cwcorrea

Hi, guys.I did not pass smog and I was going to replace the EGR valve and picked up a used one from a wrecking yard that the owner says was good. It's a Jeep wrecking yard and they do repairs, so i'm assuming it's going to work. In any case I want Is to check my old EGR Valve and check the used one I purchased
I don't know the best way to check them. And there's not much information on a 1990 Jeep Cherokee EGR valve. I scraped the old gasket off and i've been Spraying it full of carburetor cleaner And the insides actually look pretty good with very little build up. I live in California so I need the EGR valve so no I cannot plug it off. I appreciate the help.

exasemech

There are others on here that know more about that year than I do , but I would start here:


https://cruiser54.com/?p=119

The bottom line is that there's a lot more to the egr system than the actual valve. Also there are other causes of high Nox: running lean, high engine temp, combustion chamber deposits, ignition timing, come to mind

Saudade

What were your smog numbers? Did the EGR fail the functional test?

cwcorrea

I have checked all lines, sprayed everything with brake cleaner AND starting fluid to check. I have replaced every sensor and accessory that can be replaced. New fuel tank, pump, regulator, injection, filter, spark, distributor. Cleaned throttle body. Etc. Untouched engine with 260k sat for 22 years. Bought new by my parents and was a commuter. Runs smooth, drives good.
Smog said I had wrong cat. New cat was CA legal but was one of two cats (supposed to be a pair). I just installed verified CARB approved Magnaflow. Smog said fuel cap was not sealed, Bought new cap. That was it from Smog. I thought maybe my EGR was not working right. Looked like one diaphragm post was bent. So I was going to pull and check.
I just don't know exactly what to do to check function and clean. I sprayed a lot of throttle body cleaner in the used one and seems clean. That is where I am at.
Thanks.