Hesitation 2-3.5k rpm part throttle
#41
Registered User
Just to update.
Cleaned MAP sensor with MAF cleaner 3 times. Saw some black residue come out during the 1st iteration but none during the 2nd and 3rd. No change. Makes sense as my MAP readings in the datalogs are stable and not intermittently dropping. Same with TPS.
Ran two bottles of Chevron Techron thru 24 gallons of fuel. No change.
Installed a new Fuel Pulsation Damper even though the old one seemed to move the set screw up and down. Thought maybe the spring got weak over the course of 90K miles and maybe wasn't reacting as intended. No change in datalogs.
I also checked cam timing. Looks spot on. Again, no change.
If there was a properly functioning DBW AP2 nearby, I'd like to try swapping fuel injectors.
This following thread make it seem like it's the APP sensor. Multiple guys there are reporting similar symptoms with no CEL.
http://www.tsxclub.com/forums/1st-ge...acement-3.html
If the APP sensor was intermittently bad, then should I not see it in the datalogs? And it still doesn't explain the lean AFR spike. The ECU controls the throttle plate so if the APP did suddenly read low, it would reduce throttle angle accordingly but should still maintain proper AFRs. So one would experience the same symptoms but without the obvious lean AFR spike.
Cleaned MAP sensor with MAF cleaner 3 times. Saw some black residue come out during the 1st iteration but none during the 2nd and 3rd. No change. Makes sense as my MAP readings in the datalogs are stable and not intermittently dropping. Same with TPS.
Ran two bottles of Chevron Techron thru 24 gallons of fuel. No change.
Installed a new Fuel Pulsation Damper even though the old one seemed to move the set screw up and down. Thought maybe the spring got weak over the course of 90K miles and maybe wasn't reacting as intended. No change in datalogs.
I also checked cam timing. Looks spot on. Again, no change.
If there was a properly functioning DBW AP2 nearby, I'd like to try swapping fuel injectors.
This following thread make it seem like it's the APP sensor. Multiple guys there are reporting similar symptoms with no CEL.
http://www.tsxclub.com/forums/1st-ge...acement-3.html
If the APP sensor was intermittently bad, then should I not see it in the datalogs? And it still doesn't explain the lean AFR spike. The ECU controls the throttle plate so if the APP did suddenly read low, it would reduce throttle angle accordingly but should still maintain proper AFRs. So one would experience the same symptoms but without the obvious lean AFR spike.
#42
Sorry to resurrect my old post but I wanted to try and fix this issue one last time before I sold the car. I bought a new MAP sensor and installed it without resetting the ECU. It seemed to work great for about a week then it came back. The hesitation is a bit different but there none the less. I datalogged it and am trying to post a picture of it but having a hard time. [img][/img] It goes red to where i'm pointing the cursor. I really don't have much idea on what this means but can someone please chime in. Also i'm not sure on how to show all the graphs, theres a drop down that lets me choose so I chose AFR graph.
#44
How's your battery?
#46
Passed a load test?
#47
Installed the new air-fuel sensor. No change. I was re-reading this post and s2ki member Gernby seemed to be on the right track. "It sounds like the issue you are referring to is actually just the OEM ignition and knock tables. At high load, the stock tune (and I believe all Hondata canned tunes) will retard ignition timing a LOT around 2500 RPMs. This causes a pronounced "surge" in torque at about 3K RPMs. If you remove the dip at 2500 RPMs from the knock ignition limit table, that surge will go away." Does anyone have a Flashpro map with this issue tuned out that I could upload to my vehicle? Also I have a 06+ OEM denso O2 sensor (air-fuel sensor) with 9500 miles on it for sale ;-)
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senor_flojo
Texas - Central Texas S2000 Owners
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01-28-2012 07:17 AM