Hi Scotty,

I am having a problem with a random misfire on my 2006 Suzukii Forenza. About 2 weeks ago i was driving down the highway any my car started to misfire really bad out of nowhere. First first thing I checked was to make sure the motor oil wasn't a milky color. Everything is fine there. Then I took apart the timing assembly and had a blown apart idler pulley but the belt was not broke. I replaced the idler and the tensioner and for the heck of if it I put new spark plugs in. When I turned the engine after I repaired the timing it was moving very smooth. So I know none of the valves and rods were bent. I put everything back together then started my car up. Now i was reading a misfire on cylinder 4. I then replaced the plug wires and coil. The misfire then moved to cylinder number 1. The next thing I did was take the fuel injectors out to give them a good cleaning. They were actually not that dirty. Just had very little gunk on them. Well, put all of that back together and now I am getting a P0300 (random misfire). I am at a loss now. I don't think it is a vacuum leak due to the misfire changes cylinders and now it just reading a random misfire. I am at a loss right now. Could a dad cam or crank sensor be causing this? Your thoughts?

Thanks Scotty


No. 1-1

start with a good scan tool to analyze things like cam and crank sensor readings as the engine cranks. BUT, knowing suzukis, first do a wet and dry compression test of all engine cylinders, cause often those engines just blow internally and of course take a pressure reading of the fuel pump and PRAY it's just a shot fuel pump, sometimes it is