Hey Truckin' Bob, I replaced the PCV line (dry and loose), put clamps on the PCV and the vaccum port side, pulled both the vacumm tree and the nipple for the PCV, wire wheeled them and put new thread tape on them. I also pulled the O2 sensor (only a few months old) and cleaned the sensor and the connection on both sides with carb cleaner.

The truck instantly had a smoother idle and WAAAAY more power... but... once it warms up it still has a little shake and misses a little bit, but less frequently. In addition to that the check engine light comes on after 5 miles of driving, but when I go to pull the code it says that the truck is in gear with the AC on. Code #522. The truck has always had that code and it never caused the light to come on.

What do you think?

For some reason no one offers either the base gasket, or a rebuild gasket set for the throttle body! sheesh.

Fuel mileage still sucks too.

So far your advice has been the best! Thanks Truckin' Bob!

 

Your dealer should have a throttle body gasket in stock.

 

I also pulled the O2 sensor (only a few months old) and cleaned the sensor and the connection on both sides with carb cleaner.

Your truck has been running pretty rich for a while hasn't it ??
Your current O2 sensor may be shot---I'd re-check it for proper specs before thinking it's working correctly.

In addition to that the check engine light comes on after 5 miles of driving, but when I go to pull the code it says that the truck is in gear with the AC on. Code #522.

Are you 100% sure it's 522 and not 552 ???
552 is an air management system failure (would throw a Check Engine light in about that time frame) and yes, 522 is "vehicle is not in park or neutral during KOEO".

If it is in fact a 522 code you don't have something telling the computer it's in park or neutral while reading the codes. That might be a BIG clue as to what's wrong !!!

Was the computer (PCM) ever changed by you ?
Do you know any history of the PCM in your truck ?

You might try taking your VIN # AND your PCM # to your nearest Ford dealership and have them get the emissions calibration # and have them cross check to make sure you have the correct computer (PCM) for your truck.

All computers (PCM's) are not all the same.
Some are set up for automatic trannies, some are calibrated for the peoples republic of California emissions (Dont' I know it !!), and various other configurations.

I went through all that bull**** as I thought I had a bad computer.

I'm thinking someone may have grabbed (from a boneyard) a different year, model, or emissions set up computer (PCM) and stuck it in your truck. Worth checking..........


For some reason no one offers either the base gasket, or a rebuild gasket set for the throttle body! sheesh.

Not true here in California. Most ALL of the parts stores sell 'em. I bought some gasket material and cut out my own. I'ts much thicker than anything I could buy, didn't take but a couple of minutes to cut out, and I KNOW FOR SURE it won't be leaking anytime soon.

Fuel mileage still sucks too.

You keeping your foot out of it ????
I get 17mpg and that's with a very light foot.


We'll get you through this. Just keep


Bob

P.s. My truck does the "shake" and kind of misses at idle too. I was told it's from the VERY lean idle program set up in the computer to satisfy emissions.
Whether or not that's true, I don't know.

 

oh its true...Ford leaned the 300 out just enough to keep it from burning up a piston...

 

I pulled off the throttlebody today and dissassembled it. It was EXTREMELY filthy and caked with oily dirt residue on the back side of the butterflies and in all the ports. That thing is totally clean now. I also pulled out that hex head plug on the top of the intake and gave it the treatment. I bought a new base gasket from Ford for 5 bucks and bolted everything back together...

It runs one helluva lot better and has good power all the way around with A/C on or off. It pulls pretty hard in all gears and the buffeting sound is ALMOST gone. You really have to shut the hood, turn off the stereo and stand next to the tail pipes to hear any form of poofing or whatever. The exhaust still smells extremely rich though. I was thinking, is there a cold start mode built into this truck? Maybe whatever controls that mixture setting is sticking and is kinda making it a choke stuck situation like with a carburetor.

The code that I pulled said that the truck was in gear with the A/C on. It's because (I think) i've got my neutral safety switch bypassed with a paperclip. Actually the owner before me did it and I really don't have a choice, because the part that the connector plugs into is gone. It is handy for starting the truck without sitting in it, especially if you're greasy like I am when I work on this thing.

I've never touched the computer or have known anyone that did. I've known the truck for almost two years now and it's always had poor fuel mileage.

I guess it's impossible to know really, but, is there a certain year/model/ certain optioned truck computer that would give my truck a better set of parameters, for either performance or fuel economy? I thought it would be worth asking, though it is kinda off the wall.

I'm going to screw with that O2 sensor again because that was the only sensor I messed with before the check engine light came on.

Thanks alot for the help. Without everyones knowledge and experience I wouldn't be as close to correcting this problem as I am!

 

I'm going to screw with that O2 sensor again because that was the only sensor I messed with before the check engine light came on.



Good for you cjsteak !!!

Yeah, I'd give that O2 sensor another lookin' at.
I've always been told to never clean or try to clean them.
You might be looking at buying another one though.

As far as the computer goes.....as I said in an earlier post, take your VIN # and the number off of your PCM and run it down to your Ford dealership and have them make sure the emissions calibration numbers match with your PCM.
It probably does and would make you feel better knowing your truck hasn't been hacked up !!!

The computer does however go into either an open or closed loop (too lazy to look it up right now) during warm up and the system runs rich ( all you pro mechanics out there correct me if I'm wrong here ) till the computer sees the truck is at a specific operating temprature. I've also read that this "warm up" cycle is time specific. I dunno' which it really is.

I don't think you have anything stuck...like a choke. Your EFI system is electronic and the various sensors constantly send input to the computer so that it can adjust (richen or lean) the system for maximum performance....... well......what Ford thinks it's trucks should run like.

Is there anything missing or disconnected from your air injection system ??
If so, that might be why your're sniffing a rich exhaust.
You know the air injection system pumps air into the catalitic converter to help clean up the exhaust emissions.
Had your cat checked ???
Just a hunch........

Let us know what happens after you fiddle with the O2 sensor


Bob

 

And.........sheesh, I forgot this...........

Once you've repaired all of that bad stuff under the hood, the computer will have to re-learn how to make your truck run at it's peak efficency.

It'll take a little while before that happens......some say 15 or so miles and others say several hundred miles. Don't expect to hop right in and have it instantly cured.


Bob

 

Hmmm.... I just thought of something that one of your previous posts made me think about Bob. If my neutral safety switch is bypassed, the computer thinks the clutch pedal is to the floor 100% of the time... When I put the clutch in at a redlight...does the computer go to an idle mode or something where it leans or richens or does something different to the parameter because it's (thinks it's) idling.

In other words I wonder if my truck even knows it's moving, if the switch is always depressed.

Feel free to tell me if i'm giving the computer waaaay too much credit here LOL... I really dont' think it would have an 'idle' mode but hey, worth asking! haha.

I'll try to run the computer and VIN numbers by the dealership today.

There aren't any sensors or anything electronic not plugged in or by-passed except for the neutral safety switch.

I don't have any cats (Walker Y Pipe) and the fresh air tube off the smog pump is just dangling. It goes after the O2 sensor so I didn't think it would be too important. I was planning on having the exhaust shop put it into the pipe again (makes a buzzing sound when you go down the road).

You're right about the computer re-learning stuff. It takes my truck a couple hundred miles to re-learn stuff... when a part goes bad on my truck it doesn't just stop performing well or anything like that, it's just a slow decline in performance, which I hate... because sometimes you don't notice it! lol... I wish my truck would just have a problem and run REALLY rough so I can tell when i've replaced the right part... this subtle stuff is for the birds!

 

could u breifly re-cap all that u did CJ? and bob, could u breifly list what all u said to check? i have a hard time reading long posts on the computer with my moniter (color is dark, hard to see). thanx

 

Here ya go OI...

*New PCV hose with hose clamps on either side. $2

New EGR Valve and EGR solenoid. $110 with Ford employee discount.

Cleaned O2 sensor connector. (possibly tripped check engine light) $0

*Replaced throttlebody base gasket. $5

*Completely dissassembled throttlebody and cleaned it spotless. $2

*Wire wheeled and put fresh thread tape on: hex plug (wasn't very tight) ontop of throttlebody, vaccum tree and vaccum port for the PCV. $0

New hose from dangling solenoid (between intake runners) to charcoal box behind headlight. $1

OI, the things you see with the * next to them are the things that made the most difference with my truck. I didn't see a difference with the other stuff.

Goodluck!

 

thanx ...

 

What he said.

Have any luck with the wiring diagram for your TPS yet ??


Bob

 

I hope the tune up stuff works for you. But if it doesn't you might try a compression test. The popping,huffing and puffing sounds could be bad exhaust valves or springs. Lets hope no serious problems, a compression test should rule that out.

 

Hmmm.... I just thought of something that one of your previous posts made me think about Bob. If my neutral safety switch is bypassed, the computer thinks the clutch pedal is to the floor 100% of the time... When I put the clutch in at a redlight...does the computer go to an idle mode or something where it leans or richens or does something different to the parameter because it's (thinks it's) idling.

In other words I wonder if my truck even knows it's moving, if the switch is always depressed.

Feel free to tell me if i'm giving the computer waaaay too much credit here LOL... I really dont' think it would have an 'idle' mode but hey, worth asking! haha.

Well, YOU may be on to something here.
I just pulled out my Haynes book and the neutral safety switch DOES go into the PCM @ pin 30. Pin #30 is listed as NDS/MLP.
Maybe one of the Ford Computer wizards can chime in on this and let us all know what that is or means ??


I don't have any cats (Walker Y Pipe) and the fresh air tube off the smog pump is just dangling. It goes after the O2 sensor so I didn't think it would be too important. I was planning on having the exhaust shop put it into the pipe again (makes a buzzing sound when you go down the road.

What I was thinking is that if the air injection system were hooked up it "might" dilute the exhaust and not smell so rich @ idle.

this subtle stuff is for the birds!

Agreed..........


Bob

 

thanx...helped a bit. i dont have my chiltons home so im clueless about specs...

anyway i ran some seafoam through the engine and it didnt do much. i did the EGR restrictor and it helped a bit but my slight miss is still there. pulled just the #1 plug and it was black and what looked like a slight carbon build up. it looked a little wet but not motor oil wet. gunna clean the plugs up and try to replace the o2...sorry to hi-jack ur thread CJ but seems like were almost fighting the same problem...