Dies on idle after warming up

[madridalejandro]

I’m currently having a problem with idling on my tj. It starts up just fine on cold starts but once it reaches 210 degrees on the dash it starts to struggle staying on until it eventually dies. I’ve cleaning the iac and throttle body. What would cause it to die only after it’s reached temp.

 

[John Cooper]

I’m currently having a problem with idling on my tj. It starts up just fine on cold starts but once it reaches 210 degrees on the dash it starts to struggle staying on until it eventually dies. I’ve cleaning the iac and throttle body. What would cause it to die only after it’s reached temp.

View attachment 650162

How many miles? Have you taken a temp gun and checked the Cat temps?

 

[madridalejandro]

How many miles? Have you taken a temp gun and checked the Cat temps?

135k and no I haven’t tried that

 

[JKP]

Sounds like it's dying after it hits operating temp and starts running closed loop.

Any codes?

 

[madridalejandro]

Sounds like it's dying after it hits operating temp and starts running closed loop.

Any codes?

No codes

 

[Tjjerry]

135k and no I haven’t tried that

If the IAC is known to be working as well as clean, then you might check the Coolant Temp sensor which is used to “rich” and then “lean” the fuel mixture between cold and operational temp. It also helps the ECU adjust timing a bit when reaching temp and will cause the engine to go into EGR. All those can affect idle.

 

[macleanflood]

Check and see if your intake bolts are loose.

-Mac

 

[MikeE024]

I bought a rig that would die right around when the engine was fully warmed up. IIRC, the crank sensor wiring was being burned by the exhaust manifold. All that to say I’d be checking my wiring while you try to figure this out.

 

[ItchyDong]

Try unplugging your upstream O2’s and see what happens.