So this was discussed awhile ago in a thread but I can't find it and I'm not sure if it even really came to a conclusion but my truck wasn't acting up as bad at that time... anyway it's a 96 f150 inline 6 2wd manual and when i drive for more than 45 minutes or so it starts to missfire a bit. If I keep driving or shut off the engine and restart it, it'll get much worse and barely run or get up a hill. To give you a true idea of how bad it is I had the gas pedal to the floor in 4th gear and I was only going 40 mph between 2600 rpms to 3000. I don't know the actual rpms because the needle bobs all over the place when this happens... code scanners when it's not doing this show a slight missfire in #1 cyl, and something with the crankshaft position (I did replace the crankshaft position sensor with no affect). What it seems like could be happening to me is that somehow the timing is being thrown off but I'm not sure what would cause it to do that. It seems to have an after market temp gauge in it and temp sensor, does the computer use the stock temp sensor for fuel, air, timing? If so I could have the problem there being the stock setup does not function... any information to how these truck work with setting timing and air fuel ratios and what sensors there are to do what is greatly appreciated even if you don't know the cause of this problem! It's probably not something comon from the look of things! Thanks guys!

 

What is the code, by number, and when was it displayed?

What "crankshaft position sensor" did you replace?

A sure sign whatever you replaced is most likely not the correct part. I suspect the PIP sensor (aka stator) inside the distributor is bad.

 

I'll have to check the actual numbers, I took it to AutoZone to have it scanned, they gave me receipts with everything on them. The one I replaced is located above and to the left of the harmonic balancer if you're looking at it face on.

 

The sensor you describe is used only to sense mis-fires. It's not a crankshaft position sensor. That function is derived from the PIP sensor inside the distributor.

 

Gotta love the expertise of minimum wage highschool kids at autozone.... I'll check on the pip sensor, should I do that or replace the whole dizzy?

 

I suggest to do your own troubleshooting: Ford Ignition Module Test. Fender Mounted Module (ICM).

If you do find the PIP is bad you can tear down the distributor and replace it yourself, but it will require some special tools. If you do opt for a complete distributor swap be aware many so-called "rebuilt" distributors have bad PIPs in them. Very few rebuilders actually test the PIP sensor. I highly suggested a brand new one.

A description of the stator (PIP) replacement procedure.

STATOR ASSEMBLY REPLACEMENT

Fuel Injected Engines

V8 ENGINES

Remove the distributor assembly from the engine.

Remove the ignition rotor from the distributor shaft.

Mark the armature and distributor drive gear with a felt tip pen or equivalent, to note their orientation. While holding the distributor gear, remove the 2 armature retaining screws and remove the armature.

Do not hold the armature to loosen the screws.

Use a suitable punch to remove the roll pin from the distributor drive gear; discard the roll pin.

Position the distributor upside down in a suitable press. Using a press plate and suitable driver, press off the distributor drive gear.

Use a file and/or emery paper to remove any burrs or deposits from the distributor shaft, that would keep the shaft from sliding freely from the distributor housing. Remove the shaft assembly.

Remove the 2 stator assembly retaining screws.

Remove the octane rod and screw.

Remove the stator assembly.

Inspect the base bushing for wear or signs of excess heat concentration. If damage is evident, the entire distributor assembly must be replaced.

Inspect the base O-ring for cuts or damage and replace, as necessary.

Inspect the base for cracks and wear. Replace the entire distributor assembly if the base is damaged.

 

Alright so I'm wondering if it could be the coil going bad but I'm not sure what the pip sensor actually does so maybe it is still that, I hooked up a spark plug test light between the coil and distributor and when the engine is cool I get a slight pause in the pattern of the light rapidly flashing, every 18 seconds to be exact. As the engine warms up and becomes to run rougher and rougher I notice the pauses get more prevalent at one point happening every 5 seconds. To me that seems like the coil unless the pip sensor is what controls the coil then it seems like it could be both. What do you think?

 

Any codes what's so ever usually a bad pip will post a code. There are really only three things in the ignition system pip sensor, icm and coil. This is heat sensitive and any one of the three are capable of having heat issues. An ignition scope can read the Hall effect pattern from the pip. I am not a big fan of throwing parts at problems. But I keep a spare coil and icm on hand just to test with. You can probably pick up both at pick and pull for next to nothing. If you do this get the same color icm either gray or black. I know of no real difference in coils for this era.

 

I can say this I did try switching out the Icm with a brand new one and it didn't change things, I think I'll take your advice and try the coil being that a coil is cheaper than a pickup or full dizzy. I think new at advanced they are like 20$

 

Coil didn't change anything, has to be the pip then right?

 

Reference the link I posted earlier. It would have saved you a lot of guessing.

 

That's what I did, everything tested out ok. I think all those methods are for a no start condition...

 

Test the PIP signal when the truck is acting up.

 

I did it when the truck was acting up and it tested out as it being bad, I used a bolt meter as well and read between 5 and 6 volts. Not enough for my test light to respond apparently. I replaced the whole distributor with a brand new one and it didn't help any.. timing may be off a bit, it got late and I had to shut the operation down. But I had the timing good enough to where it fired up but was still missing a good bit. As I let the truck run it quickly got worse and sputtered out... so if anything it got worse with a new distributor which makes me think it actually had no effect and the timing is off. But the miss should have gone away if it was indeed the pip... could it be a bad wire or something dumb?

 

New as in NEW or rebuilt? Many rebuilt units have bad PIPs.

Either way retest to verify the PIP signal is dropping out or not. If it's solid now you could have a bad connection at the coil. Another common problem area.