[Richtazz]

Hello all, new member, first post!

I just bought a used 2013 VT, 88k miles, 6 speed manual, well taken care of, clean car-fax. No known mods other than a K&N air filter element in stock housing with stock air intake. Driving home, car developed misfires, worse under hard acceleration. At steady speeds car ran fine, got 34 mpg on expressway trip home. After reading some posts, I changed the spark plugs due to mileage. It seemed to help at first, but misfires returned. Plugs removed had a bit of brown discoloration, but not burned, wet, caked with deposits or any damage to ground electrodes or porcelain. Gaps only slightly larger (maybe 0.035" max) than those on replacement plugs (0.028"-0.030", carefully checked with feeler guage, as I know from my 33 years in the auto parts business that re-gapping Iridium plugs can cause more problems than a few thou variance will) After reading some posts on here about possible coil pack and low-pressure side fuel supply line issues, I hooked up my scan tool. The only codes I have are for misfires, including all 4 individual cylinders (P0301-P0304) and P0300 random, no P0087 low fuel pressure, yet scan tool indicates only 560-580 psi fuel line pressure at idle, and it stays flat with a only a little variance up and down as rpm is increased to around 3500 in neutral (not gonna free-rev it higher than that). Not having much experience with Hyundai (if you need GM vehicle info, I'm your man,...) I humbly turn to you all for help and advice, so as to not throw away money on things not necessary. I ran my VIN on Hyundai's site, and it does not show any recalls or campaigns relevant to it. Thanks in advance for any and all help.

 

[Richtazz]

Thanks for the reply. I will run my scanner tomorrow while driving, record fuel pressures under load and post back. So you're saying these cars do not like regular 87 octane even when stock even though the owners manual says it's okay?

 

[Richtazz]

Okay, good to know I need to run better octane from here on out. Thank you for that info.

I hooked up my scan tool this morning to watch the readings and record them, but for some reason the recording stopped only a few seconds after I started.

Upon glancing at the readings as I continued to work, the fuel pressure moved around, generally between 560-1500 psi, with no misfiring issues under light load acceleration, keeping revs under 3500. The one time it spiked up a higher is when I rolled on the throttle in 6th gear around 45mph. Under that load, the pressure spiked to around 1950-1960 psi, and the engine stuttered, but it didn't trip a permanent misfire code. Does this still sound like bad coils or possibly a fuel delivery issue?

Again, thanks in advance. If it would help, I can upload a picture of the old plugs I pulled out when I get home tonight, although I saw nothing on them that really showed anything (light brown color and even, non-excessive wear/gap erosion/no cracks in porcelain, etc... Let me know

Rich

 

[Richtazz]

Hmm, interesting. The "up-shift indicator" starts nagging if I don't shift to 6th at that speed while steady cruising on flat ground. To clarify, all I did was slightly roll on the throttle to induce a load once I reached a steady speed. That is when the hesitation occurred. It was not a typical "lugging the engine"
in too high of a gear feel. No attempt at hard acceleration. Again, I really appreciate any and all responses.

Also, I hate sounding like a noob...

Rich

 

[Richtazz]

So, what information do I need to provide to try and narrow this down? Do I need to more closely monitor fuel rail pressure readings vs rpm and post them here? If so, I will try to get the record function to work on my scan tool so I can do so more accurately.

I can say that fuel pressure under normal acceleration stayed under 1300 psi. Do I need to get on it a bit and get the tach above 4k and see what happens then?

It only spiked into the 1900's when I lightly rolled on the throttle (not hard enough to physically lug the engine) in high gear and that's when the hesitation occurred.

I've read fuel rail pressures in the >2k psi range under load are not abnormal. Is that information erroneous as well?

Is there an ohm spec for the primary side of the coils that I can test, or is that not an accurate test due to the coil-on-plug design?

Again, any help would be greatly appreciated.

Rich

 

[Richtazz]

You should see ~2150-2175 PSI (~148-150 bar) at WOT.

Ignition coil resistance specs are in the service manual.

Thank you very much, this is the info I was looking for. I will be getting a manual for this car in the future (I see PDF versions available for a reasonable price), but since I just bought it, I don't have one yet.
Rich

 

[Richtazz]

Okay, left work today, all is good at first. Booted it a couple times, fuel pressure good (climbed well past 1800 psi), no misfires, runs great up to 4,500-5,000 rpm through 3rd gear and pulls strong.

After a couple of more miles, I get another opening from a stoplight, boot it again, runs fine through first and second, hit third fuel pressure quits rising at just over 1k psi and flutters a bit, engine bogs, then the CEL flashes, but goes back out when I let off and it stays off.

Car drives rest of way home fine since I didn't get on it again.

It definitely seems the issue is fuel pressure related, so does this sound like the low pressure line issue, or could it be with the high pressure pump at the engine?

 

[Richtazz]

I just bought the car, and have been having mis-fire issues when you get on it. No P0087, just P0300-0304 codes.

Changed spark plugs due to mileage but no improvement. Definitely seems to be fuel related as fuel pressure stops climbing with engine speed after driving a few miles.

No obvious mods other than a K&N drop in air filter in stock airbox.

 

[Richtazz]

To answer E9C900A,

Car has 88k miles, great shape, clean with well documented carfax. Sat on dealer lot for a while through the winter due to disinterest in the Matte paint and manual trans.

Ran fine at first, then the misfires started after pulling out of a rest area and getting on it to merge with traffic.

Changed plugs when I got it home due to mileage and not knowing if they had ever been replaced. Old plugs came out clean and dry, just normal light brown deposits. No gas, oil, burnt ground electrodes, etc... Ran good at first after plug swap but misfires returned after a while.

After warming up a bit, when on the gas over 3,500 rpm, the fuel rail pressure stops climbing (normally not until 3rd gear) at around 1.1k psi, and then the CEL flashes misfires. When driven lightly, car runs flawless, smooth as butter, got 35+ mpg at 75mph on trip home, never registered another mis-fire all the way home, nor in normal driving now trying to sort it out. Only mis-fires when the fuel pressure drops . Only other thing of note, there are light black sooty deposits on tailpipe outlets.

 

[Richtazz]

I really appreciate everyone's input. I used to be a moderator on another car forum for GM cars, and I know it always made me feel good when I could help someone. I will be doing the fuel line replacement this weekend, and have ordered the coils (may get here Saturday for installation this weekend as well). I will boroscope the cylinders, do a compression check and post all results here.

In case anyone thought I was searching for a "cure in a can" or something, that is not the case. I tried to present my issues as clearly and detailed as possible, as I know that is the best way to get the right advice. Just didn't want to throw money away on things not needed. You guys are the experts on this model, I am but a humble noob.

Thanks again everyone!
Rich

 

[Richtazz]

No problem, everyone was new once.

If you have a multimeter, check the electrical resistance of the main grounding points (both strut towers to start) and report back with this info, please. Pics are best to confirm ohm values.

I read where Hyundai attached the grounds to the body without scraping paint. I took both strut tower grounds off, and scuffed the paint to bare metal and reattached. Should I also do the one I can see by the overflow reservoir with the odd looking multi-wired connectors attached?

Do you want me to detach the grounds and read the resistance between them and where they mount to the body, or am I testing something else?

 

[Richtazz]

okay, here are the photos you requested E9C900A.

battery to d-side strut tower

battery to p-side strut tower

Cyl 1 coil

Cyl 2 coil

Cyl 3 coil

Cyl 4 coil

Meter baseline (touching 2 leads together)

Also, is the OBDlink MX worth the extra cost for these cars over the OBDLink LX? I have a portable scan tool that can run live data but the record/playback function is trash, I think I would like the ability to log things as I have read these can do.

 

[Richtazz]

The coil measurements are across the two terminals where the harness plugs in (primary side) just for clarification

 

[Richtazz]

Not sure if your multimeter is rounding up, but the maximum value is .9085 ohms as per the service manual:

However, as we all (should) know, resistance values rise as air and material temperatures rise. Spec value is at 68°F.

The coils fixed it. Since winter has decided to return to the murder mitten (Michigan), I will wait until better weather to do the fuel line, but it will be getting done as well. After swapping the coils (new ones ohmed out at 0.8 vs 0.10 on the old ones), I took it for a test drive. It now pulls clean all the way past 5,500 rpm through 3rd, 4th, and into 5th without a hiccup. I guess, since the HPFP is mechanical, the fuel pressure dropped because of the misfires rather than vise-versa? Anyhow, thank you so very much to everyone, especially E9C900A for all the great advice. It's nice to have her running as she should.

 

[Richtazz]

Well, the misfires have returned. A few good days, and now it's undrivable trash. Forgot my scan tool at work, so no idea what is causing the issues now, but it's worse than ever. New coils all still check out fine (primary side anyway, didn't check secondary resistances) I still think it's fuel related, but just guessing since I couldn't scan it. FML.

 

[Richtazz]

I delayed the fuel line replacement when the new coils arrived and the car was running well due to the weather. I loaned my scope to a mechanic friend, so I cannot scope the cylinders yet.

The replacement coils I bought (Standard Ignition Intermotor line, as my local dealer didn't have any OEM available for a week) are what caused the latest issue, went bad in 3 days. All 4 are already out of spec , primary spec okay, all are .08 ohms, but way low on the secondary side (5.48k, 3.55k, 5.55k, and 5.48k).

The oddest issue now, is I cannot get a secondary side reading on my original coils I took out. The primary side all still read 0.10 (with a .01 correction factor on my meter, so borderline high end of acceptable .09 ohms), but the secondary side shows open on all 4, yet the car was still running on them, admittedly not well.

 

[Richtazz]

Learned my lesson, will get OEM coils on Saturday...spendy little rascals. Paying my pittance, having to drive the wife's minivan for a couple days. Soccer practice anyone? :wink:

 

[Richtazz]

Okay, sorry about the delay in responding. The OEM coils fixed the misfires and the car is running well. Compression test was done and all cylinders are well within spec (all were with a few psi of each other in the 185-190 range) after warm up and with coils and fuel pump disabled. Boroscope not done, as my mechanic "buddy" broke mine ( I know better than to loan people my tools...grr!), so I'm waiting for him to replace it. Since the car is running well now, I am less concerned about it's need to be done, but I still want to do it.

I want to now address the mods needed to address the factory issues.

I have seen differences of opinion on the oil catch can mod. Some have said PCV valve side, some say breather side, some say both. I do not want an oil choked turbo or intake valves, so suggestions please.

On the clutch pedal mod, what exactly does this do, defeat the "rev matching" ECM programming that from what I have read seems to cause a hiccup in the 1-2 shift making that difficult to do smoothly?

On the torque app for the OBD-Link MX. Does anyone have a good write up or website I can visit to learn this program better? The OBD-Link MX is a pretty impressive little device I must say. Also, is there any app that would make it ABS compatible?

Lastly, I am blessed to know my dealer's parts people and one of their service guys personally through work. They told me that this upcoming recall will most likely affect my car since it's a 2013, and may even get me reimbursed for the coils. We will see on that.

So, thanks again to everyone that has answered my past questions, and thanks in advance to any and all that answer my new ones. This forum is an excellent place to go for answers.

Rich

 

[Richtazz]

THIS: https://www.velosterturbo.org/forum/veloster-performance/26906-breather-pcv-discussion.html

That is one looooooooooong convoluted thread. So many different opinions and "solutions" to the issue of oil vapor coking. At first I thought why put a catch can on the breather side, that's incoming air... until I read how these turbos start venting through the breather side as vacuum drops on the pcv side and it closes (excess CC pressure has to go somewhere). So much info, but good info to have for a forced induction noob like myself.

 

[Richtazz]

So, Cerma engine and Nano treatments ordered (Cerma included a free fuel treatement also) with nice discount using promo code xeperformance (Thanks E9C900a for posting a link in another thread), and catch cans to be ordered this week as soon as I can get in/under the car to find a good mount location so I know what physical size cans to order (as these cars have almost zero room under the hood). Car is still running well, and I want to keep it that way.

Do you recommend running a pressurized intake valve cleaner through to get rid of any possible carbon deposits considering my mileage (88k)? Thanks in advance.

Rich