check your coils resistance.

 

If your coil is already weak and you didn't gap your plugs properly, you probably aren't getting sufficient spark. When you buys plugs they usually aren't pre-gapped. Even when they are they usually aren't done correctly.

 

OK guys, how do I check the coils? Any instructions? Pictures? Pop-up book? Also, yes, I'm a 'tard and didn't properly check the plugs for proper gap. I figured they were pre-gapped and just popped them in as such. Live and learn I guess.

 

The only plugs I don't have to gap out of the box are multi-tip ones like the platinum 4's. I'm not sure of the readings for a normal coil output, but you can test it with a good voltmeter. If you replace them, see if you can't find a performance one. I changed out the coil on my f-150 with an msd one that was twice as strong as stock so I could upgrade the rest of my ignition system.

 

The low-tech way to test coil output is to pull a plug and see what color the spark is. If it's not blue it's probably weak.

 

Bubble, you're saying I can take the coil out, remove the plug, and attach the plug to the end of the coil like its usually if installed into the engine and just crank the engine to check the spark? Will it hurt anything to have the coil connected to the plug but not installed in the cylinder?

 

NO NO NO, you don't remove the coil. You only remove the spark plug, leave the spark plug wire attached and turn it over. It won't hurt anything, just don't touch it. You can also just remove the wire from the spark plug end and hold a screwdriver close to the end and watch the spark jump and check for color that way. But if your screwdriver isn't rubber handled it's going to shock you. It won't kill you or anything, but it will scare you lol.

 

i think 1mz-fe coils were on a recall list of some kind or TSB was issued for them until production date of 2000 something IIRC.

try searching the TSB listing for gen4, maybe you find something about coils:
http://www.camrystuff.com/manuals/Gen4/Miscellaneous/TSBs.pdf

so, you have no error codes now at all? have you tried driving it locally to see what comes back? usually misfires are pretty quick to come back if they are strong enough, also remember that they may require the 2 trip logic for popping the CEL light up.

 

Misfire is not usually a condition that requires 2 trips to illuminate the MIL. It should flash fairly soon after the misfires start.

 

oh, didn't realize. based on fact that I once saw a pending misfire on my 5s-fe which never becomes a solid error, it happens only in certain situations. thought it's the 2 trip logic causing that.

"If the same malfunction is detected again during the second
drive test, this second detection causes the MIL to light up.(2nd
trip) (However, the IG switch must be turned OFF between the
1st trip and the 2nd trip.)
- Freeze frame data:
Freeze frame data records the engine condition
when a misfire (DTCs P0300 ~ P0304) or fuel trim
malfunction (DTCs P0171, P0172) or other malfunction
(first malfunction only), is detected.
Because freeze frame data records the engine
conditions (fuel system, calculated load, engine
coolant temperature, fuel trim, engine speed, vehicle
speed, etc.) when the malfunction is detected,
when troubleshooting it is useful for determining
whether the vehicle was running or stopped, the engine
warmed up or not, the air–fuel ratio lean or rich,
etc. at the time of the malfunction."

with a CEL lit up it's much easier, because the freeze frame can be pulled and all engine conditions are known when the DTC was triggered.

but anyways, i think you're right as description of DTC 300-306 doesn't mention 2 trip logic, so it should be instant (CEL should also be blinking when it happens).

 

bottom line of my point is I would drive the car a little locally (until fully warmed up) at various RPMs to see what codes might come up.

Misfires can be caused by lots of things:
Ignition system
Injector
Fuel line pressure
EGR
Compression pressure
Valve clearance not to specification
Valve timing
Manifold absolute pressure sensor
Engine coolant temp. sensor
Open or short in engine wire
Connector connection

If I were you I would download SFI and Diagnostics manuals from camrystuff.com and start checking things per FSM.

 

Just double checked , using my 99 Avalon manual as reference. I oversimplified, as all I've ever experienced on a Toy is the flashing.

The severity of the misfire drives the response. "Frequent" (=>one per 200 engine revs) gets the immediate, flashing MIL response. "Occasional" (once per 1,000 revs) is two trip, solid light.

 

ah, gotcha, now it makes much more sense as we both were right

 

Aren't you supposed to be using dual-electrode spark plugs like these?

 

That's just Toyota's opinion. What do they know about engines?:dunce:

 

it's not obligatory (recommended for spark plug longevity though), but some people prefer single electrode Iridium-IX over Laser Platinum (dual electrode). I guess it should not matter much until the part is listed compatible in NGK part finder tool (affects life span of product though).

 

It has original NGK standard plugs, and I was wondering if the laser platinums would cause the engine to perform better?

That's just Toyota's opinion. What do they know about engines?:dunce:

Seriously, because I am going to change them soon in Auto Tech class, currently it has NGK standard plugs. I don't know how because they are original, and on the engine firewall it states only to use dual-electrode plugs.

Thank guys:thumbsup:

 

if you decide to change them (rear bank is a pain, intake plenum must be pulled on 1mz-fe) you can get Laser Platinum, just in case the plugs are causing trouble.
They say NGK LP can last up to 100k miles with no problems, while Iridium-IX (or standard plugs) could be lasting like 30k or so (rough estimate).

 

Ok, thanks, I will get Laser Platinums (expensive $10 each), makes me wonder how the standard plugs lasted so long?

I'm not worried about difficultly, at my HS we have every Snap-On tool you can imagine.:naughty:

Thanks again:thumbsup:

 

:thumbsup: good luck

 

Well I pulled the plugs back out, gapped them, and popped them back in. Engine still rough and misfiring. Still no check engine light. I installed the old plug wires and it was still the same. I didn't get a change to test those coils but my CEL is back on. Now I'm showing general misfire code as well as misfire in cylinders 1 3 and 5, the back ones, which leads me to believe the coils are indeed weak and barely enough to fire the 3 front cylinders on which they are installed. Will update later. Go to go to work.....

 

ok, it's something.

when random misfire P0300 shows up together with other cylinder specific misfire it means it occurs at same time (random misfire on all those cylinders).
since your misfiring cylinders are all in the rear bank (1,3,5) then I would say ... replace the intake manifold gasket, perhaps it's a vacuum leak affecting all of them?

it's unlikely that all 3 coils are causing trouble (and only to rear bank while front is good, that's suspicious) at same time out of blue moon. but test them regardless. procedure should be described in SFI manual.

 

I note that in the first post, the reported specific misfire codes were for 3,5 and 6.

Now, 1, 3 and 5.

Typo, or new data intended???

The coils are a low failure rate item. To have all 3 of them fail at about the same time? Unlikely.

Look for something they have in common, like the igniter (wiring). You don't bother to give year, so exact equipment is ????

 

Yes, before I installed plugs/wires, car ran fine but had CEL light on with the codes I listed earlier in the thread. Now I'm looking at codes 1, 3, and 5. Thats what my code reader is reading. Its a 1996 Camry LE 3.0L 1MZ-FE V6 engine car.

 

Did you double check, and then check again, that you have the cables running between the right pairs of plugs?

 

1-3-5
2-4-6

Wire positions:
() = paired cylinder

1(4)-3(6)-5(2)
2(5)-4(1)-6(3)

Those are the correct pairings for the wires.

So, ensure the front coils are driving the correct paired cylinder on the rear bank. Cylinder 2 should go to 5, not cylinder 1, and so on.

 

The coil is a common problem on the gen 3 5s engine. I'm not sure about this setup. I still vote coil, but since this car has multiple coils, I'm assuming it has some sort of ignition control module that tells which coil when to fire. That could be your culprit. My old 94 ranger had the distributorless ignition system and had dual coils, and the DIS module went bad and caused similar problems to what you're experiencing albeit on a totally different vehicle. It gave no code for it, and I could only trace the problem by process of elimination.

 

Well the 97+ 5SFE uses 2 coils with integrated igniters, so it's a little different. The 1MZ uses an external igniter that should be checked as well considering there was a code for the igniter circuit.