Coil packs and problems with coil packs??

burns5150 · Post by **burns5150** » 16 Nov 2011, 18:03

Hey guys, I have related problems on here, but I want to start a new thread to ask about my coil pack problems.
My car is a 2000 S40 Turbo (180,000 + miles). I have had a number of problems and I am trying to work them all down. I think I have a combo of a few going at the same time.
I hade a computer throw codes P0351(Coil A Primary-Secondary Circuit Mal.) and P0300B (Randon Misfire Mult.). ...Other codes are P0341, P0101, and P0335B
What are the number of the cylinders? Does 1-2-3-4 start from the timing gears? If so, My coil 1 and 4 are bad with no fire. They are also connected by a cord.
Two of them (3 and 4) look like coil packs, but (1 and 2) look like regular plug boots , yet both connect to the other 3 and 4??
Can someone give me the school lesson on coil packs and this type placement??
Other things done:
Changed Cat. Converter
Crankshaft Pos. Sensor
Cleaned throttle body
New plugs
Cleaned MAF with MAF cleaner
Checked for vaccum leaks

Post by **jimmy57** » 16 Nov 2011, 21:30

Yes, 1 at t belt end. That engine has wasted spark ignition. The cylinders that are paired (1 and 4, 2 and 3) fire the plugs on both cylinders at the same time. If you pulled cylinder head off and watched, the 1 and 4 pistons would be at the same exact place in their respective bores with 2 and 3 traveling together. Each half crank revolution two pistons come to TDC and one plug drives combustion and the other is on exhaust stroke and the spark does nothing (wasted). The two plug wires are cheaper than two more coils and you save two transistors for the two coils not used. A lot of engines used this arrangement from late 80's through late 90's with a few more having even later. The S40/V40 car came out in 95(not in USA) so it was in the middle of that technology period when it was developed.

burns5150 · Post by **burns5150** » 17 Nov 2011, 05:25

Thanks Jimmy,
That is a pretty interesting set up....I appreciate the info on this engine. I have never seen a set-up like this before(which I am not much of a mechanic anyways). The guy at the parts store said that the car had THREE coils, so that even threw me more in a loop than ever, even after explaining what the set up look like. He said that I need to bring the car in (wow, with two out of four bad coils!!!) I was loss for sure after that!
Glad to know more and more about this car....Well, back to "that guy at the parts store" and tell him he can keep one of those three coils !!