97 Tacoma misfire

Hello I am helping a friend out with his 97 Tacoma 4cyl. He noticed on a recent trip that it started to misfire at high speeds, had a lopey idle, and was a little underpowered. Also the check engine light started coming on. I pulled a plug wire and noticed he had a orange/yellowish spark (weak), across all cylinders. Local auto parts place read the CEL code and read that there was a misfire on cyl 2.

I had a Dodge Dakota once with the same problem, after replacing all the sensors I threw in a used ECU and it ran just fine. Is this what we need to do for this truck? I noted there are 2 coils (this is my first time working on a tacoma) and the fact that there is weak spark from both of them indicates to me that it is probably not a coil problem. Are there any sensors that would cause this? Common faulty wiring connections?

Many thanks for any insight.

 

I have a 96 Tacoma 3.4 l, 5 speed manual, 4x4r. and started getting a random cyl 3 misfire a couple weeks ago. Found the boot under the coil pack was burned. Replace it (less than a year old) and problem went away for about a week. Was planning to swap coils around if it came back to see if problem moved.

Then on a trip out of town this week, got flashing CEL and checked and now getting cyl 2 misfire climbing hills at highway speed. Plugs and wires are less than a year old.

I have been doing some reading here and plan to clean MAF sensor this weekend and check injectors. May replace plugs and wires.

What is best plugs and wires to use?
What about O2 sensor brands ( I need to replace upstream as I get code on it)?

Thanks.

 

woah!! A whole new ECU? Like 98tacoma27 said, start with plugs and wires, then work to the coil packs if that doesn't help.

But 99% of misfires are caused by a plug and wire problem.

Nice threadjack

OEM plugs and wires are the best choice.

Always use OEM plugs (denso or NGK)

I have used Napa premium wires with good result. They are made in the USA and seem to be quite nice.

As for O2 sensors use OEM (denso). Aftermarket O2 sensors are junk and dont jive with our trucks. try rockauto.com for denso sensors. The dealership will rape you for O2 sensors.

 

Sorry for the threadjack, but I was hoping this thread could lead to my issue and did not want to start another similar thread....

All the FLAPS here want to give me a single ground electrode as this is all they show in their system - NGK BKR5EGP, which has single ground electrode. From NGK website, the Standard and Laser Platimunm er dual ground electrodes. Which one would be best? (if I can find it in this one-horse sized town).


StandardBKR5EKB-11 #

3967

.044​

V-PowerBKR5E-11

6953

.044​

G-PowerBKR5EGP

7090

.044​

Laser PlatinumBKR5EKPB-11 *

4302

.044​

Iridium IXBKR5EIX-11

5464

.044​