97 3rd gen 3.4 P0302 cylinder 2 misfire code

[sea_stork]

I have misfire on cylinder 2, according to the parts store scanner. I may drive it a few miles to town, and then it starts the miss on the way back. I drove it to the parts store with the miss, and it ran fine all the way back? I have changed the fuel filter, and spark plugs. The old plugs looked bad, but still has the miss. Going to change plug wires, and try moving a coil pack to see if the miss moves with it/code changes tomorrow.

It was due for the tune-up, but since it didn't make any difference in the miss, I'm wondering what else I may be looking at, and how to check for it. I've read many of the threads from the top Toyota forums, and have also seen fuel injector and crankshaft pulley timing sensor thingy mentioned? I had the timing belt and water pump changed about 6 months ago.

Am I on the right track? Is there something I'm missing, besides # 2 cylinder? :drum:

 

[LittleCaesar]

It sounds like you are attacking the problem logically by changing out the easiest and cheapest first (wires), then coils, and leaving the hardest/most expensive for last (injector).

Keep us updated.

 

[sea_stork]

Drove to town, it ran great. Probably better than before. Between stops at a couple parts stores that did not have Denso or NGK wires in stock, it missed for about a minute, I stopped by another parts store, had it scanned and in addition to the #2 misfire, it had #5 misfire, and random misfire.

But it ran perfect back home? It has a slightly higher idle, about 100 rpm, than it had before changing plugs. Decided to order the Denso wires online since it was less than the local parts stores. Next week before they get here.

I found out a neighbor has a code scanner, so I won't have to drive to town to get it scanned. :cheers:

 

[sea_stork]

Went out and cranked it up today, and as soon as it started to idle down, I could tell it was missing. Good time to check the injectors with an ear and a long screwdriver. #2 injector was not clicking. Crap........

I did used Chevron fuel system cleaner in the tank before I did anything else. Since it's intermittent, I believe it may be the injector failing electronically rather than mechanically. I'll check the connections first. It just sucks it had to be the side under the plenum. :redbrick:



*edit

So I went back out, and with the long screwdriver I wiggled the harness plug on top of the #2 injector ever so gently. I started it, and it ran perfect. The injector is clicking, and it idles at about 700. It may not have had anything to do with wiggling the plug, as it's intermittent anyway. It may have been from just sitting warm while I was checking youtube vids, and posting here. It's definitely an injector based problem. I'm still thinking electrical not mechanical.

 

[sea_stork]

Let it cool, cranked it up, and missing again. Injector not clicking. Wiggled the plug on it with the long screwdriver and no difference. I'm pretty sure I'm looking at changing the injector. Does anyone know of anything else that would cause the injector to not get an electrical signal? My 4runner has 201K miles

New injector about $70-$80.

6 used injectors and both fuel rails with less than 40K miles, $150.

What route should I go?

 

[PitbullRescuer]

If its 2 and 5 now, it's mostly likely either wire or coil. The coil and wire from 5 feed 2.

 

[PitbullRescuer]

If it is injectors, pull all 6 and send them to WitchHunter for cleaning and rebuilding. $21 per injector.

 

[sea_stork]

Thanks pitbullrecuer, I've got wires on the way and will switch coil packs when they go on to see if a coil pack is going bad. That wouldn't cause the injector not to function though. At 201K are the injectors worth rebuilding versus low mileage ones with regulator rails for about the same $$$ ?

 

[LittleCaesar]

+1 with what Pitbull advised on doing.

Switch the coil first, but if you can't hear the injector, or if pulling the connector to the said injector does nothing to the 4runner's idle while it is idling, then it is most likely an injector.

I'd get a new one and if time/money permits, send the other five to Witchhunter.

 

[sea_stork]

Tomorrow, I'm going to try moving the wiring for the injectors to see if anything may be grounding out, just to rule it out. When I get the spark plug wires and start pulling stuff, I'm going to pull all the new plugs and do a compression check to make sure nothing else is going on with #2 or any others before I take the next step.

I checked out Witchhunter's site. It said clean and pressure test for $22 ea. Not sure what an injector rebuild entails but, no mention of it. I'm still kinda leaning towards the low mileage set, and saving the working 5 to send in to Witchhunter if/when needed.

 

[sea_stork]

Moving the wires didn't work. I started pulling stuff. When I got the lower plenum off, and could access the #2 injector, I did an ohm (resistance) test on the injector. It tested 199 ohms, the others go about 15 ohms. Pretty sure the electrical coil (solenoid) in the #2 injector is bad.

 

[LittleCaesar]

It sounds like you have the plan, just need to put it into motion.

Via a friend of mine, the rebuilt Witchhunter injector cost him 1/3 of what a new OEM one would have. It is working fine in his Buick GN three years later.

 

[sea_stork]

Thanks, I'm trying...

I keep hearing rebuilt, but when I checked the site it only described that they clean and pressure test. Probably new O rings and a spray head filter too, but not obviously noted. I don't doubt that would last, as long as the electrical part in the injector doesn't fail, and the fuel system is kept clean. If one of my injectors failed electrically, than another may follow, even if it's clean. Taking the plenum off is a bit of a pain, or I would just pop another injector in #2 and keep on truckin'. I'm replacing them all while I'm under there.

How many miles on the GN when the injector went south, and how many since repairing?

 

[LittleCaesar]

SS,

I will email him and ask (he lives in a different state).

For some reason the nozzle openings for the injectors on the Grand National are a weird size for pulse rate or some other stupid GM reasoning. I am 80% sure Witchhunter rebuilt it for him (they may not now) but let me double check before sticking my foot any further in my mouth.

Just don't get any injectors off Fleabay.

 

[sea_stork]

Compression checks within a pound or 2, one way or the other, of 185 on each cylinder. So far so good.

 

[sea_stork]

Not much help around here, luckily I figured it out by myself.

For anyone who may be experiencing a misfire. Check the injector with a long screwdriver so you can listen to it, before playing parts swapper. If you have a dead injector, and you don't know the complete history of the truck OR you use cheap gas blended with alcohol, the alcohol can corrode the electrical coil on the injector causing them to fail electrically. The coil {soleniod} in the injector is cooled by the fuel. Sending them off to be cleaned does not fix this coil corrosion damage.

I replaced all the injectors, something I've never done. It took about three hours going slow and careful, and I was surprised how easy it turned out to be since it was a bit intimidating. It runs perfect now.

 

[robb1887]

Sucks that it was injectors... those jokers are pricey. I had a similar issue and lucked out that it was just the cables. Before going through the process of buying new parts you can always swap the wires and coilpacks around (they are a little tight but will reach) to see if the misfire moves before looking at the injectors.

I.E. you have misfire on cyl 2.

Swap wire from 5-2 and 1-4
Swap coil from 5 and 3.

If the misfire moves to the 4th cylinder the wire is bad,
If the misfire moves to the 6th cylinder the coil is bad,
If the misfire doesnt move at all... check spark plugs and injectors

 

[sea_stork]

Yeah. I did those on page one, but thanks for reiterating.

 

[LittleCaesar]

Good to hear that the problem is fixed. While I have never had to replace an injector on the 4runner, I have on other vehicles. It is never a fun job.

It is true that once an injector dies, no cleaning job will bring it back to life. Only a replacement or rebuild will get the job done. Using Witchhunter or other cleaning companies only aides in working injectors to help their performance and extend their life.

 

[JustBadLuck]

P0302 - Still trying

I had a very bad sputter in my 1996 4Runner. The diagnostic did not show any codes and the Check Engine light wasn't on.

After reading about 4Runner owners with similar problems, I started throwing parts on it.

I replaced all 3 Coils, all Spark Plugs and all Wires. I also replaced all 6 fuel injectors and both O2 sensors. I also added 44K to the tank twice. I checked the MAF and it looks clean.

After all of that (with no change), my Check Engine light decided to come on and I got a code of P0302.

So, I replaced the Coil on cylinder 2 again...still nothing.

Any suggestions?