Random Misfiring Engine S60 03

Post by **abscate** » 23 Mar 2019, 09:39

So cylinder 1 and 2 aren't firing, but coils and plugs are apparently good.

Evaluate signal to fuel injectors 1 and 2

Evaluate wiring to coils 1 and 2

You can try swapping fuel injectors , too, but it's more work than coils

Walru5 · Post by **Walru5** » 23 Mar 2019, 09:55

abscate wrote: 23 Mar 2019, 09:39 So cylinder 1 and 2 aren't firing, but coils and plugs are apparently good.

Evaluate signal to fuel injectors 1 and 2

Evaluate wiring to coils 1 and 2

You can try swapping fuel injectors , too, but it's more work than coils

I tried swapping injectors on those same cylinders before because I noticed if I unplugged the 1 and 2 injectors nothing happened but unplugging 3,4,5 changed the idle. I forgot about that so I didn’t mention it before sorry.

Post by **oragex** » 23 Mar 2019, 10:49

So the cyl 1,2 misfire even with good coils. That would meant it's not the coils but the injectors on cyl 1,2 (assuming the spark plugs are the correct ones, the kind with 3 or 4 electrodes https://www.rmeuropean.com/Images/BigPi ... FG14-2.jpg

Still it's just a supposition. May try some used injectors (green ones) from the junkyard (not worth buying new and chinese refurbished ones are risky)

Not related but while there, also look at the air filter box thermostat on your non turbo engine www.youtube.com/watch?v=gOx3Q8vqoz4

EngineeringBloke · Post by **EngineeringBloke** » 23 Mar 2019, 11:21

mrbrian200 mentioned that there are coil pack grounds that can get poor electrical connectivity. I think in addition to the bolt that holds each coil pack, that there are two other ground bolts near the coil packs. One is for coils 1 and 2 while the other is for 3, 4 and 5. The additional grounds are clearly shown on page one of the following PDF:

https://www.davebarton.com/pdf/5Cylinde ... sGuide.pdf

Undo these ground bolts and check for rust or corrosion. The left back one may be affecting your coils 1 and 2 operation.

Also check to make sure the coil pack wires have not been crimped by the engine top plastic cover. Look for breaks in the plastic corrugated tubing that covers the coil pack wires.

Walru5 · Post by **Walru5** » 23 Mar 2019, 15:13

EngineeringBloke wrote: 23 Mar 2019, 11:21 mrbrian200 mentioned that there are coil pack grounds that can get poor electrical connectivity. I think in addition to the bolt that holds each coil pack, that there are two other ground bolts near the coil packs. One is for coils 1 and 2 while the other is for 3, 4 and 5. The additional grounds are clearly shown on page one of the following PDF:

https://www.davebarton.com/pdf/5Cylinde ... sGuide.pdf

Undo these ground bolts and check for rust or corrosion. The left back one may be affecting your coils 1 and 2 operation.

Also check to make sure the coil pack wires have not been crimped by the engine top plastic cover. Look for breaks in the plastic corrugated tubing that covers the coil pack wires.

Okay so I swapped the coil harnesses on 1 and 2 just to be sure and it fixed the misfire temporarily. I drove the car on the highway and everything but about a half hour later I went to the store and on the way it started misfiring again. I scanned it and got a misfire code for cylinder 2. I swapped the cylinders coil with the first one and then the misfire code swapped to the 1st cylinder so I’m assuming it’s a bad coil now and I should just replace that one?

Thanks for all the help guys it’s getting better as we go.

Post by **abscate** » 23 Mar 2019, 16:08

Yeah, get a new coil on 2.

Look at the date code on your coils, are they from 2003?

Time for new ones if you don’t want fuss.

Buy four more, sell three working used ones, keep one spare

Walru5 · Post by **Walru5** » 23 Mar 2019, 16:18

abscate wrote: 23 Mar 2019, 16:08 Yeah, get a new coil on 2.

Look at the date code on your coils, are they from 2003?

Time for new ones if you don’t want fuss.

Buy four more, sell three working used ones, keep one spare

I’ll definitely check and then do that if they are.

Walru5 · Post by **Walru5** » 23 Mar 2019, 17:04

Car is fixed and working perfectly again. Thanks for all the amazing help and suggestions. I’m just going to buy 4 more coils as someone said above since all my coils are so worn I can’t even read the part numbers anymore.

Post by **oragex** » 23 Mar 2019, 22:05

Good news. Those Duralast coils are not well regarded, the genuine ones are the same as Bosch, can be hand at a junkyard for not much www.youtube.com/watch?v=uHLgXQo6E9c