Po305

[Supra725]

Hey guys,

Lately I been having an misfire.

In the beginning, if I drive to work one smooth drive, the engine runs fine, no issues, no misfire

However if I do stop and go, like starting and going to places. It throws an misfire.

If I let it cool back down, the misfire doesn’t happen.
.
On the other cylinders, it doesn't have that problem.

Where should I go to begin with it? Change out the spark plug or the coil pack?

The rig is sitting at 406k miles and I believe is still on the Oem coil packs from 1999.

 

[T4topher]

Hey guys,

Lately I been having an misfire.

In the beginning, if I drive to work one smooth drive, the engine runs fine, no issues, no misfire

However if I do stop and go, like starting and going to places. It throws an misfire.

If I let it cool back down, the misfire doesn’t happen.
.
On the other cylinders, it doesn't have that problem.

Where should I go to begin with it? Change out the spark plug or the coil pack?

The rig is sitting at 406k miles and I believe is still on the Oem coil packs from 1999.

Could try swapping the coil packs and spark plugs see if the misfire moves. Measure resistance on plug wires..

 

[jkoni426]

Another warm start misfire thread... popular topic today. Mine was a bad fuel injector but rule out the easier stuff first.

 

[Supra725]

Another warm start misfire thread... popular topic today. Mine was a bad fuel injector but rule out the easier stuff first.

Jkoni426,

Was yours having similar symptoms as mine too?

How much was it for you to replace the injector? Did you swap other things out like spark plug or coil pack before that?

Thanks

 

[spartacus]

P0303, Did all of the reguler stuf,f spark plugs,wires, Maf, coils etc In the end replaced injector wth Gb remanufactured injector went bad after a few weeks went with the pricey oem which fixed it.

 

[HiLife]

Worked on a friends P0302. Pulled all the coil pack and inspected the plugs. Dried out the and cleaned with carb cleaner the fuel soaked #2 plug. Put everything back. Still P0302. Swap coil packs between #2 and #4. Got P0302, P0304.
No codes after new plugs and new #2 coil pack.
OP, make sure to address your P302 quickly or risk burning up/clogging your cat.

 

[St Runner]

Give it a basic tuneup before you start anything. New plugs, wires and air filter. Clean the MAF and reset the computer. At that milage I would do a compression check next. Then you can start narrowing down the problem

 

[jkoni426]

Jkoni426,

Was yours having similar symptoms as mine too?

How much was it for you to replace the injector? Did you swap other things out like spark plug or coil pack before that?

Thanks

Same symptoms as yours. I could make a single trip anywhere no problems but if I made a stop along the way and restarted warm a few minutes later it would misfire (P0303). My plugs were somewhat new and I already tried swapping coils and did a compression check etc, so I tried plug wires since they were the originals even though they still ohmed out as good. When that didn't fix it and after reading other threads online about the same thing, I knew it was the injector.

P0303, Did all of the reguler stuf,f spark plugs,wires, Maf, coils etc In the end replaced injector wth Gb remanufactured injector went bad after a few weeks went with the pricey oem which fixed it.

I got 6 GB remanned injectors from rockauto also but mine have been fine for the past year or so thankfully. I swapped them out myself for just under $200.

 

[gamefreakgc]

Same symptoms as yours. I could make a single trip anywhere no problems but if I made a stop along the way and restarted warm a few minutes later it would misfire (P0303). My plugs were somewhat new and I already tried swapping coils and did a compression check etc, so I tried plug wires since they were the originals even though they still ohmed out as good. When that didn't fix it and after reading other threads online about the same thing, I knew it was the injector.



I got 6 GB remanned injectors from rockauto also but mine have been fine for the past year or so thankfully. I swapped them out myself for just under $200.

Funny, mine has new coils, plugs, and injectors and I get a very slight miss when I start and drive it warm. Just a slight stumble when idling at a stoplight enough to notice but not enough to throw a code. I always thought it was just my 4Runner that did this but looks like it's more common than I thought. The engine will sometimes run very lean idling when this happens, as lean at 17:1 AFR. After about 5 minutes of driving it goes away and goes back to normal and all power is back.

 

[jkoni426]

Funny, mine has new coils, plugs, and injectors and I get a very slight miss when I start and drive it warm. Just a slight stumble when idling at a stoplight enough to notice but not enough to throw a code. I always thought it was just my 4Runner that did this but looks like it's more common than I thought. The engine will sometimes run very lean idling when this happens, as lean at 17:1 AFR. After about 5 minutes of driving it goes away and goes back to normal and all power is back.

Are the injectors brand new oem? I took a chance with the remans but my thoughts are the circuitry or whatever is fine when cold but expands and/or breaks down when hot, breaking the circuit inside the injector and causing a misfire. Mine wouldn't throw a code every time, would just idle real rough shaking the whole truck. I did get a flashing CEL once going up a hill. Mine would sometimes feel like it kicks back in and be fine as well. Gotta be an intermittent bad connection inside old injectors.

 

[gamefreakgc]

Are the injectors brand new oem? I took a chance with the remans but my thoughts are the circuitry or whatever is fine when cold but expands and/or breaks down when hot, breaking the circuit inside the injector and causing a misfire. Mine wouldn't throw a code every time, would just idle real rough shaking the whole truck. I did get a flashing CEL once going up a hill. Mine would sometimes feel like it kicks back in and be fine as well. Gotta be an intermittent bad connection inside old injectors.

They are also re-manufactured. That could be the cause but I'm not sure. Could make sense when the engine sits, since the injectors are cooled by the fuel and when the fuel stops moving it warms up in the engine bay. Get some cold fuel flowing and the injectors are back to normal? Could be plausible.

 

[itskohler]

I get an intermittent stumble on mine, and just like you its not enough to throw a code. Mine stays as the RPMs go up though and it feels like a rumble ever 1 to 2 seconds depending on RPM. I'm really hoping its not a bearing in the engine and its just something to do with the injectors.

 

[Supra725]

well, I tried with new plugs, wires and even an coil pack. im still having issues.

now im going to swap out the injector as that's the last thing there is to be done. the only cylinder is 5 and nothing else.

what do you guys recommend for the injectors? my mechanic quoted me $810 for oem injectors out the door. I'm going to have my friend help me and save some $$$.

is there alternate fuel injectors that performs as well as oem at a decent price? go for remanufacture? Lce injectors? what else do you I need for the parts?

thanks

 

[spartacus]

well, I tried with new plugs, wires and even an coil pack. im still having issues.

now im going to swap out the injector as that's the last thing there is to be done. the only cylinder is 5 and nothing else.

what do you guys recommend for the injectors? my mechanic quoted me $810 for oem injectors out the door. I'm going to have my friend help me and save some $$$.

is there alternate fuel injectors that performs as well as oem at a decent price? go for remanufacture? Lce injectors? what else do you I need for the parts?

thanks

Just replace the #5. I replaced #3 with oem when I had a misfire.
Replacing injector is fairly simple.
This might help too.
fuel injector replacement
if you have time you can take them out and send em to Home

 

[Bad Luck]

I recommend these guys for fuel injectors: Part Finder – MotorWest Performance

 

[3bears]

interesting, I have used motorwest in the past and had no problems. I have used other places with bmw and volvo and did have issues.. but the place listed by spartacus ( above) says they do cold and hot testing. Had not seen or heard of that before. Says they also include pictures of the injectors during the tests. Price is compatible with motorwest. About to send out some injectors to get 'rebuilt" so now im in a delemia and dont want to gamble. Hmmmm ? Yet now motorwest web site says that high mile brown units can fail elctronically even after rebuild and they then offer a rebuilt Denso with a life time warranty, not sure I understand, isnt that an old uint that is "rebuilt" ?
And it is not so simple with these engines to just say...oh thats not it, ill just pull it all apart again and try another brand/company. You have plenum gaskets, crush washers, o rings and time . well of course you can skip half of that, then chase other leaks later. I dont have time to repeat over and over. I have also played the game of "new OEM" on many import cars...joke most of the time.

 

[Bad Luck]

interesting, I have used motorwest in the past and had no problems. I have used other places with bmw and volvo and did have issues.. but the place listed by spartacus ( above) says they do cold and hot testing. Had not seen or heard of that before. Says they also include pictures of the injectors during the tests. Price is compatible with motorwest. About to send out some injectors to get 'rebuilt" so now im in a delemia and dont want to gamble. Hmmmm ? Yet now motorwest web site says that high mile brown units can fail elctronically even after rebuild and they then offer a rebuilt Denso with a life time warranty, not sure I understand, isnt that an old uint that is "rebuilt" ?
And it is not so simple with these engines to just say...oh thats not it, ill just pull it all apart again and try another brand/company. You have plenum gaskets, crush washers, o rings and time . well of course you can skip half of that, then chase other leaks later. I dont have time to repeat over and over. I have also played the game of "new OEM" on many import cars...joke most of the time.

They recommend using these injectors Denso Fuel Injector Upgrade Set for 3.4L V6 4Runner Tacoma and Tundra – HP831 – MotorWest Performance instead of the brown top injectors that are prone to failure even after being rebuilt.

 

[Supra725]

They recommend using these injectors Denso Fuel Injector Upgrade Set for 3.4L V6 4Runner Tacoma and Tundra – HP831 – MotorWest Performance instead of the brown top injectors that are prone to failure even after being rebuilt.

Badluck,

how are these holding up? go with these over the new ones? I want to new ones but @ $100 + an piece, it adds up.

 

[Supra725]

Just replace the #5. I replaced #3 with oem when I had a misfire.
Replacing injector is fairly simple.
This might help too.
fuel injector replacement
if you have time you can take them out and send em to Home

spartacus, after replacing it. how is yours holding up? any more misfire issues?

 

[gamefreakgc]

I bought mine from here: Denso Fuel Injectors, 1999-2002 Toyota 4Runner, 2000-2004 Tundra, 1999-2004 Tacoma 3.4L. That's a re-conditioned OEM injector. I have a full set from them and they are reliable.