Bad Coil Pack???

[ihrunner]

I just bought a used '98 4Runner, Limited, 92,000 miles.

Driving a few days later I got a blinking CEL, then later on it became a steady light, with the occasional period of more blinking

I looked around here and yotatech for suggestions/similiar problems and:


I bought a scan tool and the codes (2 sets of the below) are

P0300
P0303
P0306

I've cleared the codes and they do come back, always the same ones.....


I did clean the MAF, and ran a can of injector cleaner/full tank of gas but the codes keep a'coming... (it does take about 10-minutes for the codes to start popping up)

In looking at a Haynes manual, it shows that the same coil fires Cylinders 3/6 so I'm wondering do I need to replace all the coils if it is bad (i.e. better to do as a complete set????) I 'm not at all familiar with coils.... :bash:

I haven't tested the coil but I'm hoping to do that tonight after work (switching coils and checking the resistance also)

I'll also look/check the ignition wire from that coil (switch it to another set of cylinders???) tonight

What about used coils (junkyard) versus new?? Maybe get a complete set form a junkyard and hope for 1 good one?

Any other ideas if the coil and wires are ok??

Thanks in Advance, and wish me luck!

IHrunner

 

[Her4Runner]

Had this problem awhile back on our 2000... In add. to the CELs (same as yours), truck was chugging intermittently. Almost sure it was ignition. Checked plugs, ohmed spark plug cables, swapped coils, cleaned MAF etc., to no avail. (BTW, there is are two resistance tests you can do on the coils to detrmine if they're w/i spec - s/b in your manual.)

Turned out to be a bad injector! Been purring like a kitten every since.

HTH,
Her4Runner

 

[ihrunner]

First Round of checks

hmmmm.

Coil (already been replaced once, different than the original denso's....) good

Wires - good

Plugs - good, replaced anyway

My 'runner does not chug, it runs pretty smooth.....

Gas mileage: 15.5 mixed city/highway, seems to be in line with what I expected.

It takes about 10-15 minutes for the CEL to start blinking.....

I'll be Seafoaming it over the weekend, we'll see:bugeye:

How can I test the ECU?? if the seafoam'ing doesn't change anything maybe I'll run to a junkyard and rip out an used ecu (I think I saw a thread on here where it did turn out to be the ECU)

Since I have until mid december to get it figured out, (thats when my temp tag expires) I'm so not too desperate yet, and I dig learning more about the 4Runner


IHrunner

 

[ihrunner]

CEL codes

UPDATE:

I Seafoamed my 4Runner, and I have not seen the CEL light again, I had an emission test done and got a "quickpass", so I guess whatever the problem was is gone, but I don't know for 100% what the problem was , or what fixed it .

Ihrunner

 

[96dcmss]

I would suspect coil fist, since you have codes for shared cylinders. Best way to be sure is to swap the coil with one next to it, clear the codes.....then see if the misfres move to the cylinders you swapped the coil with.

 

[The Godfather]

Hi, I am new to this board and just want to say HI! I have been having a similar problem with me 99 4Runner. I am throwing codes: P0300, P0302, P0305. Cylinder 2 and 5 fire off the same coil. I changed out the coil with the one next to it and the same two cylinders are causing the misfire. HERE IS THE KICKER... ...it only happens above 120KPH (80MPH). I can drive for 2 months at 119 and below but within 1 minute of driving above 120 the light turns on (blinks first and finally will stay on). I changed the plugs and wires. I dumped in injector cleaner and changed the fuel filter.

ANY IDEAS?!?

 

[ihrunner]

Bad News / Good news

My saga continues.......

back in May, my 4runner started throwing the codes again.... (300, 302, 305), and my mileage dropped by 2 mpg. I switched coils around (again), cleaned the coil contacts (one was turning a light blue), checked resistance of the coils, and injectors, new plugs, cleaned MAF, Techron, Etc.....:awais:

And, to add to my enjoyment, I started getting a ticking noise from what I originally thought was a valve. While digging around on my car I also noticed that my muffler was shot, and that I had apparently been driving around without my sway bar connected to my front end. It was, as they say, "a very happy place" that I was in.

I immediately took the Runner to a shop where my neighbor is the manager and had the muffler and tie rods fixed, they indicated to me that the ticking noise was from my timing belt, hmmm, according to the sticker on my engine the belt had been replaced less than 20,000 miles ago at 81,000 miles (I bought it used). Of course I went and searched the 'Net for anything, and what do you know, an incorrectly torqued crankshaft pulley can cause issues.

The next day (today) I took the 4runner to a Yota shop and asked them to install a new timing belt (no waterpump, as the rest of the engine had been maintained according to Spec's as evidenced by new fuel filter, O2 sensor, Toyota anti-freeze, NGK plugs w/antiseize, etc...).

It was indeed a loose crankshaft pulley, the tech said that the timing could have been moving around as much as 15 degrees. I needed a new pulley, woodruff key, and bolt, which along with the timing belt change ran me ~$270.00

It feels so much better, of course time will tell but in case my symptoms match yours it is a possibility to consider as part of the process of elimination.....