New tune..
07-01-2018, 07:38 AM
#1
Drifting
Thread Starter
New tune..
alittle about the car.. 04z 31,000 miles headers, vararam cai. Wires plugs fairly new and a mail order tune. brought the car for a street tune only changes. I must say a street tune is the way to go..but no complaints about a mail order. problem is now on a cold start it takes alittle longer to start..when before it would start immediately! After that its fine..i have a tech2 is there something i can fix with it? Thanks
07-01-2018, 06:09 PM
#2
Le Mans Master
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St. Jude Donor '12-'13-'14
alittle about the car.. 04z 31,000 miles headers, vararam cai. Wires plugs fairly new and a mail order tune. brought the car for a street tune only changes. I must say a street tune is the way to go..but no complaints about a mail order. problem is now on a cold start it takes alittle longer to start..when before it would start immediately! After that its fine..i have a tech2 is there something i can fix with it? Thanks
07-06-2018, 12:59 AM
#3
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St. Jude Donor '13-'14-'15
The Vararam and LT's will create fueling issues at cold start and even warm starts--
When your engine is 1st started the fueling is commanded by your "open loop table" Once the engine reaches 140* coolant temp it awitches to Closed loop After warmed it is switched by a timer rather than temperature to closed loop
Only a full tuner like HP or EFILIVE can correct the open loop fueling to make it start as before
PS the varraam is notorious for needing to add extra fuel in both open and closed loop fueling at P/T--as the added airflow makes your fueling lean and the ECM is constantly trying to add fuel
Not a big deal at P/T as the fuel trims are constantly adding fuel to achieve stoich of 14.68-1 HOWEVER IF you have a lean condition at P/T and the ECM is adding fuel---that % of extra fuel is also added to your WOT fueling as well as a lean safety---This makes your WOT fuel pig rich and lazy----Lean at P/T and starts and rich at WOT !!! A mess--
When your engine is 1st started the fueling is commanded by your "open loop table" Once the engine reaches 140* coolant temp it awitches to Closed loop After warmed it is switched by a timer rather than temperature to closed loop
Only a full tuner like HP or EFILIVE can correct the open loop fueling to make it start as before
PS the varraam is notorious for needing to add extra fuel in both open and closed loop fueling at P/T--as the added airflow makes your fueling lean and the ECM is constantly trying to add fuel
Not a big deal at P/T as the fuel trims are constantly adding fuel to achieve stoich of 14.68-1 HOWEVER IF you have a lean condition at P/T and the ECM is adding fuel---that % of extra fuel is also added to your WOT fueling as well as a lean safety---This makes your WOT fuel pig rich and lazy----Lean at P/T and starts and rich at WOT !!! A mess--
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04zjimc (07-31-2018)
07-12-2018, 03:00 PM
#4
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alittle about the car.. 04z 31,000 miles headers, vararam cai. Wires plugs fairly new and a mail order tune. brought the car for a street tune only changes. I must say a street tune is the way to go..but no complaints about a mail order. problem is now on a cold start it takes alittle longer to start..when before it would start immediately! After that its fine..i have a tech2 is there something i can fix with it? Thanks
07-31-2018, 09:31 PM
#5
Drifting
Thread Starter
The Vararam and LT's will create fueling issues at cold start and even warm starts--
When your engine is 1st started the fueling is commanded by your "open loop table" Once the engine reaches 140* coolant temp it awitches to Closed loop After warmed it is switched by a timer rather than temperature to closed loop
Only a full tuner like HP or EFILIVE can correct the open loop fueling to make it start as before
PS the varraam is notorious for needing to add extra fuel in both open and closed loop fueling at P/T--as the added airflow makes your fueling lean and the ECM is constantly trying to add fuel
Not a big deal at P/T as the fuel trims are constantly adding fuel to achieve stoich of 14.68-1 HOWEVER IF you have a lean condition at P/T and the ECM is adding fuel---that % of extra fuel is also added to your WOT fueling as well as a lean safety---This makes your WOT fuel pig rich and lazy----Lean at P/T and starts and rich at WOT !!! A mess--
When your engine is 1st started the fueling is commanded by your "open loop table" Once the engine reaches 140* coolant temp it awitches to Closed loop After warmed it is switched by a timer rather than temperature to closed loop
Only a full tuner like HP or EFILIVE can correct the open loop fueling to make it start as before
PS the varraam is notorious for needing to add extra fuel in both open and closed loop fueling at P/T--as the added airflow makes your fueling lean and the ECM is constantly trying to add fuel
Not a big deal at P/T as the fuel trims are constantly adding fuel to achieve stoich of 14.68-1 HOWEVER IF you have a lean condition at P/T and the ECM is adding fuel---that % of extra fuel is also added to your WOT fueling as well as a lean safety---This makes your WOT fuel pig rich and lazy----Lean at P/T and starts and rich at WOT !!! A mess--
07-31-2018, 09:33 PM
#6
Drifting
Thread Starter
Put a fuel pressure gauge on it and see if it is bleeding down overnight, sometimes the check valve or regualtors start to go bad. If you do not have a fuel pressure gauge try cycling the key a few times before starting, if it starts up normally then definitely have the fuel pressure checked. Your mods will not require start up tuning changes.
Last edited by 04zjimc; 08-02-2018 at 05:35 PM.
08-02-2018, 05:32 PM
#7
Drifting
Thread Starter
The Vararam and LT's will create fueling issues at cold start and even warm starts--
When your engine is 1st started the fueling is commanded by your "open loop table" Once the engine reaches 140* coolant temp it awitches to Closed loop After warmed it is switched by a timer rather than temperature to closed loop
Only a full tuner like HP or EFILIVE can correct the open loop fueling to make it start as before
PS the varraam is notorious for needing to add extra fuel in both open and closed loop fueling at P/T--as the added airflow makes your fueling lean and the ECM is constantly trying to add fuel
Not a big deal at P/T as the fuel trims are constantly adding fuel to achieve stoich of 14.68-1 HOWEVER IF you have a lean condition at P/T and the ECM is adding fuel---that % of extra fuel is also added to your WOT fueling as well as a lean safety---This makes your WOT fuel pig rich and lazy----Lean at P/T and starts and rich at WOT !!! A mess--
When your engine is 1st started the fueling is commanded by your "open loop table" Once the engine reaches 140* coolant temp it awitches to Closed loop After warmed it is switched by a timer rather than temperature to closed loop
Only a full tuner like HP or EFILIVE can correct the open loop fueling to make it start as before
PS the varraam is notorious for needing to add extra fuel in both open and closed loop fueling at P/T--as the added airflow makes your fueling lean and the ECM is constantly trying to add fuel
Not a big deal at P/T as the fuel trims are constantly adding fuel to achieve stoich of 14.68-1 HOWEVER IF you have a lean condition at P/T and the ECM is adding fuel---that % of extra fuel is also added to your WOT fueling as well as a lean safety---This makes your WOT fuel pig rich and lazy----Lean at P/T and starts and rich at WOT !!! A mess--
08-10-2018, 11:04 PM
#8
Safety Car
alittle about the car.. 04z 31,000 miles headers, vararam cai. Wires plugs fairly new and a mail order tune. brought the car for a street tune only changes. I must say a street tune is the way to go..but no complaints about a mail order. problem is now on a cold start it takes alittle longer to start..when before it would start immediately! After that its fine..i have a tech2 is there something i can fix with it? Thanks
08-11-2018, 07:57 AM
#9
Safety Car
What if they screwed up the timing a bit?
08-12-2018, 02:58 AM
#10
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St. Jude Donor '13-'14-'15
[QUOTE=tabbryour actuALuzz;1597771032]What if they screwed up the timing a bit?[/QUOTEny]
if he timing was too far advanced you would hear pinging under a load-- -However after your ECM hears too many "occurances of knock" it will slip into the low octane table as a safety precaution where the total timing may be about 1/2 of the timimg as the hi octane table---- this is complicated stuff Only data logging your actual final timing will help you sort out your "commanded timing VS your actual final timing" They should almost match less the timiming deducts for ECT AND IAT temp deductions
if he timing was too far advanced you would hear pinging under a load-- -However after your ECM hears too many "occurances of knock" it will slip into the low octane table as a safety precaution where the total timing may be about 1/2 of the timimg as the hi octane table---- this is complicated stuff Only data logging your actual final timing will help you sort out your "commanded timing VS your actual final timing" They should almost match less the timiming deducts for ECT AND IAT temp deductions
Last edited by tblu92; 09-04-2018 at 05:06 PM.
08-12-2018, 07:13 AM
#11
Drifting
Thread Starter
08-12-2018, 11:07 AM
#12
Drifting
Thread Starter
[QUOTE=tblu92;1597775671]
so for a example..I got this from hp tuners gm... which would I use to correct my cold start? Thanks
Click here to show toolbars of the Web Online Help System: show toolbars
GM > Engine > Fuel Control > Open & Closed
Open and Closed Loop
The VCM fueling generally operates in one of three modes: 1) Open loop, 2) Open loop STFT or 3) Closed Loop. Open loop is used when the O2 sensors are not warmed up, failed, or when an enrichment mode (such as power enrichment) is active. Open loop STFT is used on some PCM's when the O2 sensors are showing signs of operation (O2 Readiness), however the closed loop enable ECT has not been reached. In this mode the STFT's may function. The final mode is Closed Loop and in this mode the full closed loop fuel controller is operational.
This section allows controlling of the various base Equivalent Ratio's and AFR's when the VCM is running in openloop. It also allows control over the entry of the various modes described above.
Open Loop
What if they screwed up the timing a bit?[/QUOTEny]
if he timing was too far advanced you would hear pinging under a load-- -However after your ECM hears too many "occurances of knock" it will slip into the low octane table as a safety precaution where the total atiming may be about 1/2 of the timimg as the hi octane table this is complicated stuff Only data logging your actual final timing will help you sort out your "commanded timing VS your acyal final timing" They should almody match less the timiming deducts for ECT AND IAT temp deductions
if he timing was too far advanced you would hear pinging under a load-- -However after your ECM hears too many "occurances of knock" it will slip into the low octane table as a safety precaution where the total atiming may be about 1/2 of the timimg as the hi octane table this is complicated stuff Only data logging your actual final timing will help you sort out your "commanded timing VS your acyal final timing" They should almody match less the timiming deducts for ECT AND IAT temp deductions
Click here to show toolbars of the Web Online Help System: show toolbars
GM > Engine > Fuel Control > Open & ClosedOpen and Closed Loop
The VCM fueling generally operates in one of three modes: 1) Open loop, 2) Open loop STFT or 3) Closed Loop. Open loop is used when the O2 sensors are not warmed up, failed, or when an enrichment mode (such as power enrichment) is active. Open loop STFT is used on some PCM's when the O2 sensors are showing signs of operation (O2 Readiness), however the closed loop enable ECT has not been reached. In this mode the STFT's may function. The final mode is Closed Loop and in this mode the full closed loop fuel controller is operational.
This section allows controlling of the various base Equivalent Ratio's and AFR's when the VCM is running in openloop. It also allows control over the entry of the various modes described above.
Open Loop
- Open Loop F/A vs. Coolant Temp vs. MAP: This table is used to determine the commanded AFR when in open loop mode. It divides the Stoich AFR value. AFR is determined by 14.7/table value. Example: 14.7/1.30 = 11.3 AFR
- Open Loop F/A vs. Coolant Temp vs. MAP (Alcohol):Flexible Fuel Capable calibrations only. This table is used to determine the commanded AFR when in open loop mode. It divides the Stoich AFR value. If you make changes to the non alcohol table AFR, you must make the exact changes on this table as well. If not, then you will wind up with a difference between the two for your open loop AFR. AFR is determined by 14.7/table value. Example: 14.7/1.30 = 11.3 AFR
- Open Loop EQ Ratio Gas (Gear): This table is used to determine the commanded open loop equivalence ratio when running on gasoline and the transmission is in gear.
- Open Loop EQ Ratio Gas (P/N): This table is used to determine the commanded open loop equivalence ratio when running on gasoline and the transmission is in park or neutral.
- Open Loop EQ Ratio Alcohol (Gear): This table is used to determine the commanded open loop equivalence ratio when running on alcohol and the transmission is in gear.
- Open Loop EQ Ratio Alcohol (P/N): This table is used to determine the commanded open loop equivalence ratio when running on alcohol and the transmission is in park or neutral.
- Airflow Gain: This table is used to multiply the commanded open loop equivalence ratio based on airflow parameters.
- IVT Gain: This table is used to multiply the commanded open loop equivalence ratio based on intake valve temperature parameters.
- Injector Temp Gain: This table is used to multiply the commanded open loop equivalence ratio based on fuel injector temperature parameters.
- AIR Enrich: This table is used to multiply the Equivalence Ratio when in open loop mode when the AIR pump is on.
- AIR Gain: This table is used to multiply the Equivalence Ratio when in open loop mode when the AIR pump is on.
- AIR Airflow Gain: This table is used to multiply the Equivalence Ratio when in open loop mode when the AIR pump is on.
- Misfire EQ Ratio: Equivalence Ratio when in Cat protection mode due to misfire.
- EQ Ratio Minimum vs. ECT: This table is used to determine the minimum Equivalence Ratio when in open loop mode.
- TCS EQ Ratio Minimum: Minimum EQ Ratio when TCS is active.
- ETC Reduced Power EQ Ratio: EQ Ratio when ETC Reduced Power Mode is active.
- Closed Loop Blend Time: EQ Ratio will be blended from openloop to 1.0(stoich) over this amount of camshaft reference pulses.
- EQ Ratio Min: This table is used to define the lowest allowed commanded open loop equivalence ratio.
08-12-2018, 07:39 PM
#14
Safety Car
Mind if I ask who your mail order tune was from? I have a mail order tune from Diablew Tune using a Diablo inTune to load it. It has been nothing but great.
08-12-2018, 07:43 PM
#15
Drifting
Thread Starter