FastOlds
02-08-2009, 04:35 AM
Hello all- I have a 98 4runner with a 2.7 4 cylinder engine. It has 173k miles on it, and was running great up until a few days ago. I get an intermittent misfire that started only at 70 + miles per hour. Now it misfires intermittently during all speeds, from 25 miles per hour and above. Idles perfectly. When it misfires, it will sometimes throw a flashing check engine light. The problem is, even with a pretty sophisticated scan tool on it, it won't throw a code.
The plugs all look good, i took them out and checked. they all have even, consistent burn patterns. The wires were original, and showed some signs of arching. I replaced them with OEM wires. They didn't fix the problem.
This thing is so intermittent, i drove it almost 200 miles in between occurances. But when it acts up, it seems to do it in bunches. It seems to really happen on acceleration but seemed to do it at steady highway driving.
My thoughts are either a coil or injector starting to fail. If i could get a misfire code, i would swap the coils around and see if it goes to a different cylinder. I haven't ohmed out the injectors yet, but i honestly doubt that it will show anything abnormal.
The funny thing is, i saw a couple of threads on this forum relating to the same problem, but all of the ones i saw offered no solution, the orginal thread starters never came back to fill us in on what actually fixed their problem.
So I'm asking other 2.7 engine owners to help me with my 4runner. This is honestly the first driveability concern this truck has had in over 115k miles (as long as i've owned it!) and it has me stumped. I have access to Alldata and whatnot, but it doesn't appear to be helping me.
Thanks!
Adam Friday
98 4Runner 2.7 4cyl, Auto, LineX'd Bumpers
The plugs all look good, i took them out and checked. they all have even, consistent burn patterns. The wires were original, and showed some signs of arching. I replaced them with OEM wires. They didn't fix the problem.
This thing is so intermittent, i drove it almost 200 miles in between occurances. But when it acts up, it seems to do it in bunches. It seems to really happen on acceleration but seemed to do it at steady highway driving.
My thoughts are either a coil or injector starting to fail. If i could get a misfire code, i would swap the coils around and see if it goes to a different cylinder. I haven't ohmed out the injectors yet, but i honestly doubt that it will show anything abnormal.
The funny thing is, i saw a couple of threads on this forum relating to the same problem, but all of the ones i saw offered no solution, the orginal thread starters never came back to fill us in on what actually fixed their problem.
So I'm asking other 2.7 engine owners to help me with my 4runner. This is honestly the first driveability concern this truck has had in over 115k miles (as long as i've owned it!) and it has me stumped. I have access to Alldata and whatnot, but it doesn't appear to be helping me.
Thanks!
Adam Friday
98 4Runner 2.7 4cyl, Auto, LineX'd Bumpers