle mode. sorry took so long for response

 

[lcvette]

are you running the wideband setup with the gen 7?

If you want email me a .ecm file you are using for start up along with complete specs of your setup, CID, Cam, heads ported, etc etc and I will have a look at it and see if I can't get you somewhere closer to normal to start drivintg and tuning on the setup.

Chris

Lcvette1@aol.com

 

[protosy]

yup i am running the wb02 kit as well. i am mailing you the details..

thanks Chris

 

[lcvette]

Have you followed the advice above regarding the adjustment of the throttle blades to attain a 10-20% IAC duty cycle? this must be done before you try anything else.. air through the IAC isn't enough for that cube motor, it needs some gap on the throttle blades. give this a try.. from the looks of your file you look like you aren't running enough fuel in your idle VE areas.. mine ar in the .300 range..

are you still running the autocal wizard map? and what are your plans for the motor because I noticed you are not utilizing the scaled map axis which may help get some resolution around your idle area and definately going to help up around you desired boost level.

get me this information and I will see what I can do with your tune to get you going and starting and driving like normal to begin tweaking the WOT tune.

Chris

 

[protosy]

Have you followed the advice above regarding the adjustment of the throttle blades to attain a 10-20% IAC duty cycle? this must be done before you try anything else.. air through the IAC isn't enough for that cube motor, it needs some gap on the throttle blades. give this a try.. from the looks of your file you look like you aren't running enough fuel in your idle VE areas.. mine ar in the .300 range..

are you still running the autocal wizard map? and what are your plans for the motor because I noticed you are not utilizing the scaled map axis which may help get some resolution around your idle area and definately going to help up around you desired boost level.

get me this information and I will see what I can do with your tune to get you going and starting and driving like normal to begin tweaking the WOT tune.

Chris

Thanks for the reply. I've messed around, a ton, with the throttle blades and attempting to get the iac where it needs to be, but without much luck. I've cracked them open a bit, and it will eventually idle on its own, but only after it gets hot.

The idle areas of the VE are basically where there is 5% or so correction from the wbo2 to get to the target afr when warmed (no other corrections being applied). I agree that they are low, but the thing ran super rich with higher VE numbers.

The tune that I sent you isn't an autotune that Im aware of, its the base that was in the ecu when I got it, so im not sure of the origins.

 

[lcvette]

what will the operating parameters be as far as boost is concerned and what is the car idling at MAP wise (vacuum)? I can rework your scaled map axis to get you some better resolution. also what is your base fuel pressure with the vacuum/boost reference disconnected? and what fuel pump system are you running and what size return line. you have 160lb injectors which may require you to drop your fuel pressure to something like 30psi to be able to get some time for them to respond.. that size injectors doesn't like supershort pulsewidths. if your pressure is too high and the pulsewidths are as short as the injectors can be and maintain stability then you are out of control with VE numbers to go lower.. raising them you of course have more then enough.

hit me back and I will see what I can work up for ya since I have a little time to kill right now!

Chris

 

[protosy]

the motor idles around 10-12 inches of vacuum. fp at atmosphere is 45psi. the fuel pump is a weldon 2345a -12 feed -10 return.

i'd like to be able to tune for 12psi street and 28psi track tune. not sure if it works that way though

thanks again.

 

[lcvette]

first of all.. no way you'll be able to tune that thing down on 160's and 45psi base pressure with a pump that flows that volume.. you should have plenty of return line size to not over run the regulator so turn your fuel pressure down to about 31-32psi.. this is the drawback of larger injectors is their part throttle tuneability.

try this and see if you can now add some percentage to your VE table in the idle area. this should give you better response from the injectors and allow you some flexibility with pulsewidth to get it smoothed out.

as far as having two boost levels, that isn't a problem, but you will want to tune in your street tune first.. emphasizing resolution from 12-16psi on the map scale axis.. the boost rise from 0psi to your spring pressure happens so fast that it doesn't require alot of finesse here.. but once you attain boost peak you will want your resolution to say 1psi in the event it fluctuates up or down a bit throughtout each gear.

I will scale your map but I want you to adjust your fuel pressure first for your idle issue and then adjust your throttle blades to get her evened out at your desired RPM.. I would say this setup will be most comfortable idling around 1000-1100rpm with that cam to keep surging down and an AFR of around 13.5-13.9.

so decide on your desire idle speed try and set it using the throttle blade adjustment so that you are right around it with 10-20% duty cycle. this will help the IAC catch revs from falling too low (has plenty of room to let air in.. and additional 80% duty cycle. will help for decceleration and quick blips of the throttle in neutral.

I am gonna take a look at the rest of your tune right now but like I said.. that fuel pressure has got to come down unless you want a higher idle then normal.

Chris

 

[lcvette]

sent you back the file.. it was pretty far off.. this one will work decently if you can get the base VE where it needs to be at idle and then adjust the ENTIRE map so that your base VE at idle is in good shape. let me know when you are trying it out with your fuel pressure adjusted and I will help you get the map values adjusted to suit your starting VE!

Chris

 

[protosy]

sent you back the file.. it was pretty far off.. this one will work decently if you can get the base VE where it needs to be at idle and then adjust the ENTIRE map so that your base VE at idle is in good shape. let me know when you are trying it out with your fuel pressure adjusted and I will help you get the map values adjusted to suit your starting VE!

Chris

thanks, i havent received the file yet, but I will check again when i get home in a bit.