Testing Ignition Coil

[anchorshot]

I have a 04 Ranger with the 3L V6.

The CEL came on and I pulled the codes: P0301 and P0316

I am thinking that it could possibly be the ignition coil. I was wondering what the correct way to test this is and what numbers I should get while testing to know if it is indeed the coil.

If anyone has any other ideas of what could be causing these codes please chime in.

Thanks in advance.

 

[kimcrwbr1]

Is the coil grounded good take it off and clean it good check the connectors and wires also.

 

[Hotrodlincoln]

Is it misfiring/stumbling or did the CEL just come on with no symptoms?

Also guessing you meant P0306 not P0316. Not sure when they started putting 16 cyls in the Ranger, must be that German version the compete with Audi?

 

[anchorshot]

Is it misfiring/stumbling or did the CEL just come on with no symptoms?

Also guessing you meant P0306 not P0316. Not sure when they started putting 16 cyls in the Ranger, must be that German version the compete with Audi?

Sorry for lack of info. It misses/stumbles bad when first started. Idles very rough. After about 3 minutes its fine. It misses/stumbles again when in gear around 2K RPMs. After running for a while though, it idles fine. Will still miss in gear when you put to much stress on it.

No code P0316 is right. Miss fire detected within first 1k revolutions I believe it is. I've also gotten codes telling me that both banks are running lean. I checked for vaccum leaks and tightened everything. Havent had those codes reappear since.

 

[BRUTUS_T_HOG]

you use an ohmmeter to test the primary and secondary(if it applies) windings. if you own an adjustable KV tester this will help out a lot. naturally an ignition scope would tell you instantly.

here is MY question does a 2004 actually have a 3.0 in it? i know the 4.0l's have problems with lower intake seals leaking when cold and being ok when hot.

anyways yeah missing under load is usually an indication of an ignition problem, what kind of condition is the spark plugs, and plug wires in?

 

[anchorshot]

you use an ohmmeter to test the primary and secondary(if it applies) windings. if you own an adjustable KV tester this will help out a lot. naturally an ignition scope would tell you instantly.

here is MY question does a 2004 actually have a 3.0 in it? i know the 4.0l's have problems with lower intake seals leaking when cold and being ok when hot.

anyways yeah missing under load is usually an indication of an ignition problem, what kind of condition is the spark plugs, and plug wires in?

New plugs about 10k ago. Wires look to be in good condition.

**Im positive its a 3.0, its the Edge model. 2wd

 

[BRUTUS_T_HOG]

the plug wires can have invisible flaws and are almost always damaged by spark plug replacement if they're old. how old are they? does it have a cap & rotor and how old are they if so?

they can leak voltage to ground and short out, causing a misfire. this happens more and more under load when firing voltage is highest.

 

[Rearanger]

It misses/stumbles bad when first started. Idles very rough. After about 3 minutes its fine. After running for a while though, it idles fine.

I'd investigate leaking injectors that flood the engine while shut down (worse on overnight shut-down). They initially will produce too rich mixture on cold start-up that clears quickly. I'd remove the plugs overnight to allow any leakage to evaporate. Install plugs just before start-up and see if you still get the same symptoms.

 

[anchorshot]

Ok, ill change my wires today to see if that fixes it, if not ill take out my plugs for the night. Thanks for the input so far guys. Greatly appreciated

 

[anchorshot]

Ok....so. I changed all wires and removed plugs as suggested. Nothing. All the plugs looked good when I had them out.

I still get misses when in gear from about 1.5k-2.5k RPMs.

The CEL hasnt come back on yet but I'm sure its only a matter of time.

Is the ignition coil the next step?

 

[Rearanger]

It misses/stumbles bad when first started. Idles very rough. After about 3 minutes its fine. After running for a while though, it idles fine.

After leaving the plugs out for the night did the above symptoms still return at start-up?

 

[BRUTUS_T_HOG]

After leaving the plugs out for the night did the above symptoms still return at start-up?

if fuel was leaking into the cylinders with would not stay there, it would leak down into the crankcase through the rings.

OP- it could be an ignition coil but it could also be the fuel system going lean.. does it miss under ANY load or only in a high gear and low rpm?

 

[Rearanger]

if fuel was leaking into the cylinders with would not stay there, it would leak down into the crankcase through the rings.

That would happen if this was direct injection, but the injectors spray fuel into the intake. As well not all intake valves will be open to allow fuel into the cylinder. But with too rich even at start-up there will be fuel in the oil and this can be detected in oil analysis.

 

[BRUTUS_T_HOG]

That would happen if this was direct injection, but the injectors spray fuel into the intake. As well not all intake valves will be open to allow fuel into the cylinder. But with too rich even at start-up there will be fuel in the oil and this can be detected in oil analysis.

the fuel will evaporate out of the intake. the time it would take for any fuel that collected inside the intake to be sucked in, burned, and sent out the exhaust would be too fast to even cause i rough run. anyways, you JUST said to remove the spark plugs so the fuel will evaporate out of the cylinders. and now you're saying there is no way it can get into the cylinders.

the OP is saying it misses under load at roughly 2k rpm. sounds like an ignition problem to me, he's already changed plugs and wires, so he needs to test or replace the ignition coil to rule it out

 

[Rearanger]

It misses/stumbles bad when first started. Idles very rough. After about 3 minutes its fine.

I'm not sure how that relates to an ignition problem. But there may be more than one unrelated issue. You're right though that I said no fuel would get into the cylinders after I said remove the plugs - so complete understanding of the process is lacking. As for evaporation from the intake, that would be slowed down when the throttle plate was closed. Maybe holding open the throttle plate overnight would help.

Here is a comment from another forum on this:
"I agree with Rezinn. I had leaky injectors and I confirmed that by pulling the plenum and runners off, popping the fuel rail up so that the injectors are clear of the manifold (use of a small wooded block to support the rail assembly is helpful), then put paper under each injector and prime the pump (turn the key on - DO NOT START!). I had gas instantly on 7 of 8 injectors, with a couple actually pooling on the paper - not good!!

The symptoms... really hard starting after the car sat for more than 10 minutes (except for the very first cold start of the day - always started first crank). The gas leaks down into the sylinders and floods them - if I restarted within a few minutes (like when gassing up) it would start OK, but if it sat for any length of time it had to crank and crank - sometimes I would floor it to clear the flooded condition. Had the injectors rebuilt and it starts good all the time."