Hi, I am not a mopar expert despite my username, I’m working on a friend’s 1977 B-series van with a 5.2. Can someone help me identify this component (see photo)? The last person to work on it seems to have plugged the alternators field wires into this component instead of the alternator. Now I just want to know what that component is so I can reference a wiring diagram, etc. many thanks, any thoughts or suggestions as to determining the mystery component are welcome.

 

A vacuum delay solinoid for that valve it’s connected too… EGR or AIR Divertor!!!!

 

Yup, that is temperature sensitive. The EGR won't open up until it warms up. It's best to plug them off entirely. The EGR was meant to run richer but by creating an opening to the exhaust it ran leaner. Technology wasn't so good back then.

 

Thank you both. I’m looking forward to going back and finishing up this detail on the van.

Do you know if the solenoid is open when not energized, allowing vacuum and opening the egr valve? My hypothesis is that the 12v that should have been going to the field windings of the alternator was the energizing the solenoid and closing the egr, making the engine run smoother at idle.

 

EGR only opens off idle. It's closed at idle. If it was open the car would stall. The solenoid got power when warmed up enabling the egr to open. If it was mine I WOULD NOT make it operational. It created hesitations and surging. In an effort to cover my butt. It's unlawful to tamper with the emission system.

 

Thanks for the responses. I got a workshop manual for b series vans so I figured I’d post some pics of the egr info.

 

Back in the day EGRs were the start of fuel/emission efficient vehicles. By allowing exhaust gas into the intake actually cooled the detonation.
They almost always caused a hesitation or surge when opened. Some mechanics would install a BB in the vacuum line preventing it from opening.
The system looked intact yet prevented the annoying EGR problems.

 

Just to cap off this thread, in the picture from the first post you can see a capped off vacuum line. That would have gone to the egr I think but all the egr equipment has been removed. The unidentified component is a vacuum solenoid controlled by a high idle switch. The remaining vacuum line goes to a valve that whose linkage raises the idle a few hundred rpm when you hit the switch.

 

Chrysler used solenoids as such to set the idle. The solenoid would shut down when you turn the key off reducing the chances of (run-on) or dieseling.

 

1- Line to the carb
1- Line to the Air Amplifier
1- Line to the Thermo Vacuum Switch