All,

Was getting a check engine light for Cylinder # 3 Missfire. Replaced the Rotor Button, Distributor Cap, Wires, and all 5 Spark Plugs. Now getting a Code for Cylinder # 5 missifre and the car is running rough between 50-60 MPH. Running rough at idle aswell but i think that is a seperate issure itself.

After reading some posts today i am going to inspect the plug on cylinder # 5 tonight when i get home. One answer that i am not finding is what should the gap be for my car? (98 Volvo S70 Turbo T5) I am keeping my fingers crossed that it is somthing as easy as a spark plug and not somthing big time wrong with the car.

 

.028 is the gap
Clean the MAF just in case
Any other codes?

 

Also, check the wires to see what date is on the wires. If they are older than 7 years, replace the wires. The date is something like, week/year (29/07). Our S70 had original wires on it so I replaced the plugs, wires and distributer (and cap).

 

Check your Catalyctic converter as well.

 

Alright guys - an update.

Replaced All 5 Sparkplugs, all wires, rotor button, distributor cap. The other night after reading Elco's Post i pulled all the spark plugs out (They were pre gabbed at .45) I regapped them to .28 and hoped for the best.

And boom still getting a Cylinder 5 missfire code! Could it be the Injector?? Is there even a way to test those? or is it just replace and try?

CAT is good, Not glowing red when car is hot, and not making and sort of noice.

Thanks for your help so far guys.

 

One more thing check the # 5 spark plug for cracks,I overtighten one not too long ago and was the cause for my # 2 misfire.

 

There is a chance you have a bad coil, however, the fuel injector could be bad. The easiest way to check an injector IMO is to disconnect the rail, swap the injectors (2 with 5) reinstall the rail and see what happens.

Do you run injector cleaner through the gas sometimes? It really is a GOOD idea to do so every 5,000 miles. Since I run 93 octane, I usually do it twice per year or every 10,000 miles, which ever comes first.

If that doesn't do it and the misfire is still at 5, I would do a compression test.
Compression Test - Volvo S70 GLT, 1998