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Hey everyone, so I've searched the forum like crazy and have a good amount of troubleshooting to do, but figured I'd ask here as well. I have a 2013 7AT with 85,000 miles on it. I replaced the battery about 2 weeks ago as the old one died on me. Today I went to start the car (this was a warm start, car had been sitting maybe 20 minutes after being driven about 30 miles) and the starter sounded like it was really struggling to turn the motor over, similar to how it may be in the cold when you have a weaker battery (I'm in FL and it's 77 degrees). When the car did start, which was still on the first attempt, it started misfiring all over the place, trying to stall and the RPM's were very sporadic. It immediately threw p0300. I had to limp the car back home with my 2 year old in the back (parents will understand the importance of making it home by naptime lol).
The car cleared up a bit on the highway but I took it easy and tried to stay under 3k RPM the whole trip back. I was logging the car with Torque and watching the misfire counts while driving, which weren't honestly as high as I'd expect considering how bad the car had ran when I started it. I'm showing about 34 misfires on cylinder 1, and then under 10 on cylinders 3, 4, and 5. Nothing on 2 or 6.
I can understand a random misfire, but the weird starting issue was really strange. Anyone ever experienced that before getting a bad misfire? I did double check the battery terminals in the parking lot, and those were nice and tight, and the battery was at 14.7v while the car was running, so I know it was getting juice from the alternator. I'm going to order plugs, check fuel pressure when I can snag a rental gauge, and check for vacuum leaks, but any ideas?
Quick recap for those that don't like to read a lot (Sorry, I type a lot)
Car struggled to start, as if the motor didn't want to turn over
bad misfire after starting, thew code p0300 and no other pending codes (rescanned several times during the drive cycle)
Misfires showing on Cylinder 1 the most, but also present on Cylinders 3, 4 and 5
new battery as of 2 weeks ago, terminals are tight and battery showed 14.7v at idle on my multimeter, 12.13v with the car off at home.
Not sure if related at all but I had similar issue. I bought a new battery all seemed well for a week. Then warm start she quit. Tried to turn over couldn't. So I clutch bump to start and she bogged crazy. So I had starter tested and it was weak. Replaced starter and all issues cleared up. Does she start ok now? Are you spark plugs original perhaps the o rings failed allowing oil in the tube.
Okay, so I went out and did some more investigating while the little one is sleeping, and here's what I've found:
- no vacuum leaks (sprayed TB cleaner on every visible vacuum line and on as many of the injector seals as I could get to
- Battery key off is 12.13v, after another drive around the block with the car running, battery voltage is only reading 13.1v now, so I am wondering if maybe there is an alternator issue going on.
- Could not get the car to "hard start" again after 20+ cycles of the motor. it starts right up each time like normal.
- I cleared the codes and the SES has not set again, but while watching the tach, I can see the RPMS drop in park from 700ish to about 500ish, and the motor starts to stutter.
- When the RPMs drop, I can hear a top-end tapping noise that sounds like it's coming from the 1-3-5 bank. When the RPMs raise back up, this clears up and the motor sounds like it's normal "sewing machine". I'm used to pushrod engines, but when this noise occurs, it sounds like lifter tap, and of course the motor is shaking a bit while it's doing this. Is this normal behavior/noise to expect with misfires? Since most of the misfires were on this bank of cylinders, it would make sense that as the motor starts to misfire, RPMs drop, but I've not heard a noise like this with a misfire before.
The plugs are original to the car as far as I know, so I am going to swap those, clean the TB's, perform an idle-air re-learn, clean the MAF's, and see what happens from there. Anyone have experience with Autolite plugs? Of course the Denso OEM's aren't in stock anywhere in my area, so they are about the only iridium plug I can get short of waiting until next week for shipping. Car needs to be back up before the end of Wednesday, so I'm going to have to bite the bullet and use autozoo parts for now.
My brand new batt only reads 13v on the torque app. Some say the alt doesnt charge until 14 miles of driving. Still dont think its batt or alt. If no more hard start it may be engine issues
Okay, so I went out and did some more investigating while the little one is sleeping, and here's what I've found:
- no vacuum leaks (sprayed TB cleaner on every visible vacuum line and on as many of the injector seals as I could get to
- Battery key off is 12.13v, after another drive around the block with the car running, battery voltage is only reading 13.1v now, so I am wondering if maybe there is an alternator issue going on.
- Could not get the car to "hard start" again after 20+ cycles of the motor. it starts right up each time like normal.
- I cleared the codes and the SES has not set again, but while watching the tach, I can see the RPMS drop in park from 700ish to about 500ish, and the motor starts to stutter.
- When the RPMs drop, I can hear a top-end tapping noise that sounds like it's coming from the 1-3-5 bank. When the RPMs raise back up, this clears up and the motor sounds like it's normal "sewing machine". I'm used to pushrod engines, but when this noise occurs, it sounds like lifter tap, and of course the motor is shaking a bit while it's doing this. Is this normal behavior/noise to expect with misfires? Since most of the misfires were on this bank of cylinders, it would make sense that as the motor starts to misfire, RPMs drop, but I've not heard a noise like this with a misfire before.
The plugs are original to the car as far as I know, so I am going to swap those, clean the TB's, perform an idle-air re-learn, clean the MAF's, and see what happens from there. Anyone have experience with Autolite plugs? Of course the Denso OEM's aren't in stock anywhere in my area, so they are about the only iridium plug I can get short of waiting until next week for shipping. Car needs to be back up before the end of Wednesday, so I'm going to have to bite the bullet and use autozoo parts for now.
If you like your car only oem denso plugs. No ebay not auto lite not ngk.
DENSO ONLY
Looks like ConceptZ is the best online source for the Denso plugs, it's just ship times with the holiday. Autozone can't get them to me any quicker though, and I'd rather not put in a plug that my car won't play nice with. The last thing I want is more issues masking the cause of the current issue I'm having lol, so looks like I am going to order some Denso's and hope they can get here by the end of the week.
I'm going to clean my throttle bodies and MAF's tonight and see if that makes any difference.
You sure you dont have small cracks in vacuum lines? Spray soapy water or window cleaner on lines to look for bubbles
I can definitely go investigate more with soapy water. I shot all of the lines with carb cleaner pretty good and didn't notice any changes in idle.
The only line that was strange was the "pcv" line on the drivers side that goes from the front of the intake to the PCV valve itself. It has a rubber shroud on it, I'm assuming to protect for heat, and when I squeeze in on that line it does stop a slight air sound I can hear. I pulled that line off and pulled the shroud completely off and don't see any cracks or pinholes at all. I even plugged one end and put soapy water inside then pressurized it with my compressor and didn't see any leaks from it at all.
Edit to add a video to the vacuum line I'm talking about. The video makes it sound a lot louder than it is, but I could not get the line to bubble with soapy water or react to carb cleaner.
So would a battery or alternator cause a misfire like this? I cleaned my MAF's last night, and have been checking the voltage to keep an eye on the battery because of the hard start yesterday. Battery voltage with the car off today was 12.04v, so I'm thinking the battery may be bad or the alternator isn't charging properly. I'm going to take the car to have them both tested once I get the new plugs, TB gaskets, and TB's cleaned this week, but could that cause this issue?
Also, does anyone know the part number for the hose in the above video? All of the diagrams I've found on Infinit's parts sites don't have that hose listed, only the ones that are under the airbox.
So would a battery or alternator cause a misfire like this? I cleaned my MAF's last night, and have been checking the voltage to keep an eye on the battery because of the hard start yesterday. Battery voltage with the car off today was 12.04v, so I'm thinking the battery may be bad or the alternator isn't charging properly. I'm going to take the car to have them both tested once I get the new plugs, TB gaskets, and TB's cleaned this week, but could that cause this issue?
Also, does anyone know the part number for the hose in the above video? All of the diagrams I've found on Infinit's parts sites don't have that hose listed, only the ones that are under the airbox.
no but it can cause start issues if your battery is OEM check the water level in the cells and refill with distilled water if low. Check the multiple grounding straps to see if they are loose or damaged
I figured as much, just coincidental. It's not the OEM battery, but it is less than a month old and has warranty, so if it's bad already it will get swapped out for free. Looking back at my voltage numbers though, it seems to be on the low side when running (13.1v running), so I am hoping my alternator isn't on the way out.
I figured as much, just coincidental. It's not the OEM battery, but it is less than a month old and has warranty, so if it's bad already it will get swapped out for free. Looking back at my voltage numbers though, it seems to be on the low side when running (13.1v running), so I am hoping my alternator isn't on the way out.
running 13-13.3 is the range. Do a load test free at autopart stores to check alternator and battery
Ok, so I'm cleaning up the TB's and changing out the plugs tonight. Can anyone confirm if the amount of oil on the #1 plug is normal? The car has 85k on it. The spark plug well on the #1 cylinder was dry, only the threads have oil. The #3 and 5 plugs do not have any oil on the threads.
#1 plug has a lot of oil on the threads and looks to have been running lean.
#3 plug has no oil on the threads and looks to have been burning evenly.
Can anyone confirm if this is an OEM coil? They have a V embossed on the very top.
I also ordered two used coil packs from Z1 just to have for troubleshooting. At $40 each for known good OEM coils, it can't hurt to keep some spares in the trunk. All the coil packs looked visually fine with no blistering like some of the vq35 coils were known for. On thing I noticed is that the ground cable on the battery doesnt want to stay tight to the terminal, so tomorrow when I can borrow my wife's car to charge the G's battery enough to do an idle relearn and throttle position relearn, I'm going to take it to have it load tested and pick up some battery shims too.
12-30-2019, 01:40 PM
