P303

pryornfld · #1 04-07-2005, 07:53 AM

Me Again,

Seems like I get about 2-3 months of problemfree driving and bam, another bunch of problems. About 2 weeks ago , had to get the front cover replaced because of a coolant leak. No more leak and I'm very happy. However yesterday I had a misfire code of P303(#3 cyc). It only happens intermittently and only when starting ,after you drive off it goes away. It doesnt matter if the engine is hot/cold, it will happen randomly.

I did have a mechanic that I thought I could trust, but apparently not. I found out yesterday that the plugs are the same ones from about 3 years ago, and he was suppose to have changed them. SO I will be replacing the plugs and I need to know the layout of where all the plugs are and in what order.

If you have any info, it would greatly be appericated.

Thanks
Pryornfld

P.S: Anyone know what the trade in value of a 96 GL would be??

DRW1000 · #2 04-07-2005, 08:26 AM

If you have the same plugs as 3 years ago and they were due to be changed at that time my first guess for your misfire would be a bad plug.

What makes you so sure that the plugs were not changed? I have heard of independant mechanics simply using non-platinum (or non-double platinum as the case may be) as replacements to offer a better price than the dealer but the downside is that they wear out quickly. Charging for a job they did not do is unethical. (gross understatement here)

What exactly do you need to know? What do you mean by layout?.

pryornfld · #3 04-19-2005, 10:59 AM

Quote:

Originally Posted by DRW1000

If you have the same plugs as 3 years ago and they were due to be changed at that time my first guess for your misfire would be a bad plug.

What makes you so sure that the plugs were not changed? I have heard of independant mechanics simply using non-platinum (or non-double platinum as the case may be) as replacements to offer a better price than the dealer but the downside is that they wear out quickly. Charging for a job they did not do is unethical. (gross understatement here)

What exactly do you need to know? What do you mean by layout?.

Sorry so late getting back. Was away on vacation. Anyway I know the plugs were not replaced as they are too rusty and worn to be only 4 months old. Had the plugs replaced over the holidays and was problem free until today. Another misfire!! So now the plugs and the plug wires,fuel filter,and air filter all replaced. What else could cause the misfire. Last time it was CYC #3, but haven't read the codes today so not sure what CYC is the problem.
What should be next on the list??

l-m tech · #4 04-19-2005, 11:30 AM

Quote:

Originally Posted by pryornfld

Sorry so late getting back. Was away on vacation. Anyway I know the plugs were not replaced as they are too rusty and worn to be only 4 months old. Had the plugs replaced over the holidays and was problem free until today. Another misfire!! So now the plugs and the plug wires,fuel filter,and air filter all replaced. What else could cause the misfire. Last time it was CYC #3, but haven't read the codes today so not sure what CYC is the problem.
What should be next on the list??

your egr ports are stopping up sending all egr flow to #3 cyl.causing a lean misfire.that is where i would start next.

DRW1000 · #5 04-19-2005, 11:37 AM

I agree to check the EGR flow for too much to that cylinder (or too little to the others).

Other things to consider

What about the coil pack? The easiest thing would be to ensure you have spark to that cylinder.

I would also not rule out fuel injectors just yet.

pryornfld · #6 04-19-2005, 11:45 AM

Quote:

Originally Posted by DRW1000

I agree to check the EGR flow for too much to that cylinder (or too little to the others).

Other things to consider

What about the coil pack? The easiest thing would be to ensure you have spark to that cylinder.

I would also not rule out fuel injectors just yet.

I think the next thing to try would be the coil pack as it seems to be an intermittent problem( mind you a real pain in the a$$) and I was told it could very well be this as it happened several times on 3 different cyc.
Does this sound like it could be the coil , as it has happened on different cyc, or could it be something else?? What would be the easiest way to check the coil?

pryornfld · #7 04-19-2005, 02:05 PM

My wife just made a trip to the market and said that when she started the van, the check engine light was out and didn't come back on. So the misfire is definately a random act. What are the possible problems leading to this. It has been ungoing over the last two years, but recently (this year) about 3 times already.

DRW1000 · #8 04-19-2005, 02:16 PM

Just thought of it............One way to check the EGR is to disconnect the vacuum line to the EGR (and plug it) This will cause a different error code but it should run smoother if the EGR gasses are the problem. There should be no EGR flow at idle either so if your problems occur at idle then it may not be the EGR or the EGR is sticking.....

To check the coli pack I would purchase a ignition tester. I got onew for a couple of bucks. Basically you connect your spark plug cable to it and it has an adjustable gap. The ohter end is grounded. When you start the car you can see if that plug is getting ignition. There are also inductive pick up testers too.

pryornfld · #9 04-19-2005, 02:26 PM

Quote:

Originally Posted by DRW1000

Just thought of it............One way to check the EGR is to disconnect the vacuum line to the EGR (and plug it) This will cause a different error code but it should run smoother if the EGR gasses are the problem. There should be no EGR flow at idle either so if your problems occur at idle then it may not be the EGR or the EGR is sticking.....

To check the coli pack I would purchase a ignition tester. I got onew for a couple of bucks. Basically you connect your spark plug cable to it and it has an adjustable gap. The ohter end is grounded. When you start the car you can see if that plug is getting ignition. There are also inductive pick up testers too.

What do you do if the CEL went out by itself??

wiswind · #10 04-19-2005, 10:52 PM

Double check to make sure that the CEL lights up for a short time when you start the car....just to be certain that the bulb did not burn out. If the bulb is fine, and the CEL went out......that means that you have had a good number of cycles without a problem.

The cylinders that normally give a missfire due to clogged EGR ports are Cylinders #1 and #4.....as they are the farthest from the EGR valve.....and the last to clog. Cylinder #1 is on the back of the engine....passenger side. Cylinder #4 is on the front of the engine....passenger side.

If the CEL comes back on.....get the codes read again....just to be sure of the problem.

pryornfld · #11 04-20-2005, 08:40 AM

Quote:

Originally Posted by wiswind

Double check to make sure that the CEL lights up for a short time when you start the car....just to be certain that the bulb did not burn out. If the bulb is fine, and the CEL went out......that means that you have had a good number of cycles without a problem.

The cylinders that normally give a missfire due to clogged EGR ports are Cylinders #1 and #4.....as they are the farthest from the EGR valve.....and the last to clog. Cylinder #1 is on the back of the engine....passenger side. Cylinder #4 is on the front of the engine....passenger side.

If the CEL comes back on.....get the codes read again....just to be sure of the problem.

Should I still be concerned with the Misfire or let it go and see if it comes back on?

wiswind · #12 04-20-2005, 11:58 PM

It is kind of hard to troublshoot without a code.

I replaced a lot of things chasing down a misfire this past summer......at 149K miles.....and over time....much of what I replaced eliminated future problems.....a few things were clearly marginal....

However, the root cause of my misfire was crud inside the fuel injector caps. I finally got a code for cylinder #1......which I quickly determined to be the injector.....but all the injectors needed the cleaning....a very cheap fix.....doing it myself.

ogre73 · #13 04-21-2005, 02:10 PM

Also see my thread here. http://www.automotiveforums.com/vbul...d.php?t=389340
I had the intermittent misfire on cylinder 2 that got worse when the engine was warm (thermal expansion of the white plastic allowed the crack to widen and the coil to arc, hence the brown around the crack) or under load (more voltage = greater chance to arc).

timmytaurus · #14 12-03-2011, 10:43 AM

2002 Windstar it's mid engine, just behind the intake; follow the spark plug wires. Very, very easy to change, only need minimum skill on cars. I'd buy the replacement first so you have it right there when you pull the old one. Look at the new one to see where the 7mm hex bolts are. First reach in (A little tight, but arms will fit around both sides of engine) an undo all three hex bolt, it will make it easy to disconnect thin wire connector and plug wire if you can move it around. Then unplug thin wire connector, I had to use needle noise in order to pinch the little tab that released the plug. Move the new coil back there pune plug one at a time, plug into the new immediately to get the righ socket. Pull old coil out when done. Plug in the thin wire connector. Move new coil over mounting screw holes. I had to unplug a few wires one at a time again to get them to lay right in order to get the coil to sit right. Put in hex bolt Very Very lightly! only snug, barly snug, or you'll bust it. Start the car and Vrrroom! runs like it's brand new! I had codes P0303, P0304, (Misfire 3&4 plug) from the free computer read at Auto Zone- along with P0171 & P0172. All codes gone after this coil replace. I don't know why Ford put such a crapy part that fails on there cars. Runs like a champ now. Good luck. Part $65 at auto zone.
Tim O.

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