Car down on power and misfire, rough idle, mostly in closed loop mode(warmed up)

[twistedneck]

Been noticing a slight misfire at part throttle over the last month.

It has now got really bad.. so bad that I noticed it gets much worse when the car goes into closed loop i.e. when the O2 sensor starts providing feedback after the car is warm. (edit correction: it happens all the time) - Get to a traffic light and it will stumble and fall below normal idle, catch itself.. any type of throttle tip in is a nightmare that causes a serious miss. Not a pop and crack type of misfire, more like a low rumbling and stumbling type of misfire. its way worse in closed loop mode but the other day at idle it was very rough and I had just started it first time that week.

I've been having a P0302 code for a while now and it used to come on every few days, now its instant.

I have checked the cylinder and it looks good, but for some reason the plug on #2, outside rim and ground prong were very rusty (edit: I was wrong, all plugs are equally rusted). I replaced the plugs, all seemed good, until the car warmed up and the dreaded mis came back and it was back to square 1. Cylinder 1 plug was also a bit rusty.. but all other plugs looked normal.

I'm going to log a lot of parameters tonight and try to look for anomalies that would point to an issue.

My first thought was a vacuum leak, but it fine until she gets warm - my LT trims are 1.08 on both banks though, telling me it could be a leak. the ST trims are spot on at idle.

Here is where i'm going

1. MAF? cleaned it and it looks good, but that doesn't mean anything - how can I log this and confirm its OK?
2. O2 sensor? i'm not getting a code but the gradual nature of the failure tell me this could be the cause especially since it really pukes when I get on the throttle.
3. Bad injector on cylinder 2? I have the ford racing 47lbs injectors but after 3yrs on E85, maybe that one gave up?
4. Bad coil? I don't think so, I swapped coils and the misfire stayed at cylinder 2.

I inspected the cylinder it seems OK (edit: I only looked at the lack of oily plug), runs clean, and no smoke at all from the car.

help appreciated, i'll post up the logs here.

Thanks!!

 

[06mach1]

If your misfire stays with cylinder number 2, then you need to look at cylinder 2 components. As you stated, you switched coils and misfire stayed at 2. Eliminates the coil. You should probably look at compression and leakdown in cylinder two. Without replacing the injector for cylinder 2, you should be able to graph the wideband sensor readings for each bank and see if one bank runs rich or lean compared to the other. Chances are a faulty MAF or wideband would effect all cylinders at least on the same bank as cylinder 2.

 

[ArizonaBOSS]

 

[twistedneck]

Thanks guys.

I'll try all of those things tonight / this weekend and report back.

Question, if its a mechanical issue like rings, cracked piston, valve issue, cam, etc.. Wouldn't those normally produce a knock or at least some smoke? Or coat the plug in oil?

 

[ArizonaBOSS]

Typically, yes.

 

[TMSBOSS]

If the issue is a Hard Part; piston, piston ring, valve, valve spring etc.. Would this not be covered under the 5 60 power train warranty??

If so, a compression test and or leak down test will likely show if you want to take the car to a dealer for warranty work.

Am I right on this one? I have not used the power train warranty so I am not sure what is and is not covered.

 

[BigTaco]

This would be under warranty (5/60) if the car has not been aftermarket tuned or has a bunch of engine modifications.

 

[wwilde001]

Once the car starts misfiring, try unplugging the #2 injector to see if the engine sounds the same or worse. If it sounds the same then you probably have found your culprit. As a comparison, unplug another injector to see what it sounds like. I've seen electrical components work fine until they heat up, and then start misbehaving. So if you haven't swapped a coil yet, go ahead and swap it and see if the misfire moves. Good Luck and keep us posted.

 

[twistedneck]

Once the car starts misfiring, try unplugging the #2 injector to see if the engine sounds the same or worse. If it sounds the same then you probably have found your culprit. As a comparison, unplug another injector to see what it sounds like. I've seen electrical components work fine until they heat up, and then start misbehaving. So if you haven't swapped a coil yet, go ahead and swap it and see if the misfire moves. Good Luck and keep us posted.

We got the car idling rough and warm so we then pulled the plug on injector two (the one with the horribly rusted plug). It made no difference what so ever. then, while still running rough we pulled injector 5 and it made a difference causing the car to barely idle.. plugging 5 back in idle rpm jumped up about 100. still running rough due to the unknown issue.

I use E85 with 47 LB M-9593-LU47 injectors. I am worried that they can't handle E85. Is there any place I can buy just one injector and see if I fix my issue? I'm going to try the dealer now.

Edit:

I found the bosch part number for my injector its 0280158279.
http://www.boschdealer.com/product/52lbh-550cc-bosch-fuel-injector-w-ev6-uscar-connector-0280158279/
Here is a pic of my injectors new

This is the only place I can find one single injector.

 

[wwilde001]

You stated that cylinder plug #1 looked different as well. IMO, I'd just go ahead and buy a set of injectors and replace them all. If the E-85 is an issue, you'll be doing the same thing in the near future. I think you can find a set of them for around $300 last time I looked.

 

[twistedneck]

You stated that cylinder plug #1 looked different as well. IMO, I'd just go ahead and buy a set of injectors and replace them all. If the E-85 is an issue, you'll be doing the same thing in the near future. I think you can find a set of them for around $300 last time I looked.

(edit: after looking again all plugs are equally rusted out.) Good idea, even though i'm getting only one misfire code cylinder 1 was also looking bad. I'll change both.. got a pretty good deal on four here.

http://www.ebay.com/itm/310971490732 $166 shipped.

Murphy's law says this wont be the problem, but using wwilde001's 'unplug the injector while its running and see what happens' test the car didn't change at all.. Next week i'll try more items if this does not pan out. Thanks for the help!!!

 

[twistedneck]

If you have access to a boresope, it may be worth pulling the plug to your problem cylinder using an angle attachment to view the valves/ seats. Borescopes have become pretty cheap. I think you can even get one at Harbor Freight. One of the best tools I ever bought being a career mechanic. Unplugging a cylinder's ignition or fuel should produce some effect. IMO, the drivability and diagnoses you are describing might suggest a burned valve. Of course, compression testing is always a good diagnostic tool as well. Good luck.

576, I know there is that risk of a mechanical failure but that dread has not fully surfaced yet. the Harbor Freight bore scope is $189 for the HD version and that's still a tiny screen. Got the leak down and compression test hardware ready to go.

Looking at the SCT last night with the newest Live link 2.0 - there are way to many items to try and log. Only thing I noticed was the O2 sensor bank one had a higher peak and lower lows for the current. bank 2 looked the same otherwise, peaks were about 10% higher on bank 1.

Is there a set of log parameters you recommend? there are so many i'm lost and half of them cause the unit and software to crash, or they just don't work. there are all kinds PID, OEM, etc. etc..

Edit: was talking with one of my friends from the Ford Performance office this morning and they said it could also be some type of failed gasket making the plug rusty.. How would i check that apart from a leak down test?

PS. Got me a cheap bore scope! 8.5mm with mirror.. will fit. Much higher res than the Harbor Freight unit.
http://www.amazon.com/gp/product/B00KJ5TE7G?psc=1&redirect=true&ref_=od_aui_detailpages00

 

[ArizonaBOSS]

I have that same borescope. Be careful with the mirror--it doesn't attach very securely. I used some electrical tape to make sure it stayed on.
Also the camera itself will get very hot with the LEDs turned on after a few minutes.

Image quality is not bad, however.

 

[TMSBOSS]

I hope you do not have a "Hard" part issue; valves, rings, piston. I am curious to know your issue considering the use of E85 if I read correctly. Compression testing is a good start. Leak down testing gives a direction to intake, exhaust, bottom end. I'm sure you know this. If you have switched coils and fuel injectors to other cylinders and your problem cylinder still does not cause a change when disabling fuel or ignition... Good indicator of a mech issue. Be diligent in your basic testing prior to buying parts. In my experience 99.9% of problems fall into the K.I.S.S. standard.

Also check wiring harnesses and connectors. A problem specific to a cylinder can also be related to the wiring harness and or connectors. A good visual inspection of the wiring and condition of the connectors may turn up something.
Have you discussed your issues with your tuner?

Earlier on you asked about smoke. Yes, bad hard parts will usually cause smoking from the engine. Unfortunately, Smoke has to be considerable to get through the cats. A small amount of unburned fuel or oil will be burned in the cats.

 

[twistedneck]

Also check wiring harnesses and connectors. A problem specific to a cylinder can also be related to the wiring harness and or connectors. A good visual inspection of the wiring and condition of the connectors may turn up something.
Have you discussed your issues with your tuner?

Earlier on you asked about smoke. Yes, bad hard parts will usually cause smoking from the engine. Unfortunately, Smoke has to be considerable to get through the cats. A small amount of unburned fuel or oil will be burned in the cats.

(edit: after research i realized that I did speak with Shaun about my P0302 codes and P0300 but that was before our E85 stuff) Yes, a couple years ago after I had been on E85 for a while I mentioned the misfire code P0300 and P0302 to Shaun at AED my tuner. he said its unknown and my engine seems fine but I need to figure out what's causing it. Now the code is P0302 only and its causing the issues outlined above. I would get the P0302 code here and there then it became weekly, daily, and now its actually a few minutes running and it throws the code. that rusty plug on cylinder 2 is telling us something - what I don't know. I don't run stabil so one theory is the fuel is leaking out of the bad injector and drawing in water especially during the long winter storage period. Other theory for plug is a leaky or cracked head. The other theories about burned valves and other mechanical issues would not cause that rusty plug.. also the plug had no oil on it.. the ceramic around the electrode looked brownish (rich) like all the others since i'm running rich all the time - Shaun tuned me on pure E85 from the drum, and in Michigan I only get that for July / August - usually its E70-E75.. so she is almost always running rich.

I run E85 w/o cats - so I should see some smoke! i'll know more on Monday / Tuesday when I swap injectors and bore scope the cylinder.

One note, this slight misfire started to be felt on part throttle cruise on way to work a few months ago, and just last month I set my PB at the drag strip so it was not down on power or smoking during that time. but as we all know, I could have cracked rings and they are just acting funny! if that's the case i'll put rods and pistons on there and make it a quickie 12.5:1 e85 rebuild, put the livernois springs on keep the rest the same and hit 8200 rpm! so i'm not going to be crushed if its a cracked ring land.. but that would shut down my summer driving :-\

 

[TMSBOSS]

"Rust" on a plug is usually not "Rust"
Fuel additives will leave a rust or ashen look on plugs, normally all the plugs not just one.

From my experience, any rust on a plug or in a cylinder disappears once run.

Is there any discoloration of or oil in the coolant? Any bubbles forming in the coolant?

Have you talked to Shaun recently?

 

[twistedneck]

"Rust" on a plug is usually not "Rust"
Fuel additives will leave a rust or ashen look on plugs, normally all the plugs not just one.

From my experience, any rust on a plug or in a cylinder disappears once run.

Is there any discoloration of or oil in the coolant? Any bubbles forming in the coolant?

Have you talked to Shaun recently?

No contact recently but i'll send him an email (show him this thread). Oil looks normal. this year I changed from Mobil 1 gold 5W-20 to redline racing 10W-30 high zddp. I have heard that can mess up your O2 sensor but that's rare?

Agreed, 'Rust' does not survive high temperatures. it looks more like heat treat scale to me but hell who knows what E85 / oil / coolant / combustion is doing to that plug! I'll look at the coolant again, where is the best place? the overflow tank in front is easy to get to.

 

[twistedneck]

Update:

I looked back and the first time I got the P0302 code was before I changed to E85. back when I swapped cams after the winter of 2012/13. I was getting P0302 and P0300 every couple days. There was no misfire detectable at idle or while driving, just these codes.. for what ever reason I don't know if this new issue is related to that root cause or not!

Shaun stated he has seen a lot of brown E85 sludge build up on injectors depending on where you get the fuel, especially if you let the car sit. a lot of stations converted to E85 from Diesel and there you go.. its a brown sludge I need to look out for at the bottom of the injector and possibly clogging the holes. He also said there was internal sludge that still caused the car to misfire at idle after cleaning but that went away with a little more gasoline running. To keep this from happening I need to cycle gasoline through more often, store using stabil, etc..

I'm wondering now if the P0302 and P0300 I got before were related to something different, and this new version of the code is related to the injector? i'll go pull them all now and find out

 

[2012Boss302]

Did you swap injectors yet ???

 

[twistedneck]

Did you swap injectors yet ???

Not yet, going out to remove and inspect injectors now. Take pics. New ones come in Tuesday.