canadianjerkey

First off, Hello! I'm Matt and I'm the proud owner of a 2000 Tacoma Prerunner with a 3rz-fe engine!

Ok, maybe proud owner is a bit of a misdirect...

This engine is killin' me! I've been getting hit with codes! Specifically po300 and po302 codes. So I am getting a misfire in cylinder numbah two, easy enough, gas spark or air right?

Well the truck has had this done so far -

Head pulled, valves checked, replaced burned valve, new coil, new plugs (all denso). This was all done professionally by a shop.

But then the light came back.

So now I've taken onto myself to fiddle with it! I've done a reasonable amount on my old 22re and my previous ej25 (subaru). So I figure it's worth a go.

So now -
Plugs checked - All the same, nothing fouled out! (less than 3k old)
Coils checked (indv coil packs) - the #2 coil has been replaced (less than 3k old). All visually fine.
Compression checked - all even, all 190psi (+-4psi).
Fuel filter replaced
Air filter replaced

The engine seems to run fine, pulls fine (I mean, for a little 4-banger), but it has a little bit of a rough idle at times. It just got smogged, and passed with flying colors (CEL stayed off for about 150mi).

I'm thinking about going to the throttle bodies, and the MAF and cleaning them next. Any thoughts?

Let me know if there is anything I might have forgotten to mention? Noobie mistakes being common and all.

Cheers!

rokblok

iTrader: (1)

I'm trying to remember on my 98 3RZ, but I believe there is an idle air control solenoid on the throttle body. Maybe remove and clean and re-install with a new gasket. And make sure the throttle blade is good and clean. Also you may want to be sure to get MAF cleaner and Throttle body cleaner instead of plain carb cleaner....

Mine sometimes does the lower, rough idle, but I haven't gotten any CEL from it. Let us know what you find.

250000_yota

Have you checked the fuel injector? If cleaning doesn't narrow it down, you might try changing the injector on cylinder 2 to another cylinder, and see if the misfire follows.

canadianjerkey

I will definitely swap injectors and see if the code swaps! A quick stethoscope tells me that the injector, at very least, is trying! MAF and TB are on the way too! I'll post pictures if it's something ridiculous, like a snake, stuck in it.

What I had forgotten before: I am assuming that this is the same code it usually throws. Right after I reconnected everything after doing the compression tests, the CEL went away. It came back on after 150mi driving, and adding SI-1 to the fuel tank. At that point the tank was about 3/4 full, and the engines self diagnostics had EVAP as the only incomplete (CA allows for one incomplete to pass Smog). So maybe there is a chance that the fuel additive was mis-timed and triggered the code?

Anybody have any experience with one of these guys?
Might be a neat way to avoid bugging the local shop to do scans.

Thanks for the quick responses guys!

canadianjerkey

Well, went ahead and cleaned the MAF and the throttle body.The idle is improved slightly, but that could be due to resetting the codes causing a slightly higher idle for the time being. Swapping plugs to see if I can move the code. I'm thinking maybe the new coil isn't OEM and therefore prone to failure? Kinda shooting in the dark . Going to smoke the air intake too, see if I can find any leaks...we will see...

canadianjerkey

Ok, code is still reading on cyl2, so it's not the coil pack (4 indv coils per plug 3rz ).

But I do have a new code! P1305 - igniter circuit malfunction to cyl2. So that leaves me to believe there is a short somewhere in the harness, or maybe the ECM? Yeesh.

Anybody have any further insight? Help!

– Matt