running lean and misfire

[snomaker321]

About a month ago i changed my plugs and wires with motorcraft plugs and autolite wires. Seemed to fix my misfire at first, but its back. In the past few weeks I have had times where it starts running like crap and the cel flashes, but not as often as before I changed the plugs. Just got back from advance auto to pull the codes. It came up with P0302- cylinder 2 misfire and P0171- lean bank 1.

Any ideas where to start are appreciated. I think I need to check for vacuum leaks and check the fuel system, but Im not sure about how to go about doing this.

The guy at the store suggested running some injector cleaner with a tank of 93 octane, said it would burn anything out of there but im skeptical.

I should also mention that I averaged 11.5 mpg on my last tank, which I just filled up yesterday. Any help greatly appreciated!

 

[triumphrider-1]

Lean bank 1 could be a bad O2 sensor on that side.

The Shell 93 octane fuel contains cleaning agents that help to reduce carbon build up in the ignition chamber (assuming everything else is working proplerly), so it couldn't hurt to run a couple tanks and see if it helps.

When was the fuel filter last changed?

 

[snomaker321]

Is there a way to test the O2 sensor, or just replace it and see what happens?

Is it actually the 93 octane that helps, or the cleaning agents? He said to run 93 octane with a cleaner(would probably use techron) to quote "burn out anything that might be in there (meaning the injectors)". Would the 93 do anything or would i get the same effect running a tank or 2 of regular with techron(or something else?) added?"

My dad tells me he changed it when I first got the truck in August '08, a little over a year ago, but I dont remember him doing it.(granted this is my first car and knew barely anything at the time about them)

 

[triumphrider-1]

I can't help you with the O2 sensor; there may be a way to test it but, I don't know it.

The fuel itself won't clean much, if your fuels have 10% ethanol that will help but might not be enough. I've never tested the effects of cleaning from differnt fuels, but I would assume the cleaning agents do a bit more than the fuel itself.

To me doing either would yield the same cleaning benefits. I was only suggesting the 93 to change to a different fuel, see if the fuel is partially causing it.

That should be fine then. The maintenance interval is about every 30,000 miles.

 

[snomaker321]

Anyone else have any suggestions for things to check/how to check them? Im still learning here but want to get this running right asap. thanks

just sprayed around with carb cleaner and could not find a vacuum leak. Pulled the wire off the plug on cylinder 2 and it was firing like crazy. So im thinking the problem is most likely fuel related. Can someone direct me to where I can find info on how to check fuel pressure etc? I havent really been able to find anything.

I questioned my dad more about changing the fuel filter, and he no longer thinks he changed it. So most likely the filter in it has nearly 130,000 miles on it since not much other maintence besides oil seems to have been done on the truck ever.

 

[creepinjeepster]

Checked your FPR yet? Filter would be another I'd check.

FPR (Fuel Pressure Regulator) can be checked by simply disconnecting the vacuum line from it. If fuel comes out from vacuum connection point while vehicle running, replace FPR.

 

[snomaker321]

checked FPR. no fuel leaked out. what else can i try?
checked again for vacuum leaks, still couldnt find any.

how and where do i check fuel pressure? i will need to get a gauge for that right? thanks for the help

 

[triumphrider-1]

Yep, you will need to get a fuel pressure gauge to check it.

Haynes has a write up for it:

The pressures for your year should be:
35-45psi with key on, engine off
25-35psi with vacuum hose connected at idle and
35-45psi with vacuum hose disconnected at idle also.

 

[snomaker321]

well i got a new fuel filter will get it on as soon as i get a chance, probably tomorrow after work or thursday.

ill have to look into getting a fuel pressure gauge. I might just be able to borrow one from my neighbor though, he's a mechanic.

In the mean time feel free to chime in with any more suggestions

 

[snomaker321]

changed the filter, didnt seem to help. well it did at first(first ride after) but now it seems to be back to its old habits. misfire and loss of power.

 

[Tader82]

There r two things that need to be checked. First one is the cam shaft potions sensor, there cheap so i would just by one and replace it. Second is the Ignition Coil, now there really is no way to test this with out a diag. scan tool. Here is the part number for the coil from ford F57Z12029A, about $158. but there is and cheaper and better coil.
ACCEL has two coils for your truck, there in the 80 buck range, but u need to note witch way the connector is pointed, one points to the passagner fender and the other is points up at the hood. here are the part numbers from summit, ACCEL 140036 (Vertical Harness), ACCEL 140035 (Horizontal Harness) this r the two thing u have not said u have checked.

Happy hunting

 

[cbxer55]

I thought the 96 had a distributor, therefore it does not have a camshaft position sensor. On 98 up the CPS is mounted where the distributor is on 97 down models. The distributor provides the same timing information the CPS does.

 

[Tader82]

nope it is coil

i have worked on them be for

 

[Ranger44]

There r two things that need to be checked. First one is the cam shaft potions sensor, there cheap so i would just by one and replace it. Second is the Ignition Coil, now there really is no way to test this with out a diag. scan tool. Here is the part number for the coil from ford F57Z12029A, about $158. but there is and cheaper and better coil.
ACCEL has two coils for your truck, there in the 80 buck range, but u need to note witch way the connector is pointed, one points to the passagner fender and the other is points up at the hood. here are the part numbers from summit, ACCEL 140036 (Vertical Harness), ACCEL 140035 (Horizontal Harness) this r the two thing u have not said u have checked.

Happy hunting

These coil packs are pretty robust and don't wear out nearly as often as people fear. There should be a resistance check, I'm not sure on the exact spec.

But, this isn't beneficial to shout answers out and hope it fixes the problem......yeah....the cheap stuff is fine and probably needs replaced anyhow, but when you get to EDIS6 coils, CPS's, etc. That's some money.

I thought the 96 had a distributor, therefore it does not have a camshaft position sensor. On 98 up the CPS is mounted where the distributor is on 97 down models. The distributor provides the same timing information the CPS does.

The CAMSHAFT position sensor has NOTHING to do with ignition timing. The only thing it does is time the fuel injectors on EEC-IV SFI engines. Ignition timing is controlled by the CRANKSHAFT position sensor.

 

[Ranger44]

Some diagnosis and testing needs to be done in order to fix this truck.

Thinking about it, a lean code would mean an air intake leak or lack of fuel, maybe a misreading HO2S.

A misfire would mean an inappropriate amount of fuel or ignition fault.

What thing do the 2 have in common? Fuel.

Some suggestions though......

1). Do try and run a fuel system cleaner through. Fuel systems do get dirty.

2). Check pressure at the rail. Maybe even check volume. A pump can deliver correct fuel pressure but not enough volume under load.

3). Just do a general, yet thorough, visual inspection of the fuel system. Have a stethoscope? Listen to each injector with the engine running. Do they sound about the same? There should be a nice even click click, and have about the same tone. You can measure the resistance of each injector. They should all be within .04 ohms of each other. Look at the connectors, wiring.

4). As I mentioned above. The CAM PS times the injectors. These are prone to wearing teeth and failing. Have you been hearing is squeal? Chirp? How many miles do you have on the truck?