miketodstjo
NAXJA Forum User
- Location
- Saint Joseph, MO
This is my first post here, I've listened to alot of what you all have done for others, and it has always helped me out in my wrenching. I've got another problem with heater vents...
I have an 88 XJ Limited w/4.0 automatic.
Just replaced the water pump and hoses, thermostat and housing, steering pump and hoses, trans cooler and hoses, A/C condenser and reciever/drier + expansion valve, boiled the radiator, and rebuilt my alternator.
My right front fender has been 'bumped' in before I bought the Jeep, I can access just a little of the Vacuum Canister on the outside end, but cant remove it.
My problem is that like others, my vents will go to Defrost while under even a slight load, and they never fully disengage from the defrost(there is always a little comming out the defrost on all vent settings).
However, it seems that with the gear selector in 'Park', no matter how high I rev the engine(2500-3000 rpm) the vent will stay in the selected direction (vent, bi-level, MAX Air etc.) My cruise doesn't work but my 4x4 goes into Full or Part time mode with no problem.
I've looked at the lines and measured vacuum in a number of spots. My lines all look real good and my vacuum readings are as follows...
1- off the intake =35-38 cmh2o
reving the engine produces a momentary loss of vacuum followed
by an advance to 45-50 cmh2o vacuum.
2- at the canister, SOURCE hose is same as at intake35-38, or 45-50 with
revving.
black small tubing going to firewall and on to selector is 25cm-29
cmh2o, and looses a little vacuum on reving.
3- Halfway up the little black tube going to the firewall, I get 25-29 and it
will loose alot of vacuum (almost back to 0) before rebounding
and going up to 30-35, before leveling out around 25-29.
I've tried hooking up a NEW vacuum line from the canister to the firewall/selector, and the symptoms persisted. I tried eliminating the canister and hooking up a direct line to the firewall/selector (just to see what those symptoms were like) and got the same set of symptoms.
I've also tried looking at and resecuring the connections on the back of the climate control selector. But I didn't find anything wrong.
I'm stuck! I think it might be that the canister is bad; but I don't see any cracks in the canister, and it holds some vacuum. (as seen by the hiss an measurements I get when I release one of the hoses from it).
Is there something that might be gained by going in to the dash to trouble shoot? Are there any easy/quick ways to diagnos this further, or go into the dash?
Y'all have helped me so much before, with these threads and searches. Winter is comming fast and I need this vehicle to make it to the Hospital where I work at. Any help will be much appreciated...mike
I have an 88 XJ Limited w/4.0 automatic.
Just replaced the water pump and hoses, thermostat and housing, steering pump and hoses, trans cooler and hoses, A/C condenser and reciever/drier + expansion valve, boiled the radiator, and rebuilt my alternator.
My right front fender has been 'bumped' in before I bought the Jeep, I can access just a little of the Vacuum Canister on the outside end, but cant remove it.
My problem is that like others, my vents will go to Defrost while under even a slight load, and they never fully disengage from the defrost(there is always a little comming out the defrost on all vent settings).
However, it seems that with the gear selector in 'Park', no matter how high I rev the engine(2500-3000 rpm) the vent will stay in the selected direction (vent, bi-level, MAX Air etc.) My cruise doesn't work but my 4x4 goes into Full or Part time mode with no problem.
I've looked at the lines and measured vacuum in a number of spots. My lines all look real good and my vacuum readings are as follows...
1- off the intake =35-38 cmh2o
reving the engine produces a momentary loss of vacuum followed
by an advance to 45-50 cmh2o vacuum.
2- at the canister, SOURCE hose is same as at intake35-38, or 45-50 with
revving.
black small tubing going to firewall and on to selector is 25cm-29
cmh2o, and looses a little vacuum on reving.
3- Halfway up the little black tube going to the firewall, I get 25-29 and it
will loose alot of vacuum (almost back to 0) before rebounding
and going up to 30-35, before leveling out around 25-29.
I've tried hooking up a NEW vacuum line from the canister to the firewall/selector, and the symptoms persisted. I tried eliminating the canister and hooking up a direct line to the firewall/selector (just to see what those symptoms were like) and got the same set of symptoms.
I've also tried looking at and resecuring the connections on the back of the climate control selector. But I didn't find anything wrong.
I'm stuck! I think it might be that the canister is bad; but I don't see any cracks in the canister, and it holds some vacuum. (as seen by the hiss an measurements I get when I release one of the hoses from it).
Is there something that might be gained by going in to the dash to trouble shoot? Are there any easy/quick ways to diagnos this further, or go into the dash?
Y'all have helped me so much before, with these threads and searches. Winter is comming fast and I need this vehicle to make it to the Hospital where I work at. Any help will be much appreciated...mike