4.0L V6 with a rough idle.

[caplbi]

I'm new to this forum so I would like to say hello to everyone. I belong to a marine forum so I know these are very helpful.
I acquired for free a 1998 explorer xlt 66k miles and a 4lt v6 motor. The truck sat for over 2 years due to a no start problem and broken rear brake line.
After fixing the no start problem ( bad fuel pump ) and break line the truck ran very rough as I expected it would until I ran out the old gas.
As I added new gas and new filter and fuel system cleaner, the performance did not improve. So I started changing parts.
New plugs and wires. Not motorcraft. IAC valve, Throttle position sensor, crank position sensor, air filter, cleaned the MAF sensor, removed the throttle body and cleaned. I did notice that there was no gasket for the throttle body.
The truck is running better, still stumbles at idle and hesitates at 40mph, and struggles on hills with just the driver in it.
I read here that it might be a vacum leak and I think I hear one but cannot isolate the area. Any suggestions? Is there supposed to be a gasket between the throttle body and plastic intake?

 

[specialized7]

im having the same problem man, What Motor is it?

 

[BrooklynBay]

Welcome to this forum! I've moved your thread into the stock 95-01 section. Do you have any codes? Did you check the intake manifold gaskets?

 

[swetrid]

Just by adding new gas may not solve the fuel problem. It may only dilute the bad gas and still have running problem.

 

[ucluglee]

Is there supposed to be a gasket between the throttle body and plastic intake?

My '00 4.0 SOHC has a spacer plate between the throttle body and intake, and there's an O-ring gasket that goes between that spacer and the intake itself.

 

[caplbi]

p1506 code came up