JC316

My truck is a 1995 F150, 4.9L, 5 speed. I have a nice little miss at idle, it can be felt through the stick shift and in the truck. Also, at 55-60MPH I get a major miss, the whole truck jerks as it looses power. It seems to only happen when the gas pedal is pressed at a certain angle, just enough to keep it cruising at that speed. Let off completely and it stops or go to 50% throttle or more and it completely stops. Seems to have plenty of power and it just passed the emissions sniffer for inspection.

Codes are:
522 - Neutral park switch. Likely due to a 5 speed.
212 - Spout connector grounded or disconnected. Likely because I set the timing.
327 - Electronic pressure transducer (EPT)/differential pressure feedback exhaust (DPFE) sensor/electronic vacuum regulator (EVR)

Unrelated to this problem, I have changed/done the following:

Ignition module
Pickup coil. Just the pickup, not the whole dizzy
Cap, rotor, wires.
Numerous vacuum lines replaced
Ignition timing set at 10* and up to 14* without change.

dirtcrew51m

Setting timing should have noting to do with spout code, is your spout connected? Its the gray thing that goes into a small plug in, and the idle and 60mph miss might be an injector.

JC316

Yes, the spout is connected fine. I will check the wiring in that area, see if something is shorting out. I thought about an injector as well, but it doesn't make sense that it only acts up at 55-60MPH.

aliens8mycow

If it's also missing at idle, let it idle at normal temp and unplug one spark plug wire at a time. If you have a miss, one cylinder won't affect the idle. From there, you just need to figure out if it's lack of spark, or lack of fuel.

JC316

Not necessarily, I need to find the source of the codes first. The DPFE was acting up on a friends 4.0L explorer and my 4.6L mustang and it caused a miss much like this. I definitely have something to look at with the spout connector since it's not supposed to fire when setting the timing.

Flatlander

Could be the catalytic converter if it does it after warmed up...

Motorman

JC316 Did you ever find out what was the problim. My 1993 dose the very same thing and I have been trying to fix it for 6 months, I tried Ford when I ran out of ideas but they were not any help, they were stumped to.