I have a '95 F150 with a 5.8L, E4OD and dual tanks.

The symtoms I have are:
1. Semi-rough idle
2. Low power.
3. Engine 'misses' or hiccoughs occasionally under load (hills, acellerating) in 3rd and 4th
4. Tach 'bounces' throughout entire curve
5. Cruise no longer works, but does turn on

Tested items:

Fuel:
Pressure reads 35psi key on-engine off. 30psi engine running. 40psi engine running with vaccume disconnected from the regulator.
New fuel filter
Same symptoms/readings with either tank selected
Vaccume is 21 in Hg during idle and drops normally with throttle

Ignition:
New plugs
New T.F.I. module
Cap/Rotor and wires 8 months old. Distributor 4 years old
At idle, timing is 10 BTC with spout removed, ~17 BTC with spout installed
Coil resistance is 0.5 ohms on the primary, 8.6 ohms on the secondary. I verified this with a new coil at Kragen, the new coil read the same.

Computer:
Tests OK
No codes
No 'Check engine' light during operation

I'm at my wits end on this. Any ideas would be appreciated.

 

USUALLY,a bouncing tach means a primary ignition fault...like a coil...wett cap,etc