#2 Misfire - P0302

J

johnsIslander

New member
Driving my 4Runner home the other night and it started riding rough. I had a CEL on before this of P0171 (I think). Never fixed it. After it to started riding rough, I have P0302 plus P0171. It "shimmies" at idle and power is gone. I've also had the dreaded FLASHING CEL when driving.

I've checks coil packs, sparks, and fuel injectors. Checking the fuel injectors with a supercharger was a lot of fun by the way. All checked out fine, I'm stumped for now. Any ideas?
 
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Have you moved coils around and injectors to see if misfire moves to another cylinder?
 
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maclean216 said:
List your year, milage, and mods. What parts did you actually replace? Are they OEM replacements?
Click to expand...

1997, SR5, V6 - 5VFZE, Supercharger, 270,000 miles

I swapped coil packs and changed spark plugs with no change. I checked the resistance on the #2 fuel injector and it was 11 ohms. I replaced it with a rebuilt injector that I had anyway.

Could it be something as simple as the MAF? I haven't checked it yet.
 
johnsIslander said:
1997, SR5, V6 - 5VFZE, Supercharger, 270,000 miles

I swapped coil packs and changed spark plugs with no change. I checked the resistance on the #2 fuel injector and it was 11 ohms. I replaced it with a rebuilt injector that I had anyway.

Could it be something as simple as the MAF? I haven't checked it yet.
Click to expand...

When I had a misfire code I had to replace the coil packs with new ones. I also put new wires and plugs.
 
If those come up good, I would swap injectors with another cylinder. Known good>>>rebuilt injector out of the box.

What does #2 spark plug LOOK like? (First thing I do on a single cyl miss is eyeball the plug.)
 
TheDurk said:
If those come up good, I would swap injectors with another cylinder. Known good>>>rebuilt injector out of the box.

What does #2 spark plug LOOK like? (First thing I do on a single cyl miss is eyeball the plug.)
Click to expand...

I think it looks fine but then again I don't know what to looking for
 

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johnsIslander said:
I think it looks fine but then again I don't know what to looking for
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1. It's the wrong plug. You want a double element plug. Did you replace with the same plug or get the right ones?
2. It definitely needed to be changed.
3. Not looking like a head gasket issue.
4. Black dry deposits suggest it running rich, so maybe the plug is wrong heat range or maybe you have a sensor issue (MAF, O2).

I'd prefer a better angle on the business end, but that's a start.
 
As Durk said not a HG issue the way that plug is looking. Definitely running rich.

How long have those plugs been in there? How did the plugs look on cyl 4 and 6?
 
johnsIslander said:
1997, SR5, V6 - 5VFZE, Supercharger, 270,000 miles

I swapped coil packs and changed spark plugs with no change. I checked the resistance on the #2 fuel injector and it was 11 ohms. I replaced it with a rebuilt injector that I had anyway.

Could it be something as simple as the MAF? I haven't checked it yet.
Click to expand...

If your coil packs tested good & you changed your spark plugs, I would go ahead and do the rest of the basic tune up stuff if it hasn't been done already. This way you can get caught up on maintenance & troubleshoot at the same time.

1. Spark plug wires if the current ones are old
2. Dual ground spark plugs
3. Clean MAF
4. Clean throttle body & replace the TB gasket
5. PCV valve/hose/grommet
6. Check the the air intake hose for cracks (especially where it attaches to the throttle body)


After I completed the above list a few weeks ago it resolved a few issues I was noticing:
-a faint whistling sound that seemed like it was coming from the engine bay
-occasional tap sound during hard acceleration which was usually noticed on the highway. The best way I can describe the sound is a bolt gently tapping against a skid plate. Sounded like it was coming from the front passenger seat area or passenger side of the engine bay.
-occasional "bucking" sensation which was also usually noticed on the highway
-a very mild delay accelerating from a dead stop (this only happened once & was just as I was pulling into my neighborhood to start the maintenance work).

It never fails to surprise me how a basic tune up can give a little more pep to how a car runs and add a few extra mpg.
 
Following your suggestions: I replaced my spark plugs and all wires with NKG double grounds spark plugs. I also cleaned the MAF and TB.

While I had the plugs out I did a compression test but not sure what to make of it. I've never done this test before so I'm NOT confident with the accuracy.

1 - 195
3- 200
5 - 190

2 - 190
4 - 180
6 - 190

I attached a pic of the old plugs too for any spark plug readers.

And after all that the 4Runner seems to be running better than before but i haven't been on the road yet.
 

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TheDurk said:
1. It's the wrong plug. You want a double element plug. Did you replace with the same plug or get the right ones?
2. It definitely needed to be changed.
3. Not looking like a head gasket issue.
4. Black dry deposits suggest it running rich, so maybe the plug is wrong heat range or maybe you have a sensor issue (MAF, O2).

I'd prefer a better angle on the business end, but that's a start.
Click to expand...

Those are Iridium plugs which are recommended to run with a supercharger because you want a colder plug. I run the Iridium Denso IK22's with great results and no pinging. However, the electrode tips do look worn, hard to say just from looking what the gaps might be.

You can run double-grounded copper plugs with a supercharger but you might get some pinging from it. If there was a double-grounded colder Iridium plug that'd be perfect, but I haven't seen one at a decent price yet. The single ground basically cuts their lifespan in half and can cause the gap to get too big. The second photo resembles how my spark plugs look color-wise, maybe a tad bit lighter though.

Your compression number look good though, you'd notice a significant drop in one of them (cylinder 2) if there was a problem with the valves. I would clean the MAF and make sure everything else looks good fluid wise to see if you find any clues, otherwise it sounds to be your injector (if your coil pack was bad, you'd have two cylinders not firing).
 
They all look a little rich. If the O2 sensors haven't been replaced, do so with Denso ones off Amazon. Shouldn't be too expensive.
 
gamefreakgc said:
Those are Iridium plugs which are recommended to run with a supercharger because you want a colder plug. I run the Iridium Denso IK22's with great results and no pinging. However, the electrode tips do look worn, hard to say just from looking what the gaps might be.

You can run double-grounded copper plugs with a supercharger but you might get some pinging from it. If there was a double-grounded colder Iridium plug that'd be perfect, but I haven't seen one at a decent price yet. The single ground basically cuts their lifespan in half and can cause the gap to get too big. The second photo resembles how my spark plugs look color-wise, maybe a tad bit lighter though.

Your compression number look good though, you'd notice a significant drop in one of them (cylinder 2) if there was a problem with the valves. I would clean the MAF and make sure everything else looks good fluid wise to see if you find any clues, otherwise it sounds to be your injector (if your coil pack was bad, you'd have two cylinders not firing).
Click to expand...

Ok. That didn't sound right so you made me look it up.

Not quite. That's a BKR5EGP, so it's platinum, not iridium, and it's the same heat range #5 as the OEM BKR5EKB-11. Iridiums would have I or IX instead of GP. At least that's what the NGK web site tells me. A colder plug would have a number greater than 5. Absent the S/C, the black deposits would suggest he might need a hotter plug, not colder.

As I know nothing about superchargers, I'll stop there, except to say that platinum is not that big a step up from the nickel plated copper, and probably a step down when you go to single element from double in terms of life. Iridium is a different ball game in performance and cost.

BTW, bad coils frequently fail only on one plug or the other. I know it's not logical, but the detection systems are not perfect. I used to think that way, until life taught me different.

https://www.ngksparkplugs.com/assets/design_symbols_plugs.pdf
 
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gamefreakgc said:
Those are Iridium plugs which are recommended to run with a supercharger because you want a colder plug. I run the Iridium Denso IK22's with great results and no pinging. However, the electrode tips do look worn, hard to say just from looking what the gaps might be.

You can run double-grounded copper plugs with a supercharger but you might get some pinging from it. If there was a double-grounded colder Iridium plug that'd be perfect, but I haven't seen one at a decent price yet. The single ground basically cuts their lifespan in half and can cause the gap to get too big. The second photo resembles how my spark plugs look color-wise, maybe a tad bit lighter though.

Your compression number look good though, you'd notice a significant drop in one of them (cylinder 2) if there was a problem with the valves. I would clean the MAF and make sure everything else looks good fluid wise to see if you find any clues, otherwise it sounds to be your injector (if your coil pack was bad, you'd have two cylinders not firing).
Click to expand...

I didn't realize the spark plugs caused the pinging sound. I'll keep that in mind next tune up. My 4Runner is running strong right now. Also...I've one molded vacuum hoses I'd like to replace to the superchargee. How do I find these parts?
 
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It depends but for the most part yes though don't expect it to start sipping gas like a Corolla.

Just take the vacuum line to a parts store and they should have the right size vacuum line or stop by Fred Anderson on Savannah Hwy.
 
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