Unplugged connection

boggissimo · #1 (**permalink**) 08-19-2003, 04:52 PM

hi folks,

Can anyone tell me what the connection is on the passenger side, under the bonnet (hood), with a little cream-coloured unit? It's right near the front of the engine bay, and mine was disconnected. I haven't noticed anything not working....

It has green and black wires going into the connector, and blue and black ones coming out, and the two metal contacts are at right angles to each other in the connector. The cable from the unit goes somewhere into the darkness next to the cylinder head on the passenger side.

I plugged it back in and didn't notice anything happening that wasn't happening before! Any guesses?

Cheers,

Boggis

**Roadtrip** · #2 (**permalink**) 08-19-2003, 09:54 PM

If you're going to ask a wiring question, you've got to tell us what year and model car you're talking about.

boggissimo · #3 (**permalink**) 08-20-2003, 10:22 AM

Quote:

Originally posted by Roadtrip
If you're going to ask a wiring question, you've got to tell us what year and model car you're talking about.

**Bill** · #4 (**permalink**) 08-26-2003, 12:20 PM

Could be the fuel cut-off. Sounds like the same unit I have on my '78 Spider. It's a sensor that cuts off fuel supply and fuel pump during a rollover or hard collision. Post a picture if you can.

boggissimo · #5 (**permalink**) 09-30-2003, 03:22 PM

here's a pic of the unit I reconnected...sorry it took so long to get around to posting it!

boggissimo · #6 (**permalink**) 09-30-2003, 03:22 PM

another angle

boggissimo · #7 (**permalink**) 09-30-2003, 03:26 PM

Since I reconnected this unit, the car hasn't had any problems with intermittent loss of power/ignition that I was having beforehand - is it just coincidence?

**Roadtrip** · #8 (**permalink**) 09-30-2003, 03:43 PM

It's a distributor vacumn swtich to aid starting. Having it disconnected was probably preventing ignition advance. If that happens, you'll have a significant decrease in engine performance.

boggissimo · #9 (**permalink**) 09-30-2003, 04:27 PM

So are you saying the performance would be better with it plugged in or unplugged? I didn't notice any difference, in starting or performance generally.

**Roadtrip** · #10 (**permalink**) 09-30-2003, 04:46 PM

I'm away from home (and bored) and don't have the manual in front of me so I'm not sure exactly if it cuts off or cuts on vacumn when it's energized during engine start. Actually, it's just there to help initial starting.

**John M** · #11 (**permalink**) 09-30-2003, 05:11 PM

I have never seen that piece in action. I was under the impression its the vaccuum switch for the second set of points on a dual points distributor. My 78 had one......yes...had one. I am thinking that the 79 had a dual points distributor that kicked in the second set of points at around 3000 rpm. If its still working.....let it ride on plugged in. Its rare to see those still intact.

Best Regards,
John M

**papajam** · #12 (**permalink**) 09-30-2003, 06:30 PM

The '79 owners manual says it's a vacuum retard switch for the ignition timing and is used in conjunction with the dual point distributor. When there is no vacuum to the switch, ie at engine startup or under load, the ignition system uses the default, or retard set of points. When there is vacuum, the system switches to the second set of points which advances the timing about 5 degrees.
To test the system, check the timing with a warm engine and the vacuum retard switch hooked up. Timing at idle should be 5 deg. BTDC. Now disconnect or squeeze the vacuum hose to the vacuum retard switch. After a few seconds, the timing should change to 0 deg. (or TDC). If the timing doesn't change, the system doesn't work.
Wouldn't worry about fixing it though. I'd just set the ignition timing to 5 deg. BTDC and be done with it.

**Roadtrip** · #13 (**permalink**) 09-30-2003, 07:49 PM

Papajam -
Boy, did I get confused on this one. I assumed that the starter electrical circuit drove the vacumn switch with a distributor vacumn advance and not the other way around. The vacumn directs which points get used. Sheesh. Been working on my Jeeps too much recently!

**papajam** · #14 (**permalink**) 09-30-2003, 07:58 PM

Actually, the retard set of points can aid in engine starting. Ever try starting a hot engine with too much ignition advance? Has the symptom of a weak battery and it just ain't gonna start until either the engine cools down or the timings retarded.