94 4.0L Misses when cold

[4x4Ranger]

Not sure what the deal is, but the engine idles fine and as soon as there is a load on the engine it misses. Once the engine is fully warm it is fine.

Anyone experience this before with a 4.0L? Truck has 180,000 with routine maintenance always completed.

 

[snoman6115]

ya my 98 will do that once in a while. not always wen its cold more when i put a load on it such as goin up a hill it will miss a couple times till it downshifts

 

[8sechonda]

ya my 98 will do that once in a while. not always wen its cold more when i put a load on it such as goin up a hill it will miss a couple times till it downshifts

mine does the same thing .. its like the tranny dont wann down shift or smthn then it stumbles.. dunno what it is..

for the problem on the thread cold idle air control possibly...

 

[hondaxr650]

Is it using any coolant? Classic symptom of a leaking head gasket or cracked head. Look at the exhaust manifolds where they bolt to the head. They'll usually have some white staining on the manifold on the bad cylinder if you have a leak.

 

[4x4Ranger]

I'll check out the exhaust manifolds for sure. I just fixed leaking coolant hose, so I'll be watching the coolant levels to see if I'm losing any.

Another odd thing about it, is it does not do it every day. Yesterday morning it missed until it warmed up. Today it didn't miss a beat.

Mine is a manual trans btw.

 

[tobyduck]

Check your IAC (or whatever you call it lol) valve, its on the throttle body and looks like a solenoid. It should have a connector with two wires and two bolts (10mm?) I was told to check this out and it was dirty on the inside when I took it off. It is like a choke on a lawn mower since you use it when it's cold but it's automatic since it's controlled by the pcm. The pcm can also sometimes be receiving false information from the temp. sensor and that can help fix the issue.