Toyota 4runner 3.4

[Duckgtr]

Im pretty much at a loss. Maybe someone else can give me some ideas.
1997 Toyota 4runner 3.4L V6
The code for the CEL Is misfire in cylinder 6.
I have replaced all 6 injectors, all 6 spark plugs, all 3 coil packs, fuel filter, spark plug wires.
Still runs like crap and still misfires. Please feel free to give any suggestions. 

[swanny]

Jump on T4R.org, lots of guys over there that can probably help you diagnose

[Buckmark]

check compression

[Fl0und3rz]

Does it have a timing belt?  My 1990 3.0 slipped a belt and ran like crap, but no codes available.

[Duckgtr]

check compression

compression is good
1-140
2-150
3-140
4-135
5-140
6-145

Does it have a timing belt?  My 1990 3.0 slipped a belt and ran like crap, but no codes available.

I figure if it was timing belt it would throw off the whole thing. Ill have to check the timing when I get home tonight.

[Buckmark]

Is it consistently cylinder #6 and no others? If so then leak down test that cylinder, inspect for coolant contamination or other issues only on that cylinder. If it is random cylinders then based on what you have done with no change then possible a fuel issue, too little or too much fuel pressure?

[gaddy]

Valve adjustment a possibility ?

[Duckgtr]

Is it consistently cylinder #6 and no others? If so then leak down test that cylinder, inspect for coolant contamination or other issues only on that cylinder. If it is random cylinders then based on what you have done with no change then possible a fuel issue, too little or too much fuel pressure?

Always constant with #6. Ive moved coil packs, spark plugs and injectors. Ill do a leak down test as well tonight

[Buckmark]

If it is that cylinder only and no change with coils, plugs, injectors etc then you have either a mechanical problem or a contamination problem with that cylinder.
Things to check/look for/possible causes
1) valve that is not sealing well, may not show up with a compression test but may with a leak down test
2) Coolant contamination, very small head gasket leak, cooling system pressure test may show this
3) Intake gasket leak at #6 causing it to go lean, smoke test may show this or scan data of fuel trims or oxygen sensor data compared to opposite side

 

[shadowless_nite]

Do you have a way to read live misfire data? If so I would start there and start checking wires. Also what spark plugs are being used, what injectors and what coils?

If you have good compression, i would start checking for coolant loss from headgasket with a cooling system pressure check  or electrical component failing between the harness and ecu. Mice like to crawl all up around the intake and chew harnesses, also the protective plastic on the wiring harness and wire insulator gets pretty brittle overy the valve covers. Check for broken or poor connections. Live feed will let you move stuff around and detect changes. Toyotas are my day job. Let me know how I can help. Rarely ever is a toyota misfire difficult to chase with obd2 and all the parts you've thrown at it.

[BigGoonTuna]

i know, different engines, but the 2.7 in my old tacoma started running rough, with those misfire codes.  turned out it had 2 exhaust valves fried to a crisp.  leakdown test would tell you if it's a valve issue.