1989 Toyota 4Runner 6 cyl Four Wheel Drive 100k miles
vehicle starts and runs perfectly. Or it doesn't. Problem been going on for couple of weeks. 3.4L V6
Symptoms same now as when it started. These problem determination steps and possible solutions have been implemented:
By my mechanic, who returned the vehicle thinking it was fixed because it was running perfectly.
Cleaned battery terminals
replaced fuel filter
tested fuel pump pressure. It's OK
replaced spark plugs (driver side bank wet with fuel, other side not)
replaced oxygen sensor
I picked up vehicle, it started perfectly and ran about 60 miles. Stopped for night, didn't start next morning.
Next day I jumped it and it started up, ran rough for about a minute then smoothed out perfectly.
I replaced battery, it ran OK for another 60ish miles then it wouldn't start next morning. I replaced starter.
Still did not start. Starter clearly engages engine, fan and pulley rotate. Sound is not "normal". Sounds like there is no compression.
Took it back to mechanic on flatbed trailer. It would not start for him, same sound/symptoms. He replaced mass air flow sensor, rechecked timing belt and marked it to see if it was slipping. Not slipping
Compression tested OK. Still did not start. Left it overnight.
Started next morning but ran extremely rough for about 2 minutes, then smoothed out instantly. Shut it off and started it again. Very smooth, ran fine.
Mechanic does not believe that the real problem has been fixed and that it could fail again at any time. He has exhausted his problem determination capabilities and given up on the vehicle. Note. Have used him for over 15 years, he's honest, didn't charge me anything for his diagnostic efforts.
Left overnight it started again. Have driven it and started it for couple of days. Running fine and strong at present but am convinced it will die again.
Summary. Numerous reasonable "fixes" have had no affect on the symptoms although they were reasonable to do.
I suspect an electrical problem. What would cause these symptoms, given the analysis and fixes to date?
have the same problem?
Saturday, May 8th, 2010 AT 8:20 PM