20GrandHipHop

Hello to all of my Ford Gurus! I can really use your help. Here is what I am going through:

I'm a painter and picked up a 1997 E-150 work van that has a 4.2 liter V-6. After it runs and warms up a little, the worse it runs. I'm getting the following codes:

P0301 (Cylinder 1 Misfire)
P0304 (Cylinder 4 Misfire)
P0102 (Mass Airflow Low Input)

Here is what I have done so far (get ready):

Replaced all spark plugs with Bosch Platinum Plugs
Replaced all wires
Cleaned MAF sensor with MAF sensor cleaner (MAF looks very clean and new)
Replaced coil pack with used coil pack (after installation, I still got the same codes).
Went BACK to the junkyard and got a different coil pack- same codes...
Took out ALL of the spark plugs and regapped to .54- still same codes
Swapped plugs 1 and 3- STILL SAME CODES
Went to junk yard and got a MAF- still same codes
Put a compression test on cylinder 1, while cold, and got 150 lbs

After all of this, it still runs like dog poop and is showing the same codes. I read in a Haynes manual that a bad crankshaft sensor can cause a cylinder misfire.

Has anyone experienced this at all? I'm truly stuck on this one. Any advice or diagnosis would be much appreciated!

Carcrazygts2

First get rid of the Bosch Plugs. Ford dont like them. I had a issue with my aunt 3.8 mustang where someone installed Bosch plugs. Had 2 misfire codes. Replaced them with NGKs and the codes went away.

20GrandHipHop

I replaced cylinder 4 with a motorcraft and still the same deal...I read that ford is touchy with plugs other than stock, but called the dealer a couple days ago and they said there shouldn't be an issue with those plugs. I guess I can give it a shot tho....even tho I don't think that's the issue.

03f15012

Motorcraft it seems. Just like Carcrazy said, I've heard these motors are very picky when it comes to spark plugs. I've got Motorcraft platinums in mine, and it runs great.

20GrandHipHop

So Motorcraft or NGK?? This is my first Ford so I'm still learning the details on these beasts..

03f15012

Yeah. Motorcraft is almost like Ford's "brand" of parts.

20GrandHipHop

That's what I thought. That's why I tried a motorcraft in cylinder 4 to see if it would clear a code, but the same thing. Are you saying I would have to replace ALL of the plugs to see IF the code clears??

kaboom10

Try switching coil on plug units and injectors also. they can cause misfires along with plugs.

20GrandHipHop

OH I forgot......After the it runs to operating temperature, the oil pressure drops ALL the way to low but only in gear. In park and neutral, the needle is in the middle...

03f15012

The oil pressure gauge is a dummy gauge. Its more of a switch than anything.