Misfire with no CEL

[Bad Luck]

Crank bolt torqued to 217 ft/lbs?

Just get the banjo bolt with a couple of brass crush washers to attach to a normal fuel pressure gauge. But usually the pump failing is either is a hard start or will die under load, per going up a long/steep climb.

Any change in MPGs?

Yes it is. Mpg’s are down a couple but I’m blaming that on the misfire and engine having to work harder to overcome it

 

[LittleCaesar]

Good luck with the coil replacement. Hopefully that cures the misfire.

 

[T.Tech]

I know this sounds dumb but have you checked the oil level. Have seen someone double fill the oil and caused similar symptoms to what you are experiencing. Doubt it’s your fuel pump, your fuel trims would be in the positive if it was starving for fuel and it would set a lean code if it was so lean that it was misfiring, sounds spark related to me.

 

[Js'00imited4runner]

Sounds like its fuel related. Probably the pickup screen at the bottom of your fuel pump/tank sucking up gunk and it's not flowing freely. (I've got a similar problem going on as you). Flush out your fuel filter and see if you get a bunch of gunk coming out of it. https://www.youtube.com/watch?v=JiA5v9u97OQ
Here's a video of a spot to hook up a fuel pressure gauge on the fuel rail.
Good luck.

 

[The Cold War Kid]

Spend $3 on a PCV valve. Might get lucky.

 

[Mackalicious]

I've been dealing with an intermittent misfire for the past month that has been gradually getting worse and worse. It started out misfiring at lower rpm's and higher load (think highway speeds going up a slight grade). At first I thought it might have been torque converter shudder but as it got worse it would eventually do it in all gears sometimes even just idling. I've been using a 2000 FSM to help diagnose my problems. Misfire is rhythmic which leads me to believe it's 1 cylinder misfiring. No current or pending DTC's.

Helpful info: 2000 4Runner Limited 4WD 3.4 216xxx miles
-Fuel filter replaced w/OEM in March 2019
-Tried different set of known good spark plugs with no change
-injectors changed 15 miles ago with remanufactured injectors from LC Engineering 5VZ (V6) Equalized Fuel Injector Set (99-04) New injectors 13.9 ohms resistance at 80 degrees fahrenheit.
-plugs/wires changed 800 miles ago when valve cover gaskets were done.
-removed plugs and verified clean and properly gapped (new OEM dual electrode)
-Resistance checked spark plug wires (new OEM wires)
-Resistance checked ignition coil boots 1.2 to 1.3 ohms no rips or tears
-Resistance checked coil packs while hot and cold
HOT: #1=1.2 ohms primary/14.7K ohms secondary
#2=1.3 ohms primary/14.31K ohms secondary
#3=1.2 ohms primary/14.34K ohms secondary
COLD: #1=1.1 ohms primary/13k ohms secondary
#2=1.2 ohms primary/12.67K ohms secondary
#3=1.1 ohms primary/12.72K ohms secondary
-Verified voltage at ignition coil packs. All coil packs had 12.17V with battery/source voltage at 12.26V. (Key had been on for a while so I'm not concerned with the lower battery voltage. Vehicle shows 13.8-14.4V while engine running.)
-Resistance checked camshaft position sensor (hot): 1374 ohms
-Resistance checked crankshaft position sensor (hot): 2437 ohms
-Resistance checked MAF: 1354 ohms @ 90 degrees fahrenheit
-Resistance checked TPS: 496 ohms closed and 2673 ohms open.
-Resistance checked ECM to Igniter T9 wiring: 0.4 ohms
-Resistance checked Igniter to Ignition Coil wiring:
T1 to Coil #3=0.2 ohms
T2 to Coil #2=0.3 ohms
T10 to Coil #1=o.3 ohms
-Compression tested 190-210 psi on all cylinders
-No noticeable coolant loss
-No vacuum leaks found. Used Carb cleaner spray method.

Any helpful insights or additional things to check would be greatly appreciated.

Have you tried resetting the DTC's? Once it starts misfiring it likes to keep the cylinders deactivated even if you fixed the issue.

 

[Bad Luck]

Good luck with the coil replacement. Hopefully that cures the misfire.

Thanks! I really hope so too! Fingers crossed.

I know this sounds dumb but have you checked the oil level. Have seen someone double fill the oil and caused similar symptoms to what you are experiencing. Doubt it’s your fuel pump, your fuel trims would be in the positive if it was starving for fuel and it would set a lean code if it was so lean that it was misfiring, sounds spark related to me.

Oil level is at the correct level.

Sounds like its fuel related. Probably the pickup screen at the bottom of your fuel pump/tank sucking up gunk and it's not flowing freely. (I've got a similar problem going on as you). Flush out your fuel filter and see if you get a bunch of gunk coming out of it. https://www.youtube.com/watch?v=JiA5v9u97OQ
Here's a video of a spot to hook up a fuel pressure gauge on the fuel rail.
Good luck.

Fuel filter was replaced in March and the old fuel filter was pretty clean. Thanks for the video. If the ignition coil doesn't fix it I'll check fuel pressure there next.

Spend $3 on a PCV valve. Might get lucky.

Replaced pcv and pcv grommet with OEM when I did valve cover gaskets.

Have you tried resetting the DTC's? Once it starts misfiring it likes to keep the cylinders deactivated even if you fixed the issue.

There are no dtc's current or pending to reset. There are no dtc's at all.

 

[jgue467]

... There are no dtc's at all.

Maybe a bad ECM? :cowboy:

 

[Mackalicious]

There are no dtc's current or pending to reset. There are no dtc's at all.

No pending or history? Try and clear things anyways. Do you have a scantool to show the PIDs for cylinder misfire count? Not sure if the cheap bluetooth ones will show that or if toyota offers the PID.

You want to post up a video so I can hear the misfire along with some engine bay pics/video

 

[Bad Luck]

No pending or history? Try and clear things anyways. Do you have a scantool to show the PIDs for cylinder misfire count? Not sure if the cheap bluetooth ones will show that or if toyota offers the PID.

You want to post up a video so I can hear the misfire along with some engine bay pics/video

There's nothing to clear if there is no pending or current codes. Bluedriver and ultragauge do not show misfire data. Toyota techstream will, but my chinese knock off techstream is having difficulties at the moment. If the ignition coil doesn't fix it tomorrow then I'll post up a video.

 

[T4topher]

Compression was 190-210 on all cylinders and no coolant loss. Timing belt/water pump was done in March around 3k miles ago. No coolant loss.

If you have only done a compression test it might be worth trying to do a leak down test.

 

[Bad Luck]

Replaced ignition coil #1 with Denso 673-1201 ignition coil. Test drove 3 different trips totaling 30 miles with no misfires in a wide variety of driving environments and varying throttle loads and speeds. I'm hoping this is the fix, but if it's not I'll be posting here again.

Thanks everyone that offered their input and ideas on the subject! It's not the first time I've had a bad component that tested within manufacturer's resistance values but didn't operate correctly, but it's the first time it's happened to me with Toyota.

 

[brillo_76]

Glad you got if fixed Badluck..:thumb:

 

[Captsolo]

Set if 6 ignition coils $75 at Amazon

Set if 6 ignition coils $75 at Amazon

https://www.amazon.com/Ignition-200...ition+coil&qid=1570203469&s=automotive&sr=1-5

 

[brillo_76]

Set if 6 ignition coils $75 at Amazon

https://www.amazon.com/Ignition-200...ition+coil&qid=1570203469&s=automotive&sr=1-5

Those are not the coils for a 3rd gen 4 Runner as each the V6 uses 3 coils as each coil drives 2 cylinder. As the description says 2005 -2015 3rd Gens are 1996-2002 ;-)

These are

https://www.amazon.com/Denso-6731201-673-1201-Ignition-Coil/dp/B002Y39NFY

 

[Bad Luck]

Glad you got if fixed Badluck..:thumb:

Me too! I was starting to get really worried!

 

[The Cold War Kid]

Plugs are clean and wires test well below the 25k ohm per FSM

25 K ohm? Methinks not. 10 K ohm. No more.

Still, I think you have a flaky coil.

 

[Bad Luck]

25 K ohm? Methinks not. 10 K ohm. No more.

Still, I think you have a flaky coil.

Toyota Factory Service Manual says "CHECK RESISTANCE OF HIGH−TENSION

TRY ANOTHER IGNITER
Maximum resistance; 25 kΩ per cord"

No misfires since new ignition coil.

2000 FSM: 2000 4Runner FSM - Printable - Google Drive
IG-1 if you want to see it yourself.