EGR valve question

[skidlid]

I am a new owner of a 1986 Buick GN. I have a question about the EGR system. My service engine light comes on. After a scan it shows the egr system is at fault. My egr does test fine with vacuum or movement. Should I have vacuum at this valve at idle, it seems to right now? It runs rough when the vacuum line is hooked up to it. Once the hose is disconnected it idles smooth. What should I check next?

 

[Raeban]

Since the EGR Valve opens with vacuum you should not have vacuum at the valve at idle. The EVRV will have vacuum and should seal off the line to the EGR Valve. The hose that is closest to the drivers valve cover should be the one going to the EGR Valve. Check to see that the hoses are not reversed and post back. Does your SES light come on at idle or when cruising?

 

[skidlid]

It comes on at idle

 

[Raeban]

Try this troubleshooting guide from the manual. It is the best for working through the issue quickly.

 

[Royal-T-Ltd]

Possibly a bad check valve or installed wrongly .....

 

[skidlid]

Where is the check valve for this located, I am new to these yet? Which way should it go?

 

[Royal-T-Ltd]

Where is the check valve for this located, I am new to these yet? Which way should it go?

 

[turbolou]

In regards to the EGR failures what i have found is transducers failures( that's the black box on top of the intake manifold ) the other is the neutral safety switch on the steering column bad or out of adjustment. If the switch doesn't work properly the car doesn't know what gear its in to operate the EGR valve . This has to be checked while in drive with rear wheels off the ground & in motion.

 

[skidlid]

Thanks for all the help, replaced the egr solenoid and all was cured!