Cold Misfire Codes P0300 + P0303

[Skot53]

For the last 3 Months. Every third cold startup or so, I get a misfire code on Cylinder #3 (P0303), and twice or three times gotten a "Multiple Cyl Misfire" (P0300).


Some history:
Car has 144K
Always gentle warmups, waiting 20 seconds for idle to slow from 1500 before moving.
Stock Tune, Filters, FMIC, the whole deal.
Replaced spark plugs when Misfire codes started (Volvo OEM)
Traded Coilpack #3 and #1 to see if problem "moves" with part, to no avail.

Car doesn't buck for seem like it's misfiring at all, MIL usually comes up at 15 MPH.

Could this be a bad knock sensor? Your input is appreciated.

[StealthyS60R]

A misfire is determined by the crank sensor realizing that there has been no crank acceleration for a particular power stroke event. Since you have already ruled out the coil and plug its time to move onto other causes.

It could also be a sticky fuel injector. To rule that out swap the 1 and 3 fuel injectors as well.

If the problem stays on 3 then its time to start looking at the electrical connectors, wiring and the coil driver assuming the R has one.

[Skot53]

Thanks for the input, Tony. I was going to look there next.

[Skot53]

Ended up being a soiled air filter. Yeah, flippin' random. Hope everyone's problems are so easily fixed!

[850arrrsaylikepirate]

Ended up being a soiled air filter. Yeah, flippin' random. Hope everyone's problems are so easily fixed!

So was the MAF dirty too??

[Skot53]

Nope. I think it was just non-laminar airflow across the MAF causing misfires during start up. Problem is gone. (OEM filter)

[850arrrsaylikepirate]

Cool and good to know.

[VolvokidS60R]

Ended up being a soiled air filter. Yeah, flippin' random. Hope everyone's problems are so easily fixed!

ok so...... Yea thats FLIPPING WEIRD!!!!!!!
In all my years at volvo iv never herd of this, but hay there is a 1st for ever thing right..?

[Skot53]

Could have been involved with the change of the seasons too. Weird electrical and building fitment issues come and go with the heat and freeze of the seasons at my work, too. I'll let you guys know if it comes back.

[Skot53]

Yep. Came back. Thinking it may be a fuel issue. Dunno when the last time the fuel filter was changed, so I'll start there, and work my way to injectors. Changed the spark plugs recently when this stuff first started, so that's not it.

Also, going to check the MAF again to make sure it's clean.

[garbergtsi]

Make sure you do a leakdown test stone COLD!
it may be time for valves? 04's were bad for those

[Skot53]

Thanks for the suggestion, but I think that's pretty far down the list. The car doesn't smoke or do anything else screwy (like a car with bad valves does). I'll start with sensors first.

[garbergtsi]

How many 04's with bad intake valves have you worked on? I have had quite a bit and never have seen one smoke or anything.

Just a suggestion though...

[Skot53]

Again, thanks for the suggestion. I've only has experience with VWs and their valve stem seals that wear out, causing smoke. This is my first Volvo. I'll take it into a shop if I can't get to the root of the trouble. Thanks!

Bought some LubroMoly fuel system cleaner and MAF cleaner... we'll see how it goes.

[Skot53]

After I cleaned the MAF, the car runs much smoother at idle now. I think that may have been the issue. (No CEL yet, either) When I replaced the air filter, I should have cleaned the MAF, I think hat would have taken care of the problem. It was a bit dusty in there (nothing too big, though). I guess there's a good reason to keep the foam sock on the stock air filter.

Thanks for you help everyone! I'll keep you guys posted if it comes back.

[58Ford2]

Scott, What are you using to read your codes? My cheapy from Harbor Freight wont list them.... PIA!

[inteller]

because to get good codes you need DICE. Those are just generic mandatory codes.

[VolvokidS60R]

Check all 5 coil packs for cracks. if find any crack of any kind replace. also you should be your head tested. i had a cust car with cold miss fire and come to find out it had a slow cooland leak into cy3.

[Skot53]

Scott, What are you using to read your codes? My cheapy from Harbor Freight wont list them.... PIA!

Scangauge II. It was $170 from iPd, but it helped me find an evap fault (bad gas cap :rolleyes) within the first week of ownership. If you want me to scan some codes for you, I'm totally willing to pop over after work.

Check all 5 coil packs for cracks. if find any crack of any kind replace. also you should be your head tested. i had a cust car with cold miss fire and come to find out it had a slow cooland leak into cy3.

Already checked the coils, they look fine. When the problems started, I swapped #1 for #3 to no avail, and inspected all of the coils closely (funny because I just posted about some cracked coils on VW and Audis). I'll keep an eye on things. Thanks again for the help guys!

[VolvokidS60R]

well youy know any bernt spots fail coiles also.
but if no fix id start lookin into a head gasket test like this
http://www.matcotools.com/ProductImages/AC560000.jpg
http://www.matcotools.com/Catalog/to...ype=T&cat=2477
i bet if all else fails check head gasket

[Skot53]

well you know any burned spots indicate failed coils also.

Yeah, I used to have a VW GTI and and Audi TT, i've heard all of the horror stories about "Coilpacks". Coilpack Failure Log

Thanks for your help, Nick. I'll keep everyone posted. It's been a long Labor Day weekend with many hours of driving, and may hours of sitting (which tends to trip the code), with NO CODES! So, I think this may be resolved.

[StealthyS60R]

Could just be a sticky fuel injector. Try a can or two of fuel injector cleaner. If that doesn't do anything for you and you feel up for it, pull the fuel rail and swap around the injectors to see if that moves the misfire. If it does then replace the bad injector.

I don't think it has anything to do with your maf or filter since there is no way those items would cause just one cylinder to fail on a power stroke.

[Skot53]

Could just be a sticky fuel injector. Try a can or two of fuel injector cleaner.

I put in a can of LubroMoly Fuel System Cleaner when I cleaned the MAF, then filled up at Chevron.

I don't think it has anything to do with your maf or filter since there is no way those items would cause just one cylinder to fail on a power stroke.

Thanks for the input. I'm getting a variety of codes at the moment, mainly P0303- but also 0300 (multi) and 0301 (#1 misfire) as well.

[StealthyS60R]

Does it happen at lower fuel levels? If its not purely electronic I wonder if air is being sucked into the fuel pump intake and sending air bubbles down the fuel rail which could also cause a rash of misfires.

[Skot53]

It came back again the other day... Starting to get a bit annoying. It would help if I didn't work so much so I could bring it into a shop.

Does it happen at lower fuel levels?

You know what... maybe it does!!! It does seem to go away for a few days, then come back when I'm at lower fuel level. Has that happened to you before? I did replace my fuel level sender, but I'm pretty sure I put it together correctly.

edit: it happens at all fuel levels. Empty, full, half tank, doesn't matter.

[StealthyS60R]

Well Skot, that hasn't happened to me on my R, but I have ran another fuel injected car low on fuel before and experienced a flurry of misfires that occur when you start sucking air into the fuel pump.

Just a scientific wild assed guess based on thinking about all the possible causes could be leading to your particular symptoms, lol.

[Skot53]

Drove 80 or so miles this weekend... Still no CEL . Called the local dealership asking about the Fuel Pump Recall. The Service Manager claims that the fuel pump problem will not cause a CEL, and I pretty much agree. All of the internet research that I've seen, it's just the fuel smell. Made an appt for a week from now to check on the fuel pump to make sure it isn't leaking... though I may cancel. I really don't like other people touching my car.


edit: I did end up canceling. I hate dealerships. At this time, my car is no longer eligible for the recall due to mileage.

[Skot53]

It hasn't gotten better or worse, but I figured that I would update.

I've just been leaving the CEL on, not caring, due to other issues making the CEL come up just about every day. Search my name on these forums for more info.

I took it into an independent Volvo mechanic to get a software update. I was having troubles with the Fuel Leak Diagnostic Pump, and I figured I'd take it in, since getting to the pump is such a PITA. When they updated the firmware, the service writer informed me that the P0303 code was possibly due to software as well, since I told him that I changed the spark plugs and moved the coil- which didn't help at that time. He did not mention anything about valves, though he WAS just a service writer, the mechanic didn't mention anything either... I'll update this thread in a week or so with a conclusion.

[Short Circuit]

With 144K miles, your coils are toasted 2x over. Jeez man, get 5 new coils from IPD in your own back-yard and solve this problem once and for all!

[Skot53]

With 144K miles, your coils are toasted 2x over. Jeez man, get 5 new coils from IPD in your own back-yard and solve this problem once and for all!

Would you say, perhaps, that they have a Short Circuit?

BTW, the car now has 152,500 miles. She likes to be driven! I was waiting for the iPd R coil debacle to be over, and for them to be re-released on their website. The P0303 CEL came back on again this morning, shortly after start-up. Swede One Auto Werks treated me really good yesterday, so I may lean to them for further diagnoses. (cold leak down test, et al)

[ari951]

With 144K miles, your coils are toasted 2x over. Jeez man, get 5 new coils from IPD in your own back-yard and solve this problem once and for all!

+1. Fixed my problem.

Also, I cannot remember the code (P2303?), IDK, but the recall for replacement of fuel pump fixed this code.

[Warpedcow]

Always gentle warmups, waiting 20 seconds for idle to slow from 1500 before moving.

Waste of fuel. Just drive gently (low boost and low RPM) until things start to warm up.
The Car Talk guys got this one correct!

[Skot53]

20 seconds isn't THAT long... Buckle seat belt, plug in iPod, turn on wipers. it's usually calming down by then. It's not like i let it run outside for half an hour.

[Skot53]

The CEL has turned off as of yesterday after work. I've noticed that the car has a very slight stutter when it is doing the 20 second warmup in the morning and after work, which very well could be causing the code. I am waiting for iPd to reissue their HD R coils (due mid-february), and I will replace them all then, and move injector 3 to position 1, just incase that is the root problem. I am really stating to think that it is the coils and not the injectors. The car starts the same regardless of how long it has been sitting. If it WAS a stuck or leaky injector, it would cause rough, longer cold startups, right?

BTW, the Volvo code that came up when I had my software update was "ECM-3533 (startup)".

[Warpedcow]

20 seconds isn't THAT long... Buckle seat belt, plug in iPod, turn on wipers. it's usually calming down by then. It's not like i let it run outside for half an hour.

Still a small waste. I'd rather "waste" my gas enjoying WOT when the light turns green than sitting in my garage. I plug in my phone (Trapster), buckle up, tune the radio, hit the garage door button, then start the car.