will die on low idle.

Hello everyone. I have an 85 XJ 4X4, 4cyl, 4 speed. With the 2.46 liter I4-1V Carburetor engine.

The carburetor has been upgraded to a weber, So if this should be in modified i am sorry.

So i have been doing quite a bit of work on the jeep in the past few months. I have had no issues until my way home this evening. So ill start with what i have done this weekend.
I had spotted a small puddle of power steering fluid under the jeep, Since i had somewhere to be i wrapped the hose that was leaking with a type of rubberized electrical tape. Yes 'i know thats ghetto but just a fix till i can get to parts store.
Then I changed the thermostat, and upper radiator hose. I have had an issue with the overflow bottle. It likes to empty out through a little pinhole on the edge of the upper hose. Like on the outside of the hose clamp.. But it never drains the radiator, just the overflow bottle.

So I drove it 30 miles. It was running very well I didn't even have any power steering fluid under it when i left where I was.

To finally get to the point. About a mile from home I stopped at a stoplight. The jeep died. Would not stay running unless i had my foot on the gas. If I let it idle it dies. If i just slow down too much, it dies.

Could this be related to the thermostat in any way? Can I adjust my carb to idle high, or would this be very bad?
I limped it home. The top radiator hose is hot, and the lower hose is warm If that helps..

Any suggestions will be very helpful

Thank you
Spike

Usually when this would happen "out of the blue" with a carb vehicle I would suspect a bad belt driven accessory putting too much drag on the engine.

Thanks Joe. Ill start checking things out after work today. I pulled the thermostat out last night to make sure I had it in right. Guess Ill be pulling belts now

"Usually when this would happen "out of the blue" with a carb vehicle I would suspect a bad belt driven accessory putting too much drag on the engine."

Hey Joe I have been looking around at several threads and I have been having the same problem just recently. When I start it and it is cold it idles too low to stay alive. I have to admit I am a rookie when it comes to jeeps but I have had this same problem in a previous car.

When the previous car was fixed the mechanic I took it to simply messed with the throttle in the engine so it idled high enough to stay alive.

How do you suggest I approach this on my jeep? Because I'm not quite sure what I would be looking for if I started to pull belts... Uneven ware or what?

By the way, I'm not sure if this is related but my jeep has also been having high reading as far as oil pressure. However, I just got a new pressure gauge and I will see if that clears that up tomorrow.. Thanks for any assistance

mamamul:

You didn't post your year/engine/etc., but here is a stab at it:

Do you have a/c? When you start it in the morning is the HVAC set to "defrost"? If so, the a/c compressor clutch will engage and that puts extra drag on the cold engine.

Try this--before turning off the engine turn off all accessories. Fan, radio, etc., and set the HVAC control off of defrost. Give that a try and post back if the symptoms improve.

Edit: turning off everything before you shut off the engine prevents a surge load on the ignition switch the next time you start. As the XJ ignition switch is prone to fail from overheating, this would be a good "preventative maintenance" skill to practice.

If you have a fuel injected motor then the idle is controlled by the IAC--Idle Air Controller. Some call it a sensor, but it is really a stepper motor that extends and retracts in the throttle body on command from the ECU/PCM--Engine Control Unit or Powertrain Control Module. The IAC is capable of handling all the idle settings on the fuel injected XJs, so cranking up the "screw" isn't necessary, in fact it tends to make things worse.

Checking the oil pressure with a manual gauge anytime you are concerned about the pressure readings is the right thing to do. The last time my pressure sender failed it pegged the gauge.

Belt driven accessories--alternator, a/c compressor, power steering pump, water pump, mechanical fan pulley, idler pulley, harmonic balancer (not really an accessory)--can start failing and put excessive drag on an engine a long time before there is any noise or component failure. You can observe the accessories for wobble, you can listen (with a tube in one ear and carefully move the other end around the engine accessories) listening for obvious sounds of something not rolling smoothly like bearings. Very carefully, moving belts are dangerous. No loose clothing, dangling jewelry, etc. If you pull the belt(s) you can turn the accessories by hand. Note that all will exhibit some amount of resistance to turning, it is a judgment call.

Well I had no luck with the belts. Since I am learning as I go along, I went to Baxter. I got a nice lesson on carburetors. I basically had to turn the idle screw way up like 2k rpm. Then work it down from there. While i was taking it down a little at a time i was adjusting the mixture screw as well.
The Baxter guy thought I might have a vaccume leak as well, but i couldn't tell any change in sound while using the propane. So Im thinking it was just running way too rich.

spikeypuck said:

Well I had no luck with the belts. Since I am learning as I go along, I went to Baxter. I got a nice lesson on carburetors. I basically had to turn the idle screw way up like 2k rpm. Then work it down from there. While i was taking it down a little at a time i was adjusting the mixture screw as well.
The Baxter guy thought I might have a vaccume leak as well, but i couldn't tell any change in sound while using the propane. So Im thinking it was just running way too rich.

Click to expand...

Rich would lower the idle, a vacuum leak would lean the mixture and your idle would run high.

From the situation/symptoms in your first post I wouldn't have thought of running too rich, but I didn't ask at what RPMs your idle was prior to the symptoms.

What idle were you at, and what is the specified idle on the sticker?