Injector issues

[Geoff69a1]

Morning all.New here so be gentle with me.I recently acquired a 2001 xc70which has been running fine until I appeared to drop a cylinder on the way to the store the other day.Took it to autozone and their meter threw out the code for #3 injector faulty.I assumed that #3 would be the middle one of the 5 but with Volvos nothing is sure ,so was I right.Anyway I installed a replacement but it has not cured the problem,hence this post.My question is,does anything need to be reset to tell the computer that a replacement has been done or should it be automatic.
Another code that came up was the dreaded evap leak.This I could probably fix if only I could find the purge valve which is likely the problem.I have looked down the drivers side of the fan where someone suggested it would be but no luck yet
If anyone cane help me out with either problem I would be very grateful.
Geoff.

[billr99]

Well, # 3 is in the middle so you can go left-to-right or vice versa and it makes no difference as #3 is the same either way. But in all seriousness, the cylinder numbering starts at the front of the engine or in the case of P2 Volvos, the end with the cam belt.

I don't think that an injector error needs to be cleared. So if you still have the problem take a good look at the injector wiring and make sure there are no faults. At the minimum, the sheathing is known to breakdown over time so perhaps you have short going to that injector.

Good Luck,

Bill

[Iroll_]

Has the car been using coolant?
I do not want to be an alarmist but cylinder 3 has a tendency to burn valves, generally if the incorrect grade of gas has been used over a long period of time.
It's possible to check the duty cycles ( via a code reader), of the injectors to see if the other injectors are working correctly too

[8pack]

When you say "dropped a cylinder" I assume you mean running really rough. Was the CEL flashing? I would have guessed it would show a misfire code as well.....those Autozone boys try hard...but...

Are you sure it is not a coil pack. Symptoms would be very similar.........and it is another explanation on why the problem has not gone away..and a cheap fix on top of that....

You should keep a spare coil pack in the car anyway. It is a 5 minute side of the road fix if one goes bad. If it were me I would buy one and try it unless I was sure it wasn't something else and if it wasn't the problem I would have a spare coil pack for the future.

[Astro14]

Swap coil packs. Pick a cylinder and swap with cylinder 3. Takes about 15 minutes. See if your misfire moves...if it does, buy a new Bosch coil pack on Amazon for $50. If not, take a good look at your wiring. I've still got all 5 OE injectors in both cars. They're pretty reliable. But coil packs fail now and then...

[Geoff69a1]

First,Thanks for all your replies. I have the actual printout in my hand from a/zone and the code thrown was p0303,Misfire emission level from cyl 3 with 3 way catalyst damage from cyl 3.I don't really know what this actually means but the recommendation is replace injector.Any reccs based on that?
Geoff.

[Astro14]

P303 is a no. 3 cylinder misfire.

There are many potential causes for a misfire: injector, plug, coil...

But the most likely is the coil. Swap coils, if the misfire moves, you've found the problem.

Until you try that, we are all just guessing.

Coils are common failure points in this engine. If you need a coil, the dealer wants $90, and I would just get it here:http://www.amazon.com/Bosch-00117-Ig...dp_o_pd_nS_ttl

[hoonk]

Misfire emission level from cyl 3. Any reccs based on that?

check compression on #3 cylinder (maybe all of them just for fun) Compression has to be at least 100 psi for a cylinder to run. Dont worry uneven readings, sometimes its hard to get an accurate number w/out having throttle open all the way.
If compression (and spark plug) is ok, swap #3 coil to another cylinder and start engine to determine if misfire moves to another cylinder
(you can do the same thing with a bad injector but they rarely have a problem, and they take longer/messier to move around)

If not compression, or coil, (or spark plugs!) then test injectors.

Always make sure the spark plugs are in good condition (have been replaced with an appropriate brand in the past 50,000 miles or so, and are not damaged/fouled from misfiring)

Yes without a scan tool of your own it will be hard to tell what cylinder the misfire has moved to (if it does)

If the engine is misfiring/running rough at idle you can try unplugging the injectors one by one to see which one creates the smallest idle drop (the throttle will try to keep the idle speed constant, even running on 4 cylinders)

[8pack]

P303 is a no. 3 cylinder misfire.

There are many potential causes for a misfire: injector, plug, coil...

But the most likely is the coil. Swap coils, if the misfire moves, you've found the problem.

Until you try that, we are all just guessing.

Coils are common failure points in this engine. If you need a coil, the dealer wants $90, and I would just get it here:http://www.amazon.com/Bosch-00117-Ig...dp_o_pd_nS_ttl

This is the cheapest and fastest thing to do before you do anything else. You need 2 torx bits and an 8mm socket....takes 15 mins tops as Astro said.

[Astro14]

One other thought: if the car is new to you, and you're going to swap coils around, just put new plugs in while you're there. I've used Volvo plugs only in my cars, buy them on line, dealer prices are crazy, but FCP Euro or IPD aren't bad.

Once the charge air pipe (the plastic pipe over the engine) is off (two clamps, I use a 7mm 1/4" drive socket vs screwdriver on those), then it's eight or ten torx bolts to get the cover off. T35 or T30, can't remember. I use a nut driver handle for those, too. Then a single 10mm bolt holds each coil in place. The wiring looms are likely brittle with age, be gentle in disconnecting them. Pop the coil out, change the plugs.

Swap coils, restart and get the code read.

See if the misfire moved. I'm willing to bet it's the coil, and the misfire will be where that coil now sits.

If not, well, you're eliminating the possible causes.