Light Throttle Hole
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Light Throttle Hole
Hey guys, Cruizing through a parking lot or just ever so lightly accelerating from a light, or just breathing on the throttle while cruising between 1500-2000rpm My 02 Lambda will drop like a rock, power loss is obviously occuring aswell, and I can immediately relieve this by closing the throttle and then pushing through it.. I can also sustain the problem and cause a major backfire, if I am too push into it instead of releasing.. So here is the setup.
this is a MAF setup, So dont reference advise from VE table information
1989 IROC
383 Stroker 030 10:1 est Compression
638 4Bolt block 6" throw clearanced
Mahle pistons, screw-capped
268XFI comp cam with 1.6 Magnum everything inc/ beehive
218 aluminum Heads
TPIS MINIRAM II
Edelbrock BBK 52mm.
30# accell
HEADMAN Shorty's
3" crossover Cat Back
MSD Coil and distributor (8366)
1227165 $6E ARAP base bin
Currently it idles rich in open loop, and rich on engaging throttle. however it idles much better there. I just changed out some leaking injectors causing a rich idle mixture.
I have a datalog of the deadspots driving.
this is a MAF setup, So dont reference advise from VE table information
1989 IROC
383 Stroker 030 10:1 est Compression
638 4Bolt block 6" throw clearanced
Mahle pistons, screw-capped
268XFI comp cam with 1.6 Magnum everything inc/ beehive
218 aluminum Heads
TPIS MINIRAM II
Edelbrock BBK 52mm.
30# accell
HEADMAN Shorty's
3" crossover Cat Back
MSD Coil and distributor (8366)
1227165 $6E ARAP base bin
Currently it idles rich in open loop, and rich on engaging throttle. however it idles much better there. I just changed out some leaking injectors causing a rich idle mixture.
I have a datalog of the deadspots driving.
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Re: Light Throttle Hole
Not sure what the Throttle Follower is, so im going to say no..
Im not apposed to trying the AE enrichment, lets figure that,
I dont move my throttle and
load is not changing and
rpm has no reason to change
and Im already RICH
It makes me think the computer is switching into double Fire mode, but my pulse width is well 1.5 or higher. so... sometimes this whole problem will manifest after three seconds and the more I drive around (20 minutes to 40minutes) It gets more irritating. ( also coolant and cylinder head are constant.
Im not apposed to trying the AE enrichment, lets figure that,
I dont move my throttle and
load is not changing and
rpm has no reason to change
and Im already RICH
It makes me think the computer is switching into double Fire mode, but my pulse width is well 1.5 or higher. so... sometimes this whole problem will manifest after three seconds and the more I drive around (20 minutes to 40minutes) It gets more irritating. ( also coolant and cylinder head are constant.
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Re: Light Throttle Hole
TF is when you open the T just a min amount the VAC drops and the A/F will then follow lean due to the fuel condensing out of atomization. To combat that the TF routine injects a very small amount of fuel. TF fuel can be adjusted in varying amount of usecs. TF fuel can occur without AE event. It is in the constants I recall(not tables).
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Re: Light Throttle Hole
Well After changing my $6E to the expanded one, I suddenly found all the entries I never knew about.
I incrementally changed the TF ( knowing it would probably not correct my issue, but does affectively do what you were saying ) and I was correct. Back to square one.
I incrementally changed the TF ( knowing it would probably not correct my issue, but does affectively do what you were saying ) and I was correct. Back to square one.
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Re: Light Throttle Hole
OK, Apparently thier are 5 points to adjustment.
The table I was looking at was wrong, I was suppose to edit the Throttle Follower Scalar, which is a linear default of 125/%of throttle. So rather then guess,,, Please chime and tell me a little more on the EXACT names of the scalars that need to be changed and anything else you care to share about them . Thanks Guys.
The table I was looking at was wrong, I was suppose to edit the Throttle Follower Scalar, which is a linear default of 125/%of throttle. So rather then guess,,, Please chime and tell me a little more on the EXACT names of the scalars that need to be changed and anything else you care to share about them . Thanks Guys.
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Re: Light Throttle Hole
I'm a little confused, in your first post you state that the O2 Lambda is dropping like a rock, as well as stating that this causes it to backfire and lose power. A low Lambda is rich, while a backfire is from being too lean (out the intake).
If the NB O2 voltage is dropping, that is lean. Lambda is > 1.
As for the TF, the code that Ronny is using has an AE adder as the IAC opens. I don't believe that the $6E code has this. TBI versus port injection.
Since the injectors are not stock you will likely need to tweak the injector compensation values. And may also need to change the injector PW's for entering and exiting single fire mode.
The 1.5 msec injector PW is border line on not opening enough to spray any fuel.
RBob.
If the NB O2 voltage is dropping, that is lean. Lambda is > 1.
As for the TF, the code that Ronny is using has an AE adder as the IAC opens. I don't believe that the $6E code has this. TBI versus port injection.
Since the injectors are not stock you will likely need to tweak the injector compensation values. And may also need to change the injector PW's for entering and exiting single fire mode.
The 1.5 msec injector PW is border line on not opening enough to spray any fuel.
RBob.
Last edited by RBob; 08-26-2012 at 05:32 PM.
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Re: Light Throttle Hole
Thanks Rbob. Sorry for the confusion..
1. Lambda and the narrow Band, indicate LEAN. The 'dropping' was just a reference to the Datalog.
2. Back fire occurs, only when both the event " the throttle hole " and you try to excellerate through it. ( You must back off the throttle and the problem resets and everything is normal.)
3. The Event only occurs between 1% and 10% throttle and under 2100 rpm.
4. As I have had this problem with ( 19lbs / 24lbs ) injectors , can I safely assume its not the Injectors Math that necessarily the issue ?
The theory behind the actual air density changing the state of Fuel from ( vapor to Liquid ) fits doesn't it ?
LV8 of 80-100 at idle ( under 800rpm )
1. Lambda and the narrow Band, indicate LEAN. The 'dropping' was just a reference to the Datalog.
2. Back fire occurs, only when both the event " the throttle hole " and you try to excellerate through it. ( You must back off the throttle and the problem resets and everything is normal.)
3. The Event only occurs between 1% and 10% throttle and under 2100 rpm.
4. As I have had this problem with ( 19lbs / 24lbs ) injectors , can I safely assume its not the Injectors Math that necessarily the issue ?
The theory behind the actual air density changing the state of Fuel from ( vapor to Liquid ) fits doesn't it ?
LV8 of 80-100 at idle ( under 800rpm )
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Re: Light Throttle Hole
Can you post the data log in a csv format? Always helps to see what the ECM is doing.
Have you adjusted the MAF tables?
RBob.
Have you adjusted the MAF tables?
RBob.
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Re: Light Throttle Hole
I have been through Maf table adjustments, I am pretty sure they were copied back to normal. I will give you a datalog as soon as I am home. Do you want me to post the text and a picture reference ( snap shot of the problem area ? )
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Re: Light Throttle Hole
RBob.
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Re: Light Throttle Hole
Sorry RBob for such a long delay.. I was in the middle of planning and getting married. Then had to re-install my laptop.
Attached is a Zip containing the Datalog and a picture of the suspected area.
After driving the car around for a while,
I noticed that the light throttle problem only exists under 2000 RPM..
Also found the module in the prop billet MSD distributor is Junk.. So I bought and replaced it with a after market ACCEL one and Hey,, all is well.
except the problem were still working on.
Attached is a Zip containing the Datalog and a picture of the suspected area.
After driving the car around for a while,
I noticed that the light throttle problem only exists under 2000 RPM..
Also found the module in the prop billet MSD distributor is Junk.. So I bought and replaced it with a after market ACCEL one and Hey,, all is well.
except the problem were still working on.
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Re: Light Throttle Hole
Further Review.
Maf raw signal does not change but the calculated MAF Value does..
Injector pulse and LV8 both take a similar dive.
Cross overs during event goto an even number just under 100 and stay pretty constant..
This leads me to believe the Problem is not Fuel Vapor cendensing anymore, and more like a Calculated mishap..
Maf raw signal does not change but the calculated MAF Value does..
Injector pulse and LV8 both take a similar dive.
Cross overs during event goto an even number just under 100 and stay pretty constant..
This leads me to believe the Problem is not Fuel Vapor cendensing anymore, and more like a Calculated mishap..
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Re: Light Throttle Hole
The issue is that the ECM thinks that the MAF is bad and is going into n-alpha mode. Which isn't calibrated correctly for a 383.
{edit: this following statement is why the ECM thinks that the MAF is bad:}
The airflow is too high for the RPM & TPS% {end explanation}
Increase the airflow threshold at this location (55 should do it):
It also wouldn't hurt to get the default MAF calculation closer so that if/when the MAF does fail the vehicle is still drive-able.
RBob.
{edit: this following statement is why the ECM thinks that the MAF is bad:}
The airflow is too high for the RPM & TPS% {end explanation}
Increase the airflow threshold at this location (55 should do it):
Code:
LC210 FCB 45 ; If Air Flow <= 45 gms/sec, disable ERR #33
RBob.
Last edited by RBob; 11-07-2012 at 05:09 PM. Reason: edit to better explain what is occurring
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Re: Light Throttle Hole
As far changing the MAF calculation closer .. I agree this should be "mapped" better to what the car is capable of reading. Are you not referring to the MAF TABLES ?
Wouldn't the SES light come one during this event ? as it is now the O2 lean will come on only and ONLY after a select amount of time during its Bogging moment..
Last edited by Hrock; 11-07-2012 at 05:03 PM.
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Re: Light Throttle Hole
Code:
LC21E FCB 167 ; If TPS > 65.2%, then use for MAF Default ; CALIB = Arg * 2.56 ; LC21F FCB 21 ; Gms/sec Scale factor ; gms/sec/IAC Count ; CALIB = Arg * 256 ; LC220 FDB 1024 ; 4 Gms/Sec default air flow offset ; CALIB = Arg * 256 ;-------------------------------------------------- ; Default air flow offset per pct TPS vs RPM ; Value = Gms/Sec * 100 pct, (Offset) ; ; CAL = Arg * 100 ;-------------------------------------------------- LC222: FCB 8 ; 9 LINE TBL ;------------------------------------------------- ; ; Gms/Sec RPM ;------------------------------------------------- LC223 FCB 30 ; 0.30 400 LC224 FCB 90 ; 0.90 800 LC225 FCB 110 ; 1.10 1200 LC226 FCB 135 ; 1.35 1600 LC227 FCB 150 ; 1.50 2000 LC228 FCB 175 ; 1.75 2400 LC229 FCB 210 ; 2.10 3200 LC22A FCB 225 ; 2.25 4000 LC22B FCB 230 ; 2.30 4800
Although, I don't know if they are from unplugging a sensor or not.
RBob.
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Re: Light Throttle Hole
Problem solved.
Connectors were not unplugged, but a Throttle recalibration was necessary, I imagine that is why TPS was showing up..
Prom error is from the APU1 loosing its flash when running the RT mode. Simple and Quick update from Tunerpro, and it runs again.
So I assume dynamic is your company ?
Connectors were not unplugged, but a Throttle recalibration was necessary, I imagine that is why TPS was showing up..
Prom error is from the APU1 loosing its flash when running the RT mode. Simple and Quick update from Tunerpro, and it runs again.
So I assume dynamic is your company ?
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Re: Light Throttle Hole
Well Bob, I very much appreciate everything you have done to help. Thank you . Im always looking for new ideas , So I was thinking, the best way to say thanks was to buy something.. This 7165 ECM I have been wondering why it has such a problem with Data communication. ? Do you have a HUD for replacing my setup, while staying in the 7165 format ( no serious deviation from stock wiring. )
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Re: Light Throttle Hole
Well Bob, I very much appreciate everything you have done to help. Thank you . Im always looking for new ideas , So I was thinking, the best way to say thanks was to buy something.. This 7165 ECM I have been wondering why it has such a problem with Data communication. ? Do you have a HUD for replacing my setup, while staying in the 7165 format ( no serious deviation from stock wiring. )
Can email or PM me for the re-pin guide. This is just moving fewer then a handful of the terminals/wires in the ECM harness connectors. The former MAF wires are used for the MAP sensor.
RBob.
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Re: Light Throttle Hole
Taking a longer look at MAF defaults I figured I should either Force n-alpha with very restricted values, or Unplug the sensor and tune for Best AF.. Im wondering If Ican insert code to add more lines of RPM defaults, The gofor 400 rpm increments then part way jump to 800 increments. Obviously ending at 4800, and my engine breathes well in the 6500rpm range.
So Can you Add more resolution to the Defaults RPM ( or any Part of the code ? )
Are the limitations strictly just what ever the ROM can hold, or do the address's have HAL Restrictions. Does the kernel make Calls to specific regions, or can you remap the Prom to expand certain areas..
I have background on Machine code for PIC and Z80 from the 80's LOL..
So Can you Add more resolution to the Defaults RPM ( or any Part of the code ? )
Are the limitations strictly just what ever the ROM can hold, or do the address's have HAL Restrictions. Does the kernel make Calls to specific regions, or can you remap the Prom to expand certain areas..
I have background on Machine code for PIC and Z80 from the 80's LOL..
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Re: Light Throttle Hole
You can mod the code, no issues with doing that. It is a flat address space, stock is from $C000 through $FFFF. Need to move that table to another location so additional rows can be added to it. Also change the code that calls the table look up routine so the proper RPM increment & number of rows is used.
When I started to modify the code I did patch files. That is a small piece of assembly that created a S19 file. Then applied that patch to the BIN via a utility program (it is posted here as S19_PAT.EXE, see the tuning guide book sticky for an intro to patching code).
Eventually changed the dis-assembly so that it could be assembled. And changed all absolute addresses to labels so that things could be moved around without breaking the code.
Not sure how much room is left over in the stock code space. Can likely use the address space from $8000 through $BFFF (with a '256 or '512 PROM). Test this first to make sure that the '7165 ECM decodes that address area and does a ~CS on the PROM.
RBob.
When I started to modify the code I did patch files. That is a small piece of assembly that created a S19 file. Then applied that patch to the BIN via a utility program (it is posted here as S19_PAT.EXE, see the tuning guide book sticky for an intro to patching code).
Eventually changed the dis-assembly so that it could be assembled. And changed all absolute addresses to labels so that things could be moved around without breaking the code.
Not sure how much room is left over in the stock code space. Can likely use the address space from $8000 through $BFFF (with a '256 or '512 PROM). Test this first to make sure that the '7165 ECM decodes that address area and does a ~CS on the PROM.
RBob.
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