I got a 97 xj with the 4.0 in it. When I bought it, it wouldn't run without having to keep your foot on the gas. I replaced the broken header, thinking that's what caused it. I was able to get it to run but with a high idle because I left the vacuum line off the side of the manifold. I figured out the line runs to the valve above the carbon canister. If I remove the lime from the valve, it idles very low (about 400-600). I've blown throughout the lines and the lines don't seem clogged up. Have any of y'all had this problem and what did you do to fix it? Thanks!:badpc:
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Help with major vacuum leak
- Thread starter Dixie97XJ
- Start date
O-Gauge Steamer
NAXJA Forum User
- Location
- Colorado Springs, Colorado
With an open vacuum port the engine must idle very high as the Idle Air Controller, IAC, is being bypassed. The computer will add fuel to match the air being drawn in bypassing the IAC.
What I am not sure is what, exactly, is the problem. It runs fast with an open port, yup, it should. And, it idles where it should when the system is sealed back up. Again, just as it should.
So, what is the problem here?
What I am not sure is what, exactly, is the problem. It runs fast with an open port, yup, it should. And, it idles where it should when the system is sealed back up. Again, just as it should.
So, what is the problem here?
old_man
NAXJA Forum User
- Location
- Loveland, Colorado
If it won't run with the hose connected, then there must not be enough air going through the IAC port. Pull the IAC and clean the inside of the port with a small brush and qtips and scrub the pintle with a toothbrush and carb cleaner. Make sure the battery is disconnected while you are pulling the IAC and do not push or pull the pintle or you will break it.
souske
NAXJA Forum User
- Location
- The land of competition
On/in the throtle body
O-Gauge Steamer
NAXJA Forum User
- Location
- Colorado Springs, Colorado
This is a different symptom than what your first post reported. An idle of around 700 rpm is normal. Given that we now know it will not idle at all, then I completely agree with old_man that the IAC portion of the Throttle Body (TB) is at fault.
Either the ports are plugged with accumulated carbon or, the stepper motor has died. The second cause is a somewhat rare happening but it is a possibility. The IAC is located on the valve cover side of the TB at the back side of the TB. It is secured with two Torx fasteners.
My suggestion would be to remove the TB from the manifold to make it both easier and safer to clean out the ports. No sense in dropping stuff down the manifold...
All of the electrical cables are individually keyed to their respective devices. No worry about plugging the wrong one in when you reassemble the TB to the Heep...