So I have been experiencing a cylinder 5 misfire with check engine light coming up sometimes when I accelerate hard. It has happened three times now, the first time the code read "cylinder 3 misfire" but last two times have been cyl 5. I have replaced all of my spark plugs and wires thinking that would do it but still having the misfire and code coming back up when I drive hard. My guess is that my ignition coil has gone bad so I am considering the MSD ignition coil upgrade and Bosch distributor cap and rotor setup. Is it worthwhile going for the MSD ignition over the OEM setup? I dont have any modifications done yet so would it even make a difference? Feedback is appreciated.

 

I recently replaced my plug wires, cap/rotor & coil. All parts were Bosch, but not MSD. 2.3HPT 1998 C70. runs great!

 

You probably won't notice any more power if you only upgrade the ignition to MSD. I would take the cap off and inspect it to see if the contacts inside look worn, or if the cap is cracked anywhere. How many miles are on the car? Is it the original cap/rotor and coil?

 

Mileage is 102k. How easily does the rotor cap come off? Looks to be original and on there pretty good. I may go for the MSD ignition coil as it is pretty much the same price. I've gotten the misfire cyl 5 code three times now when I drive at WOT which leads me to believe the issue is isolated to a faulty point on the rotor.

 

Mine was all origina cap/rotor/coil/wires/plugs. I tapped the cap all around with a screwdriver handle after loosening fasteners, popped off. 14yrs, 36k miles when changed in Jan 2012. 30 min. change everything.

 

I have changed everything but the ignition coil at this point. With new spark plugs, wires, ignition rotor and cap the cyl 5 misfire still comes up when I drive at WOT. I will order a new ignition coil and hope that fixes the problem. When I removed the ignition cap, I found a plastic half sphere "bowl" with a hole in the middle that was sitting between the ignition rotor and cap. The new Bosch rotor and cap kit that I bought did not come with this piece. Is it required? I would rather not have it in there if it is not needed, but it probably serves a purpose right?

 

My new rotor & cap didn't vome with that oiece & my original rotor/cap didn't have it. Pic?

 

I will pull it out and take a pic when my new coil arrives. I thought it was strange. It wasnt connected to either part, just kind of resting on the ignition rotor. Its like a plastic bowl with a hole in the middle. It was laying on its side against the rotor, held in place by the cap.

 

Replacing my ignition coil fixed the check engine light problem. Still a slight choke once in a while.. Im going to try a fuel induction cleaning and fuel filter replacement next. I will take out that plastic bowl part tomorrow and see if it makes a difference/improvement.

 

Try cleaning out the throttle body before you do a fuel cleaning. It's easy and cheap, you can do it yourself, and it is very often related to slow response from the gas pedal.

 

Anybody think that misfiring can be caused by not using OEM Volvo spark plugs? Ive been putting up with random misfires in my C70 for about a year. Ive done just about everything to get rid of it but still persists. I am thinking that it may be simply because I did not use OEM spark plugs when I started replacing ignition parts... I used a set of high performance plugs that don't require gapping.

 

Did you inspect the cap & rotor? Replace the coil? Plug wires?

 

Yes. Replaced rotor cap and coil with new Bosch parts. Replaced spark plugs and wires. Replaced fuel filter. Used numerous BG 44k and MOA additives. Cleaned the MAF. Replaced trans fluid. Car has new PCV system as of 7k miles ago. I don't get any CEL codes after replacing the coil and cap but still sporadic misfires every once in a while. I guess ill pick up a set of OEM plugs to see since they are recommended over the rest.

 

Good idea. I tried Bosch Platinum plugs in my 02 F150. Didn't run right. Installed Autolights. Runs real good. Wasted my money!