Code 32 (EGR Malfunction) Diagnosis
Thread Starter
Drifting
Joined: Jul 2014
Posts: 1,426
Likes: 46
From: Lynchburg, VA
Code 32 (EGR Malfunction) Diagnosis
I'm working on tuning my 90's ECM, but I've been getting CEL code 32, indicating a problem with the EGR system.
Both runs I've gone on, the light comes on at around the same spot. 15-20 minutes in, I turn onto the first street that doesn't have a lot of stop signs, so it's the first stretch I cruise at a constant speed for a while. Maybe a half mile onto that road, the light comes on. The second run, a few detours made it take 10 minutes longer getting to that road, so I believe the determining parameters are RPM and load rather than time running.
I haven't done any testing yet, but I noticed something worth looking into in the BIN.
I saw that in the tune file I'm working off of, the "EGR % Duty Cycle Vs. Vacuum Vs. RPM" table consists of 99.61 in each cell except for the first row and last column (800 RPM and 0 kPa, respectively), which contain 0. In contrast, the original tune looked a bit different, with the numbers decreasing from 99.61 as vacuum increased and as RPM decreased (the first row and last column are still 0, except 1200 RPM 80 kPa contains 25.00).
That's a pretty significant difference in the cell I cruise in - at 1600 RPM, 70 kPa vacuum (which equals 30 kPa absolute pressure, as displayed in VE tables), the two BINs differ by about 70%.
Do you guys know why the guy who gave me the initial tune file would have changed this, and could this have something to do with my issues?
EDIT:
Two more pieces of information. My BLMs are telling me I have a volumetric efficiency of over 100% in several places (which is doubtful), which seems like it could be related to this issue. Also, when I put a hose over the EGR valve vacuum inlet, I can hear the valve clunk when I apply only light suction. I tried this with the engine running to see if the engine bogged down like it's supposed to, and strangely the valve no longer held the vacuum I applied.
Both runs I've gone on, the light comes on at around the same spot. 15-20 minutes in, I turn onto the first street that doesn't have a lot of stop signs, so it's the first stretch I cruise at a constant speed for a while. Maybe a half mile onto that road, the light comes on. The second run, a few detours made it take 10 minutes longer getting to that road, so I believe the determining parameters are RPM and load rather than time running.
I haven't done any testing yet, but I noticed something worth looking into in the BIN.
I saw that in the tune file I'm working off of, the "EGR % Duty Cycle Vs. Vacuum Vs. RPM" table consists of 99.61 in each cell except for the first row and last column (800 RPM and 0 kPa, respectively), which contain 0. In contrast, the original tune looked a bit different, with the numbers decreasing from 99.61 as vacuum increased and as RPM decreased (the first row and last column are still 0, except 1200 RPM 80 kPa contains 25.00).
That's a pretty significant difference in the cell I cruise in - at 1600 RPM, 70 kPa vacuum (which equals 30 kPa absolute pressure, as displayed in VE tables), the two BINs differ by about 70%.
Do you guys know why the guy who gave me the initial tune file would have changed this, and could this have something to do with my issues?
EDIT:
Two more pieces of information. My BLMs are telling me I have a volumetric efficiency of over 100% in several places (which is doubtful), which seems like it could be related to this issue. Also, when I put a hose over the EGR valve vacuum inlet, I can hear the valve clunk when I apply only light suction. I tried this with the engine running to see if the engine bogged down like it's supposed to, and strangely the valve no longer held the vacuum I applied.
Last edited by C4ProjectCar; May 25, 2017 at 03:17 PM.
Racer
Joined: Feb 2004
Posts: 427
Likes: 86
From: Rockwall TX
Treat it as an EGR issue as those are the typical driving conditions... valve, solenoid, vac tubes. There's no egr temp sensor on 90 instead the o2 sensor monitors the exhaust and flags 32 if no change when expected.
Not sure on that bin, I haven't crossed that bridge yet, but possible tuner attempting to disable EGR?? only a guess obviously didn't work, but anyway imo disable is the real fix for 32
Not sure on that bin, I haven't crossed that bridge yet, but possible tuner attempting to disable EGR?? only a guess obviously didn't work, but anyway imo disable is the real fix for 32
Thread Starter
Drifting
Joined: Jul 2014
Posts: 1,426
Likes: 46
From: Lynchburg, VA
Figured it out, just had a bad EGR valve. In all a pretty easy fix.
As far as disabling EGR goes, I disagree. EGR gives better mileage (who doesn't want to save money on gas?) and reduces emissions (legally-required in CA, and who wants to see and breathe smog?), and since it doesn't add any exhaust gas at WOT the realistic effect on power is negligible to nonexistent.
As far as disabling EGR goes, I disagree. EGR gives better mileage (who doesn't want to save money on gas?) and reduces emissions (legally-required in CA, and who wants to see and breathe smog?), and since it doesn't add any exhaust gas at WOT the realistic effect on power is negligible to nonexistent.
