2000 Toyota 4runner SR5 4x4 w/ 3.4L
I've got a mean gremlin that i've been chasing under the hood for a month or so. wondering if anyone who enjoys diagnosing someone else's problems for free wanted to chime in.
Timing belt & WP replaced 12K miles ago. Heads replaced 6K miles ago after a gasket leak. Was running good since. Going up a slight grade on interstate (70mph) when the intake/exhaust note suddenly changed and there was a noticeable lose of power.
Check engine light comes on and off during driving, but condition stays the same.
Below 2,500 RPM it is very sluggish. Once to 3K it picks up power but I think it is just getting back into its power band.
I’ve unplugged the battery several times to reset the computer and the codes continually come back, “cylinder 1 misfire” & “random misfire” each time.
Ran several cans of injector cleaner through it and also replaced the fuel filter. No change.
I changed cylinder 1 spark plug and also the coil pack. No change.
I replaced the cylinder 1 injector. (really thought this was the culprit after reading other posts on simmilar problems)No change.
The passenger side fuel rail pipe was free of obstructions.
Sprayed brake cleaner around most vacuum lines and intake and didn’t notice any changes in idle.
Hooked a vacuum gauge onto an intake port and at idle had a varying reading of 17 to 16 psi that would drop to 15 when the engine stumbled hard.
Piston is not steam cleaned like they were when the head gaskets went out.
I was out of ideas so i took it to the mechanic that did the head job. he checked for signal to the coil pack
swapped coils & plugs around
checked for signal to the injector
ran compression check on it- 25 psi lower than #3 & 5. wasn't sure of the cause, but didn't think that this was bad enough to cause a miss.
ran a leak down test on the cylinder- no leaks
he has not done the following yet:
checked fuel pressure
checked for proper operation of the cam and crank position sensors
but is running out of ideas himself.
any thoughts or ideas on my problem?
Thanks,
I've got a mean gremlin that i've been chasing under the hood for a month or so. wondering if anyone who enjoys diagnosing someone else's problems for free wanted to chime in.
Timing belt & WP replaced 12K miles ago. Heads replaced 6K miles ago after a gasket leak. Was running good since. Going up a slight grade on interstate (70mph) when the intake/exhaust note suddenly changed and there was a noticeable lose of power.
Check engine light comes on and off during driving, but condition stays the same.
Below 2,500 RPM it is very sluggish. Once to 3K it picks up power but I think it is just getting back into its power band.
I’ve unplugged the battery several times to reset the computer and the codes continually come back, “cylinder 1 misfire” & “random misfire” each time.
Ran several cans of injector cleaner through it and also replaced the fuel filter. No change.
I changed cylinder 1 spark plug and also the coil pack. No change.
I replaced the cylinder 1 injector. (really thought this was the culprit after reading other posts on simmilar problems)No change.
The passenger side fuel rail pipe was free of obstructions.
Sprayed brake cleaner around most vacuum lines and intake and didn’t notice any changes in idle.
Hooked a vacuum gauge onto an intake port and at idle had a varying reading of 17 to 16 psi that would drop to 15 when the engine stumbled hard.
Piston is not steam cleaned like they were when the head gaskets went out.
I was out of ideas so i took it to the mechanic that did the head job. he checked for signal to the coil pack
swapped coils & plugs around
checked for signal to the injector
ran compression check on it- 25 psi lower than #3 & 5. wasn't sure of the cause, but didn't think that this was bad enough to cause a miss.
ran a leak down test on the cylinder- no leaks
he has not done the following yet:
checked fuel pressure
checked for proper operation of the cam and crank position sensors
but is running out of ideas himself.
any thoughts or ideas on my problem?
Thanks,
