Jump to content

EGR Valve/Solenoid Wiring help


Trovan
 Share

Recommended Posts

So, my buddy bought a fixer-upper '94 Pathfinder with his Biden-bucks. Here's the problem:

 

It runs, but the engine seems to flood over a few minutes of running, especially at higher RPMs. It start to run rougher and rougher until it basically sputters out and dies. Then you have to wait a while before you can start it again. Likely due to wet spark plugs (I think).

 

I think the problem could be the EGR valve and solenoid. As neither is attached to the electrical system at all. Please see the attached photo. The EGR Solenoid is circled in red, and the connector coming from the EGR Valve is circled in blue. The thing is, there are no connectors anywhere near there for either to connect to. I'm honestly at a loss on how to fix this issue.

 

Can anyone provide some guidance?

Link to comment
Share on other sites

I doubt it's flooding with fuel, but the EGRC solenoid is open when not powered, so unless it's been blocked off somehow, that EGR valve is wide open. (I remember my '95 stalling out once, barely ran, wouldn't idle, turned out the EGRC plug had fallen out somehow. Started right up when I plugged it back in.) Maybe the fast idle/cold idle is providing enough air to keep it going when the engine is cold.

 

I had a look at mine and the wiring for the EGRC solenoid runs along the driver's side valve cover, under a couple of vac lines, and is attached by a clip/zip tie to a tab on the valve cover towards the back, right under the IACV (fast idle valve, the tall one with the plug on top). Mine doesn't have an EGR temp sensor connection on the valve itself (pretty sure that was California-only), but there's an empty connector not far from there that might be related.

 

If the wiring is jacked up, or you want to confirm that it's the EGR, pull the vac line off the EGR valve (and plug it with a golf tee or something, it should be sucking air if the engine's running and the the EGRC solenoid is open). If the EGR valve is working, that should close it. If it's not working, you could loosen the bolts holding it to the manifold and slip a piece of pop can or something in between as a temporary block-off.


Download the service manual from Nicoclub and check out the EF&EC section. Lots of diagnostic info in there. The EL section has a harness layout that should help you find where the EGR connections are supposed to be and which harness they're in so you can track them down. Hopefully some muppet didn't hack up the harness.


It's also possible that the EGR is already blocked off and something else is giving you issues as it warms up. Given that the EGR has obviously been messed with, though, I would start there.

  • Like 1
Link to comment
Share on other sites

1 hour ago, Slartibartfast said:

I doubt it's flooding with fuel, but the EGRC solenoid is open when not powered, so unless it's been blocked off somehow, that EGR valve is wide open. (I remember my '95 stalling out once, barely ran, wouldn't idle, turned out the EGRC plug had fallen out somehow. Started right up when I plugged it back in.) Maybe the fast idle/cold idle is providing enough air to keep it going when the engine is cold.

 

I had a look at mine and the wiring for the EGRC solenoid runs along the driver's side valve cover, under a couple of vac lines, and is attached by a clip/zip tie to a tab on the valve cover towards the back, right under the IACV (fast idle valve, the tall one with the plug on top). Mine doesn't have an EGR temp sensor connection on the valve itself (pretty sure that was California-only), but there's an empty connector not far from there that might be related.

 

If the wiring is jacked up, or you want to confirm that it's the EGR, pull the vac line off the EGR valve (and plug it with a golf tee or something, it should be sucking air if the engine's running and the the EGRC solenoid is open). If the EGR valve is working, that should close it. If it's not working, you could loosen the bolts holding it to the manifold and slip a piece of pop can or something in between as a temporary block-off.


Download the service manual from Nicoclub and check out the EF&EC section. Lots of diagnostic info in there. The EL section has a harness layout that should help you find where the EGR connections are supposed to be and which harness they're in so you can track them down. Hopefully some muppet didn't hack up the harness.


It's also possible that the EGR is already blocked off and something else is giving you issues as it warms up. Given that the EGR has obviously been messed with, though, I would start there.

 

Thanks for the response, Slartibartfast (absolutely love your name. I understood that reference.gif). I'll run those tests on the EGR and we will see what we can find out. There are also some other loose connectors toward the back of the engine bay, on the passenger side. Gotta figure out what is supposed to go there. Some one really mucked things up in there.

 

The service manual link you sent gave me a 404 error, but I will see if I can get my hands on one.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...