WTF?!?!? WOT is closed loop?!?!?
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WTF?!?!? WOT is closed loop?!?!?
Can anyone point me in the right direction on this? I haven't made changes that should affect this - just the Nogo big cam idle stuff and IFR table for SVO injectors - but when I mash the throttle I get about 1 second (9 samples with EFIlive) of openloop and power enrichment, and then it goes closed loop and 14.7 AFR. I have checked these obvious things:
TP 100%
Cell 22
ECT 185
IAT 91
COT off
WOT enable 65% TP, 142* (F I assume)
MAP 98-99kPa
Where do I look next?
TIA
TP 100%
Cell 22
ECT 185
IAT 91
COT off
WOT enable 65% TP, 142* (F I assume)
MAP 98-99kPa
Where do I look next?
TIA
Last edited by critter; 07-13-2004 at 02:46 PM.
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Originally Posted by Brains
Fuel trim cell 22 is WOT/PE..
#4
I'll take a shot at it.........Canister Purge is activated. Drops it back to EQ ratio =1.00= 14.7 and closed loop. Scan to see if your Fuel System Purge is active - I'm not sure what the PID is??? Sound plausible? Refer to 2nd page this thread for more info....->
http://www.efilive.com/forum/viewtopic.php?t=474
http://www.efilive.com/forum/viewtopic.php?t=474
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Originally Posted by Bink
I'll take a shot at it.........Canister Purge is activated. Drops it back to EQ ratio =1.00= 14.7 and closed loop. Scan to see if your Fuel System Purge is active - I'm not sure what the PID is??? Sound plausible? Refer to 2nd page this thread for more info....->
http://www.efilive.com/forum/viewtopic.php?t=474
http://www.efilive.com/forum/viewtopic.php?t=474
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Originally Posted by Bink
I'll take a shot at it.........Canister Purge is activated. Drops it back to EQ ratio =1.00= 14.7 and closed loop. Scan to see if your Fuel System Purge is active - I'm not sure what the PID is??? Sound plausible? Refer to 2nd page this thread for more info....->
http://www.efilive.com/forum/viewtopic.php?t=474
http://www.efilive.com/forum/viewtopic.php?t=474
At TP=85%, it switches from CL to OL-DRIVE. Cell is still 15, EQ=1.0, and EVAPDC=90%. Next sample, TP goes to 100%, EQ goes to 1.25 and EVAPDC to 18%. Next sample, EVAPDC goes to 6%. Next sample, cell goes to 22 and EVAPDC goes to 0. Next 7 samples are the same. Next sample, PCM goes to CL, EQ to 1.0. It stayed in CL about 1.7 sec. Next 12 samples the same. Lifted foot. Next sample TP goes to 0. Next sample, cell goes to 3 and EVAPDC goes to 11%. This is really wierd ...
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Originally Posted by critter
Wow ... nobody has an idea?
Last edited by gojo; 07-15-2004 at 10:37 AM.
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Originally Posted by gojo
How about raising Closed Loop enable temp to some high value. If it the stays in open loop you might have incorrect ECT being reported?
#10
Power enrich mode will not turn on until all of the qualifications are met.
There is also a timer to hold off PE.
Enable Map
% TPS Enable
Delay mode RPM (Rpm > to bypass the delay)
Ken
There is also a timer to hold off PE.
Enable Map
% TPS Enable
Delay mode RPM (Rpm > to bypass the delay)
Ken
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Originally Posted by Super Sport X2
Power enrich mode will not turn on until all of the qualifications are met.
There is also a timer to hold off PE.
Enable Map
% TPS Enable
Delay mode RPM (Rpm > to bypass the delay)
Ken
There is also a timer to hold off PE.
Enable Map
% TPS Enable
Delay mode RPM (Rpm > to bypass the delay)
Ken
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Here is another clue:
I can go OL-DRIVE with PE as long as I don't use 100% TP. I have gone as high as 90% TP and as long as 9 seconds in OL-DRIVE/PE but when I go 100% TP, it drops back to closed loop after a second or so.
I also have seen this error, but I don't know when it happens in relation to my test runs but it did not happen on my most recent test:
P0123 "Throttle/Pedal Position Sensor/Switch A Circuit High Input"
So, is my throttle blade opening too far and sending too high a voltage to the PCM, causing it to kick out of OL/PE mode? I haven't checked yet since I am not home, but will check later. I don't know what the max TP sensor output is supposed to be, or that to do with it if it is too high.
I can go OL-DRIVE with PE as long as I don't use 100% TP. I have gone as high as 90% TP and as long as 9 seconds in OL-DRIVE/PE but when I go 100% TP, it drops back to closed loop after a second or so.
I also have seen this error, but I don't know when it happens in relation to my test runs but it did not happen on my most recent test:
P0123 "Throttle/Pedal Position Sensor/Switch A Circuit High Input"
So, is my throttle blade opening too far and sending too high a voltage to the PCM, causing it to kick out of OL/PE mode? I haven't checked yet since I am not home, but will check later. I don't know what the max TP sensor output is supposed to be, or that to do with it if it is too high.
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Well, I found it. I'll report here in case anyone else ever runs into this.
The problem was the sum of several things, but the result was that the PCM was seeing 4.9V at WOT. The manual says it is supposed to be 0.5V to 4.5V and over 4.75V is an error code - P0123. That explains the periodic P0123 code I would get, but strangely enough, I would not get it every time I ran a WOT test. This is probably because the condition did not last the required 10 seconds. However, within a second or so after the PCM saw 4.9V it would kick out of OL/PE mode and back into CL and shoot for stoich. This is counter intuitive to me. I would think if the TP sensor is in trouble you would want to go open loop and keep it rich, but what do I know ...
The reason the PCM was seeing 4.9V was because the throttle blade was going over center a bit. I have a ported TB with the throttle stop mod, and either the set screw backed out or the 2000 cable pulley is a bit different than the 1999 on I had on before. Perhaps there is a bit of difference between the TP sensors. Rather than keep the throttle blade from opening all the way, I slotted the TP sensor bolt holes and adjusted it so that the range was 0.5V to 4.5V, throttle closed to full open. Now my Z28 is a happy camper and I can finally start tuning.
The problem was the sum of several things, but the result was that the PCM was seeing 4.9V at WOT. The manual says it is supposed to be 0.5V to 4.5V and over 4.75V is an error code - P0123. That explains the periodic P0123 code I would get, but strangely enough, I would not get it every time I ran a WOT test. This is probably because the condition did not last the required 10 seconds. However, within a second or so after the PCM saw 4.9V it would kick out of OL/PE mode and back into CL and shoot for stoich. This is counter intuitive to me. I would think if the TP sensor is in trouble you would want to go open loop and keep it rich, but what do I know ...
The reason the PCM was seeing 4.9V was because the throttle blade was going over center a bit. I have a ported TB with the throttle stop mod, and either the set screw backed out or the 2000 cable pulley is a bit different than the 1999 on I had on before. Perhaps there is a bit of difference between the TP sensors. Rather than keep the throttle blade from opening all the way, I slotted the TP sensor bolt holes and adjusted it so that the range was 0.5V to 4.5V, throttle closed to full open. Now my Z28 is a happy camper and I can finally start tuning.
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Originally Posted by Super Sport X2
Excellent post critter.
I had no idea you were running a modified throttle or getting
error codes in the WOT process.
Ken
I had no idea you were running a modified throttle or getting
error codes in the WOT process.
Ken
WOT, 6500, and the PCM is trying to achieve stoich ... thank God for knock retard.
But the bigger lesson is that anyone who has the throttle stop mod on their ported TB would be advised to check the TB sensor voltage PID.
#18
This brings up an interestign question for me. Is there a way I can force the PCM to run in closed loop 14.7 all the time? That would really make my life easier. I can program my LM-1 ( & AuxBox ) to simulate 14.7AFR at any actualy AFR as read by the wideband. So, under load, I could have the LM-1 output a 14.7 signal when the acutal AFR is 12.5, etc. Then, theoretically, instead of fighting the PCM, it would be tricked into doing my biding