You should have a permanent Vac system layout sticker under your hood. I think mines on the air filter box cover.

 

Ok so I found a few schematics on the o2 sensors. It seems there are 2 white wires that power the heating element and a black wire for voltage back to the computer. The extra wire is to ground for the o2 sensor. This seems to make sense that they are used interchangeably because the sensor is grounded through the exhaust pipe anyway. So dropped in the new unit. I haven't run the seafoam into the intake yet because I have a tank full of B12 and I don't want to mix chemicals. I did use some B12 throttle body cleaner spray in the intake. So now I have a clean, smooth, quiet, engine that idles wonderfully and pings on the highway under 3/4 throttle. So I cant say we aren't making progress, it runs better than ever. It just keeps pinging. Is there a good way to test the computer on the distributor?

 

Article No.
94-4-10
02/23/94
^ BUCK/JERK - 5.0L - SPARK PLUG WIRE ROUTING AND FIRING ORDER
^ IGNITION - 5.0L - SPARK PLUG WIRE ROUTING AND FIRING ORDER
^ MISS - 5.0L - SPARK PLUG WIRE ROUTING AND FIRING ORDER
^ SPARK KNOCK - 5.0L - SPARK PLUG WIRE ROUTING AND FIRING ORDER
^ SURGE - 5.0L - SPARK PLUG WIRE ROUTING AND FIRING ORDER
^ ENGINE - 5.0L - SPARK PLUG WIRE ROUTING AND FIRING ORDER
LIGHT TRUCK:
1987-93 BRONCO, E-150, E-250, F-150, F-250
ISSUE:
Engine miss, spark knock, buck/jerk, surge and other driveability concerns may be caused by induction crossfire. This occurs because of improperly routed spark plug wires.
ACTION:
If spark plug replacement is performed, the correct firing order and spark plug wire routing is essential to prevent the possibility of induction crossfire between cylinders. Refer to the following procedures for inspection of the spark plug wire routing and firing order. Properly reroute the spark plug wires if required.
FIRING ORDER
^ The firing order for 1987-1993 vehicles is 1-5-4-2-6-3-7-8. If # 7 and # 8, or # 2 and # 4 spark plug wires are routed next to each other at the separation bracket, an induction crossfire condition can occur.
^ To eliminate the possibility of the coil wire becoming disconnected, route the coil wire under the spark plug wires at the distributor cap.


Note: for 87-93' only/// 94+ F.O. changes to the HO routing

 

SPARK KNOCK - SERVICE BAY DIAGNOSTIC SYSTEM PROCEDURE - THICK FILM IGNITION SYSTEM (TFI) WITH 5.0L EFI ENGINES AND 5.8L EFI ENGINES
LIGHT TRUCK:
BRONCO, ECONOLINE, F-150-350 SERIES
ISSUE:
Spark knock may be caused by variability in ignition PIP (Profile Ignition Pick-up) output due to a combination of engine torsional vibrations and distributor electrical characteristics. A spark advance spike is generated which repeats every eight firings.
ACTION:
Perform Service Bay Diagnostic System procedure and, if necessary, replace the distributor.
(A spark advance spike occurs every 8th cylinder firing/ this requires distributor replacement if occurring, not just the PIP sensor)

 

do you have this diagram for routing '95 wires?


**edit** never mind I found it

 

Me too!

 

thanks ymeski56. You are truly a very helpful member of this forum.

 

Seriously!? Between the 2 of us we couldn't come up with that one a month ago? #2&#4 were crossed where they run under the intake. She purrs like a kitten now. Must be time for a road trip. Thanks for all the help. You kept me sane.

 

That's good to hear! Your welcome.

 

ok so i just got my first f150. its a 1990 xlt larriat. and today i was re-wireing the spark plugs because he wires were shot. when i disconnected the center plug on the distributor cap i broke one of the metal nipples off. it didn't break from the cap but from the other connecting point at the opposite end of the wire. now my problem ii dont know what that part is called so i cant find the piece to fix it. if anyone knows the name please let me know. i needto repar it and have it ready by monday for work. please please help!