Snorkel drawing in stovepipe air always

[RustyButTrusty]

I've recently noticed that the vacuum motor on the snorkel was not opening and closing the valve that directs air from outside or from the stovepipe. It was constantly open (allowing outside air). I found that there was a plug in the vacuum line, fixed that, and now I have the opposite problem being constantly closed (only drawing in hot air). I've done some looking around and found that the little gizmo inside the air cleaner is supposed to sense the temperature and apply vacuum to the vacuum motor accordingly?? So I'm guessing somethings wrong with this sensor, but I'm not sure how to check for sure. I read on another post here that there is an adjustment screw on it, but I don't see on on mine. Any thoughts on what I should check?

[frozenrotors]

I've recently noticed that the vacuum motor on the snorkel was not opening and closing the valve that directs air from outside or from the stovepipe. It was constantly open (allowing outside air). I found that there was a plug in the vacuum line, fixed that, and now I have the opposite problem being constantly closed (only drawing in hot air). I've done some looking around and found that the little gizmo inside the air cleaner is supposed to sense the temperature and apply vacuum to the vacuum motor accordingly?? So I'm guessing somethings wrong with this sensor, but I'm not sure how to check for sure. I read on another post here that there is an adjustment screw on it, but I don't see on on mine. Any thoughts on what I should check?

That little gizmo your referring to. Is inside the air cleaner, it's pre set at the factory. I wouldn't mess with the screw (that has loctite on it!)It's adjusted to sense the temperature in the air cleaner, and to open the vacum module mounted on the intake snorkel. Before I'd mess with that screw, I'd replace all the vacum lines, I think there's 3 total. One coming off the vacum module to the bottom of the air cleaner, and 2 more. One coming up from the lines behind the air cleaner (near the EGR valve)and another from the TBI...I think! The trick is figuring out the proper routing of the last 2. It would also be worth noting, that you should make sure there are NO kinks or places where these lines are 'pinched'. Mine had the line pinched where it mounts to the single nipple...on the other side of the air cleaner. It wouldn't fast idle correctly as a result. The 2 other nipples are side by side. One of which I believe is kind of an 'intake side' and the other I think is regulated by vacum and temperature. Kind of like a 'switched' vacum line!

[MY1PATH]

after changing vacuum lines check out my TBI info page in the pinned section. the little thermo sensor under the dome shaped cap loses its setting as the metal fatigues. Ajustments in 1/8 turn increments make a big differance. You need to close the hood to let it heat properly. the proper setting is for it to completly close the valve to the stove pipe when the intake is almost hot to the touch.

Messing with it won't ruin your engine it just changes how your engine warms up and restricts how freely your engine breathes when its open. I often leave that vaccum line plugged in the summer and when crossing water since warm up is not an issue and I don't want it to suck up water.

 

 

[RustyButTrusty]

I thought I'd start with the simple stuff first, and I was wondering if the two vacuum lines that connect to the sensor have to be connected in a certain order. I unplugged them the other day, and I when I plugged them back up, I may have attached them backwards? Would this cause an issue, or does it matter which port the hoses are hooked to?

[MY1PATH]

yes, only one of the hoses is shut off the the heat sensitive spring. the other hose connects the device to the lower mainifold. pop the cap off and see witch one is witch

Edited November 21, 2010 by MY1PATH

[RustyButTrusty]

yes, only one of the hoses is shut off the the heat sensitive spring. the other hose connects the device to the lower mainifold. pop the cap off and see witch one is witch

 

Thanks! I'll be sure to check that!

[RustyButTrusty]

Well I did some more checking today and I am still having the same issue. When the temp gauge is about in the middle, the door in the snorkel is still closed. I've checked, and all the hoses appear to be routed correctly and free of plugs, so I'm thinking something is amiss with this little sensor/switch. I mean I know i've got the vacuum, it just ain't shutting off. Too much vacuum! Any way I can test this thing? I used a hair dryer, but that test didn't seem to help too much.

[MY1PATH]

pop it open and tweak it. or get another one from the JY.

or just cap off the line and live without it.

Edited November 22, 2010 by MY1PATH

[frozenrotors]

Try taking a hand held vacuum pump and hooking it up to the line coming off the vacuum motor on the snorkel. If the flapper door in the snorkel closes under vacuum, then it's working properly. If not,it's probably defective or corroded on the hinges. There's probably a diaphragm in the motor thats leaking.