I've been fighting a rough running condition on the 4Runner for a few months now. As Onur will testify I've spent a lot of time and coin at AmToy chasing this gremlin. As I've replaced parts the issues seem to get less, but are still there.
The truck now starts fine. At around 150° the truck starts to stumble. It was very bad before the part replacements, but still exists. If I let the truck sit for 20 minutes or so the truck will hardly run until I put some throttle and a little time into it. My air/fuel meter shows a lean condition under load.
To date:
Replaced cold start injector
Replace cold start time switch
Replace fuel press regulator
Replace fuel filter
Replace TPS (code)
Replace Ox sensor (code)
Tried a different ECU
Tried a different AFM
Tried different plug wires
After talking with Evan last night I decided to rule out head gasket. So this morning I ran a compression test.
No1: 180
No2: 195
No3: 170
No4: 180
Not bad for an engine with 120K+ miles on it. I think I can rule out head gasket.
What was not good was the condition of the No4 plug. It was melted. I'm suspecting a lean condition, which I have been suspecting all along. Now, why? I'm thinking about replacing intake gaskets.
The truck now starts fine. At around 150° the truck starts to stumble. It was very bad before the part replacements, but still exists. If I let the truck sit for 20 minutes or so the truck will hardly run until I put some throttle and a little time into it. My air/fuel meter shows a lean condition under load.
To date:
Replaced cold start injector
Replace cold start time switch
Replace fuel press regulator
Replace fuel filter
Replace TPS (code)
Replace Ox sensor (code)
Tried a different ECU
Tried a different AFM
Tried different plug wires
After talking with Evan last night I decided to rule out head gasket. So this morning I ran a compression test.
No1: 180
No2: 195
No3: 170
No4: 180
Not bad for an engine with 120K+ miles on it. I think I can rule out head gasket.
What was not good was the condition of the No4 plug. It was melted. I'm suspecting a lean condition, which I have been suspecting all along. Now, why? I'm thinking about replacing intake gaskets.
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