Anyone have a step by step guide for removal of upper intake plenum on a Econoline with a 302 engine?

I hope the plenum can be removed without pulling the engine.

Looks hard with all the vacuum lines and gas rails in the way. Can the plenum be removed over the top of the fuel rails to the rear of the lower intake, thru doghouse.

Hopefully, the replacement of the lower and upper intake gaskets will solve the high idle problem.

I've replaced the IAC and TPS. The new TPS voltage is per spec. (0.85-4.5v, idle thru WOT).

Removed IAC and duct taped opening. Duct taped throttle body valve openings and still have high idle. 2000 rpms or higher, who knows for sure, sounds like the engine is going to blow, that high of idle.

No vacuum readings on the vacuum lines that meet at the top of the plenum (brake booster, fuel line, other lines that join at the top of the plenum).

Tested for codes with 3145 reader.

KOEO= no codes

Was going to check timing but could not find distributor spout disconnect.

KOER= 12, 13, and 25 codes
12=rpm at idle out of range/high
13=rpm at idle out of range/low
25=Knock not sensed during Dynamic Response Test

thanks for all suggestions.

91 E150 5.0 AT LWB 120K+ miles

 

That high of an idle.....I would check the Temp sensor the the computer first, sounds like it's stuck in a cold start loop? Throttle cable stuck.....