3rd Gen 4runner not running right

Kramer

Rock Stacker
Joined
Nov 16, 2023
Messages
33
1998 4runner 240,000 miles. 3.4L automatic. I bought it 10000 miles ago and did all the maintenance, timing belt, water pump, PCV, fuel filter, spark plugs, wires, Coils fluids etc.
Ran great for 9000 miles ish
Drove to work 1 Morning and parked it. After work went to go get on the highway and had no power. Just about had to floor it to get over 40. Got off the highway right away and limped it home. Put a fuel pump in it and it seems pretty good but not as it was. Can run over 70 but struggles to maintain speed. Cleaned the mass air flow sensor, pulled all the plugs, photos below.
No codes
First spark plug is bank 2 and they all were similar, second pic is bank one and they all looked just like this
I think bank 2 is running lean
Could not find any Vacuum leaks
Thoughts? Any other info I can supply?
 

Attachments

  • 20240322_152510.jpg
    20240322_152510.jpg
    749.7 KB · Views: 240
  • 20240324_124908.jpg
    20240324_124908.jpg
    1,016.4 KB · Views: 186

On the RX

Rising Sun Member
Joined
Nov 19, 2016
Messages
2,414
Location
Superior
You covered 96.67% of what I would do. Next would be to either run injector cleaner through it or pull the injectors and have them cleaned. Another possibility could be a bad or partially plugged catalytic converter or maybe a caked air filter?
Maybe check to see that the fuel pump is producing enough pressure? I have installed one that went bad after a single tank of gas.
 

SteveH

Hard Core 4+
Joined
Aug 10, 2006
Messages
3,224
Location
Colo Springs
Did you use Denso coils, or parts store cheapies? I realize they should throw a code if bad, but it's always best to stick with OEM ign coils on Toyotas.
 

On the RX

Rising Sun Member
Joined
Nov 19, 2016
Messages
2,414
Location
Superior
Did you use Denso coils, or parts store cheapies? I realize they should throw a code if bad, but it's always best to stick with OEM ign coils on Toyotas.
I learned that through personal expirience! It was missing and it didn't make sense to me why until I replaced the coils with oem. I checked the gap on the plugs a half dozen times before buying new coils...
 

Kramer

Rock Stacker
Joined
Nov 16, 2023
Messages
33
No cheapo parts
I did run seafoam in the tank before this issue occurred. Had half a tank of new fuel when this happened. New wix air filter
 
Back
Top