natec

Does anyone know how to fix a code 32 (egr problem). I Have tryed just about everything. I Have got a led installed to the back of the connector that connects to the egr solenoid and the signal ( duty cycle)seems to be working find. I have ohmed out the solenoid ( 26.4 ) and seems to be Ok. I also have a vacuum guage teed in the egr line and when the led goes out ( no ground to the solenoid from the ecm) I have around 10-15 inches of vacuum on the egr side of the vacuum line. I can monitor this inside the car while driving because I have the Led mounted inside the car ( 1990 corvette ) and the vacuum gauge mounted on the windshield. I get the code 32 while cruising on the highway around 55 to 70m miles per hour. I have also noticed that the ecm sends a ground signal (led comes on)around 15 to 30 seconds before the code 32 appears. I figure that the ecm is testing the egr system when is happening but dont know for sure. Also the vucuum goes completely away when the led comes on as it should or at least from what I have read. THe park/ nuetral switch also seems to be working correctly because the led is on in park and neutral and no vacuum is being applyed (EGR solenoid is normally open and closes when ground is applyed by the ecm). The duty cycle (ground from the ecm) starts to occur after the motor starts to warm up a little and in drive around 1500 rpms. This seems to be correct from what I have read. I have a 1990 corvette service manual. I have tryed 4 different ecms,three egr solenoids( these are hard to come because of being discontinued),two egr valves , three oxegen sensors,three different map sensors, two tps switches, two IAC stepper motors, two different MAP sensors. I have removed the pleutum and the egr valve and cleaned all the egr passages on intake side and the exhaust side all the away down to the exhaust manifold to the egr valve. I also am running a lap top with software ( 3 different versions,tuner pro RTEF live,data master,C.A.T.S. tuner, ) to monitor this. I have found a good way to make sure the passage ways are clean if anyone is interested using a set of ear plugs on a string and then blowing the plug through the passages then tape a larger diameter rope to the end and then pull it through. Works great. I have bought an adapter chip that removes the egr function but this is a band aid on not the right fix. I just cant stand looking at that SES light. Any help would be appreciated. Thanks

toptechx6

If you have installed a free flowing exhaust system check out this link, especially paragraph #5.

http://www.asashop.org/autoinc/dec97/egr.htm

natec

No, I havent installed a free flow exhaust.But I did install a after market cat. convertor. The problem started after I had injector problems. I installed new accel brand 24lb injectors. This fixed the running problem. Maybe I should have installed the 21 lb versions.

C4boy

Does the '91 still use an EGR temperature sensor (mounted near the distributor)? They're pretty common for breaking and throwing a code 32.

natec

No, There is no egr temp switch. This is a speed density (map sensor) system. I believe the temp switch was through 1989.

GKK

I know the L98 engine can run with #24 injectors but, you should have bought the #22 Bosch III's from supporting member FIC (Fuel Injector Connection) which are the correct ones for the L98.

Accel injectors have had a bad reputation for reliability and leakage.

Your engine might be running a little rich which will eventually ruin the new Catalytic converter.

Have a Quality Reputable repair shop "Properly" diagnose the problem which will save you a lot of Time, Money and Frustration.

QCVette

I had an 88 with a code 32 problem. I tried checking all of the things I could and even tried a bypass wiring to defeat the light.

I replaced the EGR and still had the same problem. I checked it and the vacuum diaphram wouldn't hold a vacuum. This was on a new part. I tried another one at the store and it was bad also.

I finally bought an AC part from Rock Auto and it worked fine. Problem solved.

Good luck.

natec

My Egr seems to be holding vacuum fine using a vacuum pump. Then when the motor is cranked over the vacuum goes to zero as it should because of being a negtive pressure type EGR valve. I have been able to defeaft the light also by coding out this fault using a special adapter used on the prom.

GKK

Edit: The 85-87 L98's used a Positive Back Pressure EGR valve.

Too, check a Positive Back Pressure EGR valve:

Start engine and Hold to 2000 rpm.
Apply Vacuum to the EGR valve.
The engine RPM should drop by 100 rpm.

My 91 L98 had a code 32. I checked everything related (EGR Solenoid, EGR Valve, Vacuum leaks...) and everything checked out fine.

I finally just replaced the EGR valve with an AC Delco EGR valve and the code 32 went away.

gmboileau

I believe that 1990 uses a negative pressure EGR valve.

SunCr

Go back to your Shop Manual so you can see what the trigger is: Voltage rise/drop when the ECM drives the Solenoid or BLM's? If BLM's, it'll swing rich if it gets Oxygen instead of exhaust and when the O2 responds, the extra fuel sets the code. Monitor, data log fuel trim before and after the event/check vacuum lines, routing, etc.

natec

Thanks SunCr ,I will give it a try. I will also monitor this with my software/ laptop. Thanks

gmboileau

I understand that the ECM monitors the MAP voltage to determine if an EGR request was successful or not. When the EGR is turned on, engine vacuum will lower a little and the Map voltage should increase. The ECM looks for that increase as a test that there was exhaust gas flow at the EGR valve.

The ECM will throw a code 32 if it suspects that the EGR request was not successful.

Monitoring the map voltage with Tuner Pro or the like (Circuit 432 LT GRN connector B on the Map sensor) and the Vacuum value at the Map sensor when the EGR is supposed to be on could be useful to determine if there is actually flow at the EGR valve.

Since the MAP sensor is the feedback device to the ECM for EGR flow making sure that there no vacuum leaks or bad connections at the MAP sensor is important.

natec

I do see the map vacuum drop a little when the the egr duty cycle is at 100%.

gmboileau

Seeing the vacuum drop implies the EGR is opening and allowing exhaust gas into the mixture..... that seems to indicate the EGR circuit is working.
Can you see a corresponding increase in MAP voltage?

natec

Yes tuner pro rt (software) show on the monitoring graph as the vacuum increases the volage increases as well. Sorry I took so long getting back to you I have been out of town.