***, home many EGR threads can we pack into one forum?

Well let me add another. I have all the typical egr system problems signs. Rough idle, hates reverse, hates putting the engine under load at just off idle conditions, egr codes, etc.

What I've done:
Cleaned the EGR and passages the best I could.
Pressed up on the EGR, and yes, the engine idled even worse than it already did (not sure what that proved?)
Replaced the EGR Selonoid.

None of those have resulted in resolution of the problem: but 1 thing has. Disconnecting the ECM lead to the selonoid! ?

So what is your best guess? Is the ECM just constantly sending a signal to that selonoid to be open? Bad ground, or spliced wire?

If I took a multi-meter to that connector, what would I normally be looking for, and what is he computer's signal to open the egr? Does it ground out to open the EGR or supply 5v or 12v?

(Pulling hair out )

 

When I was troubleshooting my EGR I removed the vaccum line going to the EGR and hooked it up to my trusty Vaccum gauge. That way I could monitor the selonoid opening and closing.

Just for comparison, I showed no vac at idle with steady vac showing as i raised rpm's. If I held the motor at a steady RPM the selonoid would close showing no vaccum. But as soon as I gave it more throttle it shot back up again. If your's is open all the time it would show vac all the time.

Hope this helps.

 

Great idea with the vac gauge instead of using the multimeter.

But I don't understand what you said afterwards... My understanding is that you are taking these measurements between the selonoid and the valve, and were showing steady vac at idle? Wouldn't that mean the egr would have been partially open? Then when it should be showing vac (at a steady cruise RPM) it wasn't showing any (meaning the valve would have been closed) but upon sudden acceleration it would be open again?

Isn't that exactly the reverse of how it should work? Vac operating the valve diaphram to pull it up...

Did you determain that your selonoid was bad in that case or what was the end result of your testing?

 

what about disableing the EGR? can you only do it through chip burning?

 

That's the point - I don't want to disable the EGR, or I would just leaave it unplugged. I *NEED* the EGR to pass emissions tests, but it's REALLY iritating to drive as is now because it feels as if it's ALWAYS open.

***EDIT IN***

Saga gets better - took the multimeter to the selonoid - ecm is not closing the circuit. My only thought was that the vac lines where switch on the selonoid... so the new question is...

Which port on the selonoid is the vent and which is the egr vac?

 

Just throwing this out there...

If by any chance you have a very "open" exhaust system or a huge exhaust leak (or many small ones), you will lose so much backpressure that your engine will not hold enough vacuum for the EGR to function normally.

 

Sorry, I don't have any pix of that here at work, but I think I remember a post no too long ago where it was detailed very clearly....

 

Just to clarify that, like I said I had no vac at idle. But, as soon as I opened the throttle and as long as I continued to open the throttle I showed vac. When I held steady or let off vac wewent away
Basically I showed vac only during periods when I was actively opening the throttle. And no vac when at idle or a steady rpm. Hope that helps.

 

Exhuast leak - that I do have. Where should I hook a vac. gauge up too to check for that, and about how much should I be checking for?