Hello everyone , I have been a member here for a while but my account must have been deleted from non use. I am hoping i can get some help with an issue.

codes showing on my 1999 toyota 4 runner 3.4 automatic 4wd = codes p1300 p0302 p0300 . I was just now able to get the codes , Seems every time i pull into a auto parts store the check engine light would go off and they found nothing. So i started trouble shooting it on my own.

about 3 weeks ago my 4 runner started missing , It runs great for about 10 minutes then after warming up it starts missing. I have also noticed that when i drive it a short distance , park it then start it back up a few minutes later it is missing. Here is what i have done already..

Used water on the exhaust manifold and could tell the #2 cylinder was the one missing.
Replaced Plugs , Wires and Coil packs . It now runs smoother while its not missing but it still misses after driving as mentioned above.

If anyone could help me narrow the issue down i would appreciate it. Im not a mechanic but from what i have read i should probably replace the injector next , I am going to try to get the compresion also but with it running fine while cold i am not sure how accurate it would read. What do you guys and gals think?

 

http://www.myautorepairadvice.com/p0300.html


Recently install el cheapo spark plug wires? Check for a vac leak. At night, look in the eng bay and look for arcing.

 

Thanks for the Reply Zuk , It started missing with the same plugs and plug wires that had been on it for about 2 years. I will check for arcing tonight. Whats the best way to check for vacum leaks , I have read that starting fluid. If thats a good way to do it where do you think would be the best places to test that could cause this issue?

 

If your going to work on this yourself get a simple code reader .

The Factory Service Manual is great as well if only for the diagnostics

You maybe having ECM issues something getting hot and causing problems

 

Hello again everyone. I do not have alot of spare time and just now got around to working on it again. Here is what i have done so far

New Plugs , New Plug wires and Coil Packs
New Fuel Filter
Run 1/2 tank of fuel with sea foam in it
Checked for vacuum leaks and did not find any
Checked compression. All cylinders Read between 170 and 176

After doing all of this i took it back to the garage and had them check codes , Only one code is showing now code 302 , Misfire on #2 cylinder.

What do you all think it could be?
Would the ecm cause on #2 to misfire?
What about the TPS?
# 2 injector?

I am going to try to get a manual for it over the weekend.

 

Thanks everyone . I fixed to problem

 

Ok well just what did it happen to be??

 

Thanks everyone for the help. After clearing all the codes and doing the work listed in my previous message the only error code was the misfire on cylinder #2 . I replaced the injector and she is running great . I am thinking the injector has been performing badly for a while because it seems to run alot better than it has in a long time. Smoother and has alot more power. Thanks again everyone for helping me with this issue.

 

Okay, so I've been working out a similar issue for about a year. (2002 Tacoma 4x4, V6 w/ 280k)

Replaced all the coils and wires, replaced MAF and replaced the entire injector set, figuring it was an injector issue. I'm still getting the same code (302).
Most all of my research goes back to "INJECTOR 2". Why? This is pretty consistent across every forum board. I also read about this cylinder being the one that causes exhaust valves to burn. WTF is up with cylinder 2?

 

If you've swapped or replaced the coils and the plug wires and the injectors and cylinder 2 is still stubbornly refusing to fire, time to start suspecting some mechanical damage.

I'd still first spend a little effort trying to make sure it's not a wiring issue on the #2 injector. It can't be a wiring harness issue on the coil, because you'd have two misfires then. Maybe get one of those little plugin 'noid' diagnostic lights - see if you're getting the proper electrical signals to the injector.

If that seems to be working, time to do a compression test. You can sort of smoke test it by disabling the fuel injection by pulling a fuse (so it won't start), then cranking it over. And pay attention to how much the starter labors over each compression. Just try and sense if there are any unevenness where the starter just sort of sails on by one of the compression strokes. Whir-whir-whir-weee-whir-whir.. Usually by the time a compression leak is bad enough to be setting a CEL, it's going to be pretty obvious.

Or just skip straight to a compression test. And/or a leakdown test. If it's leaking, it's important to know where it's leaking.

 

Good advice, thank you.
I just ordered a compression gauge.