CEL 32 BUT EGR VALVE WORKS

[kendem]

I was getting codes 32(erg) and 34(knock sensor). When I test my EGR vale with engine running the valve lifts up just fine at 2000+ rpms. After reading the FSM, it looks like code 32 could be caused by too rich fuel mixture as a response from the O2 sensor.

So my question is when you manually lift the EGR valve should the engine stumble to the point that it is about to stall? Because I hardly notice any engine stumble when I lift up on the valve. I wonder if there is carbon blockage and that might cause high NO in the exhaust manifold.

Thanks

[Harrythook]

The EGR provides exhaust gas to the intake side basically to help reduce combustion chamber temps and control detonation during combustion. If the system malfunctions you will get pre-ignition or “ping” that will be picked up by the knock sensor, sending the ignition system to a different mapping to compensate.

First step is to verify intake system is free of vacuum leaks and fuel delivery is OK. The next step is to look at EGR system, as you stated there could be blockage in the passages or a faulty valve. At idle if the valve is opened there should be a marked change in idle quality.

The testing and inspection procedures for these steps can be found in the FSM on this site.

[asoomal]

On my 1992 KA24DE, the engine would stumble and die when I would manually open the EGR valve.

I believe that if it doesn't, there may be carbon blockage in the EGR pipe and also in the EGR port in the intake runners.

There is an allen plug on the intake manifold, remove that and use a long bottle brush soaked in carb cleaner, solvent, etc. to clean the passages.

[kendem]

Thanks. About a year ago, I removed all the egr components, egr and bpt valves, egr tube, vacuum solonied, vacuum hoses, ect and tested/cleaned them.

However I did not remove the the egr block off plate (I think that's what it is called) and inspect further. I'm not sure where that allen plug is you are referring to? I am hoping to not have to remove the entire intake manifold to clean out the egr passage.

I do have the FSM so I will look again for that allen plug.

Thanks again.

[asoomal]

Right above the throttle body.

Ignore the hand.