Will carbon buildup cause my turbulence?

[monkeydude3]

Hello all~
I have a 1994 XL, 4.0L OHV 4X2 and manual transmission. It has 137k miles on it, and only 7k on the rebuilt transmission. New clutch line, clutch slave cylinder and complete clutch assy.

My problems are unusually high idle when warm (900rpm, sometimes more) and when I start it up after letting it sit having been fully warmed up, it will chug like it has a high end cam in it, and when I hit the gas a few times it goes away. Also when it's recently been started, I hear a sort of popping/spitting sound in the exhaust that goes away as I run it a bit.

I'm thinking I have a pretty decent carbon buildup on the inside of my engine, and am considering some seafoam. Would carbon buildup cause these things?

what's been done:

new plugs and wires
new fuel injectors (motorcraft)
new IAC
new DPFE
new EGR valve, solenoid and tube
new 02 sensors
New upper and lower intake gaskets (and valve cover gaskets)
new air intake temp sensor (one in the manifold)
new coolant temp sensor (for the ECU)
new radiator, with fresh coolant flush and fresh coolant
new fuel filter
new fuel pressure regulator


By all accounts this sucker should be running near perfect, but my luck prevails, and it does not! Oh well, any ideas, let me know


George
*Confused and aggrevated*

 

[Creager]

have you tried a different gas grade?

 

[monkeydude3]

no, I run regular, and at the price, it's all I can really afford. Will running mid grade or higher help my situatioN?

 

[Creager]

probably not, but it doesnt sound like your problem is really that abnormal anyway. 900 rpm isnt that high for idle, 750 is ideal... 900 aint that far off.

that popping/spitting i dont know what to tell you

 

[briwayjones]

It wouldn't hurt to try seafoam.

 

[monkeydude3]

The main concern is that as it gets warmer it idles faster... I don't get it. And it is NOT OVERHEATING either.. ::sigh:: I'm gettin rid of it soon anyhoo to get a 4 banger (gas prices killing me). It's near mint condition otherwise. Ice cold a/c, solid trans etc.... Anyone in the IL area who would be interested let me know

George