Ongoing misfire issue P0303

[still_life127]

Ok so here it goes. I ran a quick search but couldn't really fine an answer for my specific problem.

I'm gonna give you guys a little run down so I can try to cover everything.

It all started last week, with the car running rough and the exhaust sounding weird... Sounds like a shitty old Cadillac or truck with an exahust leak, but there is none that I could find that night.

Next day I get a CEL and pulled code P0303 - Cylinder 3 misfire.

Car is completely stock, Aside from suspension and brakes. Even stock tune currently loaded. (Been loaded for a few months.) 76k On clock.

Here's what i've done so far to no avail.

New spark plug, reset engine codes. No Change. P0303 Comes back.

-Spark plug looked foul, covered in black soot. Rich burn?

New Coil Pack, reset engine codes. No Change. P0303 Comes back.

New Injector, reset engine codes. No Change P0303 Comes back.

Pulled pig tails off injector and coil pack. Both getting 13V.

What else could it possibly be? Vacuum Leak? Wouldn't that give me a white/scorched spark plug/lean burn as well as different Service code?


Thanks in advance for any incite you guys can give.

 

[killr3v]

Leaking valve seals, worn camshaft or follower lobes or worn piston rings would cause a misfire. Can you post a video of the noise? Since you already ruled out fuel and spark, it's most likely mechanical

Sent from my SGH-M919 using Tapatalk

 

[michael.konor]

New Coil Pack, reset engine codes. No Change. P0303 Comes back.

New Injector, reset engine codes. No Change P0303 Comes back.

Pulled pig tails off injector and coil pack. Both getting 13V.

Though you've done a good job of troubleshooting, you missed one critical item. Sure you have a good input voltage going to the injector and COP (focus on the COP), but do you know if they're actually firing?

In order to fire, they've got to receive the pulsed "ground" signal to complete the path. For the injector, there's a kit you can rent from an auto supply place that has a small light that'll pulse when you run the car. Don't know if they'll work with a COP, never tried. But I don't see why not, since they work on the same principle.

 

[still_life127]

Thanks for your replies. What is this tool called?

 

[michael.konor]

They look like this:

http://www.ebay.com/sch/6000/i.html...e+Signal&_dmpt=Motors_Automotive_Tools&_rdc=2

 

[86GT351]

Tool is called a Noid Lite

 

[still_life127]

Tool is called a Noid Lite

Can you confirm that it will work for testing the electrical pulse for the coil pack? If it turns out I'm not getting the electrical pulse, what am I looking at replacing? The ECM?

Also, whatever happened to you man? Are you still in my area? (margate)

 

[86GT351]

Can you confirm that it will work for testing the electrical pulse for the coil pack? If it turns out I'm not getting the electrical pulse, what am I looking at replacing? The ECM?

Also, whatever happened to you man? Are you still in my area? (margate)

Call me. Number is still the same.

 

[still_life127]

Update -The car passed the noid light test (on both Coil and injector plugs), compression test (highest being 190, lowest being 180), and leak down test. So what does that leave me? Cam lobe and/or cam follower? Vacuum leak?

I'm thinking im going to pop the intake manifold off and inspect that as well as gaskets for potential problems next. If nothing shows up there I'll moved to the valve cover and see if I can find anything obvious there. Any other suggestions?

 

[Kalatrax]

It very well could be a valve not opening enough or at all. Pull the covers and take a peek. Shouldn't be too hard. You may also try swapping an injector and coil from a known good cylinder over to that one. I know you replaced all that but it is possible to get a bad one out of the box.

 

[kampendmk]

my fix

I had the same problem switch gas stations i was getting po300 po305 po303 from usa gas switch to arco code went away i`m running 91 oct

 

[86GT351]

I had the same problem switch gas stations i was getting po300 po305 po303 from usa gas switch to arco code went away i`m running 91 oct

WOW! HAve not seen that name for years.

Steve. Pull the Valve Cover first. Much easier to do than the Intake.

 

[still_life127]

I had the same problem switch gas stations i was getting po300 po305 po303 from usa gas switch to arco code went away i`m running 91 oct

Ive tried different gas. If it were in multiple different cylinders, I would think along the lines you mentioned, but its always cylinder 3. No matter what I change and how many times I clear it, the same P0303 code always comes back.

WOW! HAve not seen that name for years.

Steve. Pull the Valve Cover first. Much easier to do than the Intake.

Yeah, I agree. Gonna try that first. Doing it here in a few mins.

 

[still_life127]

Well... Found my problem



So it leaves me with the question - Does the camshaft have to be replaced do to the scratches on the lobe?



And what about this? (Damaged piece that the roller presses against, not sure what it's called)

 

[Kalatrax]

Well... Found my problem



So it leaves me with the question - Does the camshaft have to be replaced do to the scratches on the lobe?



And what about this? (Damaged piece that the roller presses against, not sure what it's called)

As suspected. Not terrible though. How deep are the scratches in the cam? If they are just rough and not deep you may be able to get away with hitting the lobe with an emery cloth and reusing the cam or pickup a used one from someone on here for cheap. The "piece it presses on" is a lash adjuster. Make sure you change your oil to get all those broken bits of the lash adjuster out.
Lash adjuster-
http://www.shopfreedomracing.com/68L-54L-46L-3V-Hydraulic-Lash-Adjuster-5L1Z-6500-A-5L1Z-6500-A.htm
Cam follower-
http://www.cjponyparts.com/ford-cam...ign=shopping?gclid=COPSobP_p70CFROVfgodX2IAhQ

 

[her name is ponie]

I have stock set of cams you can have for shipping

 

[86GT351]

Steve. Once I see it in person I will confirm about the cam like we discussed last night. I can also get you the adjuster and follower local.

We will discuss it more later when you swing by the house.

 

[still_life127]

As suspected. Not terrible though. How deep are the scratches in the cam? If they are just rough and not deep you may be able to get away with hitting the lobe with an emery cloth and reusing the cam or pickup a used one from someone on here for cheap. The "piece it presses on" is a lash adjuster. Make sure you change your oil to get all those broken bits of the lash adjuster out.
Lash adjuster-
http://www.shopfreedomracing.com/68L-54L-46L-3V-Hydraulic-Lash-Adjuster-5L1Z-6500-A-5L1Z-6500-A.htm
Cam follower-
http://www.cjponyparts.com/ford-cam...ign=shopping?gclid=COPSobP_p70CFROVfgodX2IAhQ

Awesome, thanks for the info. I've gotta inspect it a little further when I get home from work today. I think I found all the broken pieces of the lash adjuster and follower sitting in the bottom of the head. Either way, i'll definitely change the oil.

I have stock set of cams you can have for shipping

Sweet, how many miles roughly? I may take you up on that. Or, I may say fuck it and do some Hot Rod Cams. We'll see what happens.

Steve. Once I see it in person I will confirm about the cam like we discussed last night. I can also get you the adjuster and follower local.

We will discuss it more later when you swing by the house.

Sounds good man, I'll see you later today.

 

[eighty6gt]

Save the cam money for a TVS 2300. Less headaches.

 

[86GT351]

Will be digging into this later in the week. Got Steve a rocking Deal on a brand new set of cams with followers, etc. Just need to order some Valve Cover Gaskets and some misc goodies. Should be digging in on Thursday