hey guys.....my turn.

 

 got an 05 volvo s40. code 3502. no p-codes, just that one. car has a dead misfire. looking at data on scanner, i can see #5 cylinder misfiring. pull plugs, and they look shitty. install new plugs, and one coil on that cylinder, since they're all under the intake. re-start, and same shit.

 

 this is a dead miss, single cylinder. i swapped injectors, and i ran compression test on that hole. it was 150psi cranking. can't get running compression due to intake being off. none of my shit has any really comprehensive diagnostics on that code. i know there;s a couple of you that're shop owners, and a few others that work in the field.

 

 what the eff am i missing?

Is that coil getting power?  Might want to check continuity in the wiring...

 hey guys.....my turn.

 

 got an 05 volvo s40. code 3502. no p-codes, just that one. car has a dead misfire. looking at data on scanner, i can see #5 cylinder misfiring. pull plugs, and they look shitty. install new plugs, and one coil on that cylinder, since they're all under the intake. re-start, and same shit.

 

 this is a dead miss, single cylinder. i swapped injectors, and i ran compression test on that hole. it was 150psi cranking. can't get running compression due to intake being off. none of my shit has any really comprehensive diagnostics on that code. i know there;s a couple of you that're shop owners, and a few others that work in the field.

 

 what the eff am i missing?

 

I had a similar problem once.   The cam lobe on the intake was ground perfectly round.   Apparently some debris or something had caught in that oil journal and no oil wound up on that lifter.  No lube, ground cam, no gas, no fire. 

 

I would also look at the wiring on the coil pack, it's possible the spades inside the connector plug are corroded or that it's broken somewhere else.

i've got spark. i was able to confirm that with the intake off, just cranking. i forgot about cam lobe wear....it's been so dam long since i've dealt with that........

If you had compression I would think the cam is fine...  You swapped injectors but did you check the injector wiring?

checked injector pulse, and it's good.

You swapped the 5 coil, have done nothing with injectors other than test power coming to them? Correct?

Clogged injector or fuel rail?

 

I slept at a holiday in.

You swapped the 5 coil, have done nothing with injectors other than test power coming to them? Correct?

Clogged injector or fuel rail?

 

I slept at a holiday in.

no. when i replaced plugs, i tossed a new coil pack on #5, 'cause the intake's gotta come off to do them. still had misfire there. used a noid light to test injector pulse, which was present. yanked the fuel rail, and swapped #'s 4 and 5 injectors. the misfire remained on #5 as per the scanner data showing me the misfire counts

and this one's pissing me off, 'cause i can't find info.....and it's making me feel really stupid.

Can you ck fuel rail?

Just out of curiosity, I'd pull the wires on #1 and make sure the scanner is correctly identifying the misfiring cylinder since you seem to have eliminated everything on 5.     You would think it'd throw a P0305 DTC but I am not familiar with Volvos ecms.

 

It doesn't appear to be the injector seals since you swapped and it stays at Cyl 5, but did you try shooting some carb cleaner or ether near the injector while it's running to see if idle changes?

Just out of curiosity, I'd pull the wires on #1 and make sure the scanner is correctly identifying the misfiring cylinder since you seem to have eliminated everything on 5.     You would think it'd throw a P0305 DTC but I am not familiar with Volvos ecms.

 

It doesn't appear to be the injector seals since you swapped and it stays at Cyl 5, but did you try shooting some carb cleaner or ether near the injector while it's running to see if idle changes?

this would be my next step also, the ecm uses the crank-sensor to determine which cylinder is misfiring, if its a dead miss or multiple misses it can be very inaccurate, ive seen cars with a dead mis throwing code p0301 indicating a cylinder 1 misfire but in reality its cylinder 3 misfiring, when it comes down to it the computer is really just taking a educated guess in which cylinder is missing  

 

next if you have diagnosed that its actually cylinder 5 i would check timing, and also perform a cylinder leak down test, just because you have good compression doesn't mean the cylinder is completely sealed, if all those check out you might want to take a look at the ecm last, this is the most unlikely but still a probable cause 

i'm a dumbass. fucking stupid stupid stupid mistake.

 

scanner id'd misfire #5. most every car that would mean #5 cylinder. volvo apparently didn't get that memo. volvo computer means #5 in the firing order. that would be cylinder #3.

 

 i KNEW i was overlooking something stupid, and now i'm pissed off at myself for this.........

I used to hate working on my Volvo.  I don't speak Swedish.

 

Glad you found it.  

i'm a dumbass. fucking stupid stupid stupid mistake.

 

scanner id'd misfire #5. most every car that would mean #5 cylinder. volvo apparently didn't get that memo. volvo computer means #5 in the firing order. that would be cylinder #3.

 

 i KNEW i was overlooking something stupid, and now i'm pissed off at myself for this.........

 

Ah, measurement error.  Cool, at least you found it.