93 GXE -- Lumpy idle, fautly fuel gauge.
 

My bro's 93 gxe has those probs above. But I was unable to duplicate any of them, however I was checking around the engine for any loose hoses and such and noticed these two things below:

1) First pic shows a check valve which is inserted into a hose that leads to the back of the intake manifold(?) (see second pic). The open end of the line is 'realeasing' vacuum -- if thats the correct term. (I can feel suction on my finger covering hole). I reversed the check valve and the suction stopped. My question here what is the check valve for? And which direction should the check valve be inserted?

pic 1
pic 2

2) 3rd pic shows a small crack (its actually a big rip) in another vacuum line leading to what looks lke the top port of the big canister (4th pic) under the fuse box in front of the battery. I will just get another hose and replace this line. My question here is whats the purpose of that canister and that vacuum line?

pic 3
pic 4


Im Just trying to diagnose his lumpy idle (he says once the car is warmed up, idle jumps from ~1k to ~500) and stumbles when parking, low speed turns etc... like it wants to shut off. I was unable to duplicate the funny idle or witness the fuel gauge randomly jump from E to whatever level is actually in the tank. (I'll also do a search on the gauge issue)

Thanks.

pic 1&2 heater coolent control valve on firewall. allow vacume at valve on firewall with one way. Valve should open/close, heat/AC

pic 2&3, vapor absorbtion canistor for fuel tank, repair bad vacume line.

Thanx for the reply. Just clarify the first response for me, should I position the check valve so I only see vacuum on the open end of that short hose ONLY when the heater/ac is ON? When heat/ac is off I should not see vacuum on that end?

Also, you said control valve 'on the firewall'. I found that open end just as you see in the pics, and I didnt see any open port nearby (or on the firewall) to connect it to. Is it supposed to vent to the atmosphere?

Thanx again.

Vacume all the time.
PIC 1, see the round silver can right in the middle of the two red circles? Thats the air operated valve that opens/closes the heater water flow. Just next to that is the electrical solenoid valve that controls the vacume to the water valve. The end of that tube in question goes to one of the two vacume ports on the electrical solenoid valve, and should supply vacume to it all the time.

Got it now, thanks again. :cool: