Help! Car is broken down. 00 V40 with BAD misfire

[ZVOLV]

Fixing my mom's 00 V40.

I was told that it had no power to accelerate and it would flash the CEL.

I told them to take it to the dealer. Dealer pulled the codes and said bad ETC and battery negative cable.

They swapped the ECT cleared the codes and topped off the coolant for a total of $400.

Took it back home and swapped the cable last night myself instead of paying $280.

Old plugs were blown out. 1 and 2 had a large gap and the pointy tip on the electrode was gone. I swapped the plugs. No change. Still misfires.

Now the car has a bad misfire and backfires thru the intake and exhaust at startup. I check fuel pressure and it was good. I checked cam timing and it was good. Just finished swapping the old cracked 100k timing belt too.

The V40 has coil packs on 3 and 4 and then plug wires coming of these coils for 1 and 2. Confirmed spark on 1 and 2, but when I tried to pull the coils and use a spare plug to check for spark the car wouldnt even start. It would start and run with either 1 or 2 plug wires disconnected.

I just restarted it and it misfires badly still. Backfiring too from intake and exhaust. Even some white smoke and steam from tailpipe but it went away.

I had to turn the car off because the cat just started to get red hot and smoky!

I am going to go back to my house and get my code reader and compression tester and then take it from there.

[745 TurboGreasel]

the pointy tip on the electrode was gone. I swapped the plugs. No change. Still misfires.

the pointy tip went somewhere.....

[vlvman]

If the cat is getting red hot it is running lean, sounds like a fuel problem to me. But first you said you changed the timing belt. If the timing is off it can cause backfiring and bent valves. Before you restart the car verify timing belt is correctly installed and all timing marks are lined up correctly.

[ZVOLV]

First thing I did when it came back from the dealer was change the negative cable. No change.

Then I changed the spark plugs. No change.

Checked the timing and replaced belt. No change.

How do you test the ignition coils?

Do they need to be grounded with the hold down bolt in order to fire? Is this a wastespark setup where 1 and 3 fire together and then 2 and 4 fire together.

[vlvman]

I think the coils need to be grounded to fire. Could there be another ground causing the problems? Here is a wiring diagram, I would check all the grounds for the fuel system.
The diagram is 50mb and will be slow to open.
http://pliki.mojevolvo.pl/volvotechi...ction_3_39.pdf

[ZVOLV]

The plugs from cyls 1 and 2 were rounded. Plugs from 3 and 4 still had their tips.

[vlvman]

Let us know what codes you get. Sorry I am not familiar with this engine.

[ZVOLV]

Originally Posted by vlvman

Let us know what codes you get. Sorry I am not familiar with this engine.

Just pulled the codes. P0300- Random/multiple cylinder misfire detected.

Cleared it and restarted the car. It was hard to start and once it did is misfires and throws the same code immediately.

[vlvman]

Look for carbon traces on the sides of the coil, especially around the main body of the coil.

[Need For Swede]

An old trick is to run the car in total darkness and look under the hood for sparks.

[KLowD9x]

Pull the coils.

Check for cracks.

Cracked? replace the coil.

Also, the tips being off of the plugs is normal. That means they are old as hell though.

The reason that the tips were off on the first two and not the second two is because of the "waste spark" ignition system on this car. Two plugs fire "forward" and the other two plugs fire "backward".

[ZVOLV]

Just did a compression test and its an even 150psi on all 4.

Coils are pulled and look fine. Both measure 2.6 ohms between the two pins.

Plugs are pulled and look OK.

How do you test the coils?

[KLowD9x]

Don't know, never tested them.

Also, LOL.

You have the plug wires for cylinders 1 and 2 mixed up.

The wires are marked with a 1 and 2. LOLOL.

[vlvman]

I bet thats the problem, firing order.

[ZVOLV]

Originally Posted by KLowD9x

The wires are marked with a 1 and 2. LOLOL.

Doubtful.

[ZVOLV]

I changed the plugs and didnt pull any wires of the coils so this wouldnt happen.

I doubt that is the case.

[vlvman]

Swap the plug wires position on the plugs and try it.

[KLowD9x]

Originally Posted by ZVOLV

Doubtful.

Then let me give you even more assistance with this.

Using your own picture.



So, as I said, your plug wires are crossed between cylinders one and two.

[moxy123]

A cracked coil might still show a good primary resistance and still arc. An arc would show up as dead cylinder not a back fire.

Timing of spark somehow. Is the back fire consistent?

Can it run with one plug wire pulled? If so try one at a time and see if the back fire clears?

[vlvman]

So KlowD9x you are saying one wire goes to cylinder 1 and the other wire goes to cylinder 4. which means he has the coils on the wrong plugs and they should be on the center two cylinders. So what is the firing order? 1342?
Edit; nevermind

[ZVOLV]

That was it. Starts up and runs smooth!

Now it throws a 300, 351, and 352 code...

[moxy123]

I believe it is against Turbobrick protocol to use his own evidence against him.

[KLowD9x]

Originally Posted by vlvman

So KlowD9x you are saying one wire goes to cylinder 1 and the other wire goes to cylinder 4. which means he has the coils on the wrong plugs and they should be on the center two cylinders. So what is the firing order? 1342?

He said he didn't remove the plug wires from the coils. But, obviously, he had to remove the coils and plug wires to remove the plugs.

S/V40s have marked plug wires so you know where each wire goes.

He swapped the wires between one and two.

The coils are in the right place.

Swap one and two.

[KLowD9x]

Originally Posted by ZVOLV

That was it. Starts up and runs smooth!

Now it throws a 300, 351, and 352 code...

P0300 - misfire, random cyl.

P0351 - Ignition coil (a) no signal (from you trying to start with the coil out).

P0352 - Ignition coild (b) no signal

Clear the codes.

Replace the spark plugs.

Roll it.

[ZVOLV]

Originally Posted by KLowD9x

P0300 - misfire, random cyl.

P0351 - Ignition coil (a) no signal (from you trying to start with the coil out).

P0352 - Ignition coild (b) no signal

Clear the codes.

Replace the spark plugs.

Roll it.

Going for a test drive right now. I erased the codes twice but they come back.