I was changing the thermostat on the '89 3-door coupe today, when I was reconnecting the vacuum lines, I broke the plastic nipple on the valve/sensor/switch?? directly behind the thermostat housing.

 

It has the 1" long "L" shaped vacuum line going to the branch mounted to the thermostat housing and proceeds to the canister by the radiator. It has a wire going to it, and another vacuum line running towards the back to the trans with a line T-ing into the intake manifold and another T-ing into the ball vacuum reservoir on the passenger strut tower. It also has what looks like a knob or button on the side.

 

I have it temporarily patched for now, and she’s running normal. I’m just wondering what oddity's to blame on this thing till I pick one up from the yard???

I think you are talking about either the EVAP Purge Control Solenoid or the EGR Solenoid. On a turbo, there are two units right beside each other on the intake manifold that look almost identical.

 

Quite possible it wasn't working in the first place (I dunno haow many miles you have). IF it was working to begin with, you won't notice any definite difference now that it is broken.

 

You can test replacement units at the junkyard by measuring the electrical resistance between the two wire connectors. The plastic vac connectors like to break off.

 

Picture of a turbo engine taken from passenger strut tower area:

I broke that filter looking end when I was replaceing my turbo coolent hose. I left it off and the car still runs fine.

 

Looks like the one on the right.

Those solenoids do a couple different things depending on which one you are talking about. They are in place to control things that should only be on or off when the engine meets certain criteria. Usually this means the valve is opened once the engine reaches operating temp. The EGR is controlled in this way, as is the evap cannistor purge line. EGR is not on durring cold running as it would introduce a needless vacuum leak that could cause hessitation. The evap is evacuated of fuel vapor once the engine reaches temp in the same way - vacuum is applied to the purge line of the cannistor.

 

Follow the vacuum lines to determine what the valve controls - then determine if the part is neccesary or not. Incidentally, those valves can be repaired if they still work - just get the broken bit out of the hose, and JB weld it back on. A careful application of JB weld will make it stronger than original. Pretty common and easily pocketed in the junk yard too tho.

 

GD

Those solenoids do a couple different things depending on which one you are talking about. They are in place to control things that should only be on or off when the engine meets certain criteria. Usually this means the valve is opened once the engine reaches operating temp. The EGR is controlled in this way, as is the evap cannistor purge line. EGR is not on durring cold running as it would introduce a needless vacuum leak that could cause hessitation. The evap is evacuated of fuel vapor once the engine reaches temp in the same way - vacuum is applied to the purge line of the cannistor.

 

Follow the vacuum lines to determine what the valve controls - then determine if the part is neccesary or not. Incidentally, those valves can be repaired if they still work - just get the broken bit out of the hose, and JB weld it back on. A careful application of JB weld will make it stronger than original. Pretty common and easily pocketed in the junk yard too tho.

 

GD

It leads to the evap cannister. So, if it doesn't work, the cannister doesn't get purged and the vapors vent off??? Or are there other problems?

 

I fixed it by cutting off a short piece of tubing that fit inside both plastic pieces.

Yep - the vapor doesn't get evacuated..... I wouldn't worry too much about it. Those carbon cannistors are supposed to be replaced every 60k miles, so likely it's shot anyway.

 

If you like, just conect the two lines and it will evac the cannistor when it's cold. Doesn't matter much really it's just a passive emmissions thing. You could plug them both and never notice.

 

GD

Hocrest,

 

did you break off one of the nipples that the vacuum line goes to?

 

Or did you break the 'knob' looking filter like the right circle above? If you broke this, don't worry about it. It's just a vent to let the vacuum on whatever flapper move back to normal position.

I broke the nipple on the end leading to the cannister.