Issues with 2010 Camaro SS misfiring after spark plug & spark plug wire replacement

[morepowerjoe]

A simple fuel pressure gauge at the end of the fuel rail would of told you if the fuel pump was the problem. And a good scan tool or hp tuners would allow you to disable each injector one at a time or just pulling the spark plug wire one at a time would tell you which cylinder is down. Knowledge is power.

[Joe.G]

Fuel pump had nothing to do with your issue but if you wanted to change it that's on you I bet if you didn't change it your fuel gauge wouldn't have broke. You could have swapped injectors around to rule them out and cleaned them or had them cleaned many pumps and injectors go multiple hundreds of thousands of miles. Gapping iridium plugs can cause it's own set of issues if not done right. If you can change plugs and wires why did you pay dealership to do it? Expensive lesson this has turned out to be. Now I am going to bet the issue is wire/ connection being wiggled or moved during install and there's a bad connection that will present it self again. Maybe it's a coil connection and that will be corrected on install. Hard to tell from my computer.

[bsn]

Not trying to bust your chops but your in complete denial. Your fuel pump was never the problem, and I doubt the fuel injectors were either. The sender didn't wear out or fail suddenly it was either damaged during removal or it was a loose connector/pinched wire.
Delphi is a GM brand and is a quality part but on EBAY who knows what you really got. You need to find a reputable shop to work on your car and stay far far away from the ones you have used.

[Camarosmith]

another thing that is strange about this situation is when I put the ebay spark plug wires on the car was great for about a week and a half with no issues until I took a 30 minute trip with the car on the freeway

and another strange thing about it is that the misfire issues stopped except on a cold day startup when I put the ebay double platinum spark plugs in it would only misfire if it was really cold out and the engine got cold

I later removed those and put the iridium's back in cause I wanted to use the spark plugs that were made for the car and iridiums are supposed to be higher quality & longer lasting but they were the 10-162's the chevy dealership installed and replaced cylindars 6 & 2 with brand new identical ACDelco 41-162's only to still have misfires on those cylinders mostly cylinder 6 Then I found and went and got the ACDelco 41-110's that were said to be discontinued and replaced by the 41-162's ( and they are slightly different as they are the same size yet the 41-110's have a pointed tip instead of a round flat top on them only to still have misfire issues.

In other words the car almost ran great on the ebay double platinum spark plugs except for cold starts on cold days, other then that no misfires once it was started and no issues on long trips unless the car sat again in the cold on a really cold day which it has been really cold lately cause its winter this is also weird to me.

I never suspected the fuel pump to be the problem, I was just wanting to do it right by replacing it as well since it houses the fuel filter within it in this case which is a good thing to replace when replacing the fuel injectors so it was more of a good measure I was taking and also it's due for replacement at 100,000 miles and my car is at 140,000 miles and my fuel pump also failed around 130,000 miles on my previous 4th gen v6 camaro. These were my reasons for replacing the fuel pump. I never suspected it to be the the problem, it does however appear the fuel injectors were a part of the problem however since the issue was not as bad after they were replaced and then nearly remedied entirely after putting the old OEM square coil pack on the misfire still occurring on cylinder 2 in this case and no longer consistently triggering a misfire on cylinder 6 like it was consistently before the fuel injectors were replaced. Also when it did misfire after the fuel injectors were replaced the misfire was hardly noticeable although the stabilitrack light and misfire code would come up on cylindar 2 until I replaced it with the original stock square coil pack. Another reason I suspected the fuel injectors was cause the car would misfire at traffic stops which is a symptom of failing or clogged fuel injectors, also a guy had mentioned in the youtube video I had posted that it was in his case the fuel injectors, also cause at that point I had changed and replaced all other components of the ignition system aside from the fuel injectors and also cause fuel injectors are only said to last up to 100,000 miles I'm sure they can last longer but are only guaranteed a maximum of 100,000 miles

To sum it up, its looking like it was related to the spark plugs chevy dealership gapped incorrectly and installed, the chevy dealership still leaving the old wires on the car despite me asking and paying for them to be replaced, my coil packs also getting old and not being able to handle the tune up that was performed afterwards, me buying cheap generic ebay round delphi coil packs instead of the original stock square OEM ones from a legit source, and the fuel injectors even though I've never ran anything but premium in the car the whole time I have had it, also possibly a difference between the 41-162 spark plugs that are said to be a replacement for the stock 41-110's that were factory and in the user manual since I found those and installed them properly myself. In my findings the fuel injectors were in fact related as part of the issue.

One good thing about changing these parts is the car is running much better now, it seems to have a lot more power then it did before and hopefully I am money ahead on all these parts that were said to be needed to be replaced at 100,000 miles anyways although this has really turned into a huge fiasco.

I still don't have my new correct OEM square coil packs yet so like I said we will see what happens after I put those on along with the correct wires. something else will probably go south or start happening as has been the common trend here. At least at this point I can put it back as is , as it's nearly 100% as is, just still have cheap ebay round delphi coils and wires on the car

Not sure it matters the square vs the round delphi coils both are said to be compatible although it originally had the square ones stock so I suppose it's best practice to put those on even though I couldn't find them at first which resulted in me buying the round ones to begin with as both are OEM. just like the stock spark plugs the 41-110's being a mystery to find and said to be discontinued I settled for the round Delphi coils cause the square ones are somewhat a mystery to find also. I did first look on ebay but what comes up are these generic wannabe square coil packs and the round ones I went with on ebay are supposedly ACdelco and share the correct part number on them and I settled for them with the cheaper price. Also good to avoid cheap ebay parts true I agree, you get what you pay for and this only added to the confusion of this process.

Another thing is its also stupid how ACDelco has made it such a tricky & mysterious process in finding parts for this very common and popular car however by discontinuing the 41-110's and changing the stock spark plugs to the 41-162's I've noticed they have also done this with there OEM stockoil filter for this car, although it seems in recent times they are bringing them back and or making them again as I was eventually able to find them recently the stock oil filter and spark plugs. perhaps ACDelco recently realized they need to make and provide these parts again. Local auto parts stores should have ACDelco OEM parts in stock but in my experience over the years finding them is like hunting down a unicorn. Usually any local parts store will have to order them most of the time if they can provide them adding to the confusion is all these cheap knock offs that seem to be sold in place of the OEM ACDelco parts, first thing on Amazon that comes up for me when looking for the square coil packs are some that almost look like them but they have no label on them but look identical. when you scroll way down however u can find the real ACDelco OEM ones for about $500 dollars for all 8 on Amazon

[Camarosmith]

ok so the correct square OEM coil packs arrived directly from GM I installed them along with the official OEM spark plug wires and the car started up with a misfire I turned it off and back on and no misfire, same thing happened when I first installed the cheap ebay round Delphi coil packs. idk if the ECM needs to adjust to the new coil packs or what at first but this seems to be a usual thing also upon changing them I've noticed.

There seems to be no misfire issues while driving the car anymore however this morning I started the car up in my garage and no misfire as it was a cold morning but what is still happening is after I back the car out of the garage after it first starts up if it doesn't misfire on the cold start is if I turn it off after starting it and backing it out only having it run for a minute or two, when I later go to start it back up to leave a few minutes after and the car usually has a misfire upon that second cold startup commonly. This issue seems to be consistent through this whole process.

At this point I have official direct from GM OEM brand new square coil packs, brand new official OEM legit spark plugs ACDelco 41-110's and the correct OEM ACDelco spark plug wires, all new fuel injectors, a new OEM fuel pump and fuel sending unit, and a brand new battery installed.

My thoughts at this point is it is some type of vacuum leak causing this I asked the shop to check for vacuum leaks and they said they did & didn't find any but I'm not sure that's the case.

I'm gonna need to take it to someone who can identify this cold start problem as I'm at a loss with it.

My thoughts are the Chevy Dealership did something to the car also.

[Joe.G]

Mis Fire could possibly from fuel leaking into the cylinder, I am still leaning towards a weak connection in the harness. If you don;t have the proper tools or knowledge to diagnose it properly with out throwing parts at it then you should bring it to a qualified tech.

[Camarosmith]

Originally Posted by Joe.G

Mis Fire could possibly from fuel leaking into the cylinder, I am still leaning towards a weak connection in the harness. If you don;t have the proper tools or knowledge to diagnose it properly with out throwing parts at it then you should bring it to a qualified tech.

Yeah it could be the wiring harness as well just being older and having some type of failure.


I'm just only having the occasional misfire on a cold start on cold days now it's back from cylinder 2 to cylinder 6 on my latest cold start misfires with the new square OEM coil packs on from GM directly. I notice it mostly or more common to be an issue when it's cold out or a cold day, even with the new correct directly from GM square coil packs installed with the new spark plug wires and the replacement of the fuel injectors along with the new fuel pump module as well a the new fuel sending unit and new battery

Well that was until I took the car on a 30 minute drive today and on my way back while driving on the freeway the fuel pressure sensor goes out on the car and I had to pull to the shoulder of the freeway and get my car towed home as I lost all power and could no longer start the vehicle. I have started to carry my code scanner with me since issues have now become so common and I had it and did a scan on the car and found that its showing the code P018B 1/1 Permanent - Fuel Pressure Sensor Performance

Another kind of funny thing that happened to the car is after I fueled up recently for the first time the car had been filled up again after the fuel sending unit was replace to fix my gas gauges that stopped working 3 days after the new fuel pump was installed is I filled the car up but it still showed it was at 3/4 a tank which was the level that it would have been detecting when I had the car back in to do service for repairing the non functional gas gauge. Anyways after I had about lost it at that point I drove home and on my way back the gas gauge corrected itself to show it was full, like the system had to take time to realize the difference between 3/4 a tank and a full tank of gas with the new fuel pump and fuel sending units installed. I'm glad that seemed to straighten itself out as I was about to take it back to them to get that right.

I am documenting the trail and tribulations of this long chain reaction of events that started with me just wanting to be proactive and do some preventative maintenance by having the Chevy dealership work on my car to replace the spark plugs and asked and paid for new spark plug wires to be installed but they left the old ones on and charged me for new ones anyways then wrote a check to refund me for the wires I paid for they never replaced and said they did.

Also since Chevy tried to hit a lick on me by insisting I pay up front only to present me with my car with the new spark plugs installed that took them 6 days and is now misfiring. I knew something was wrong immediately when the Chevy mechanic drove the car out to me misfiring and gets out and goes " Shhyeaaah! " and walks off. Then I look on dash to see the check engine light is now illuminated and wasn't prior to me driving it to them. I went ahead and told my friends at American Express about there fraudulent services and got a full refund for the fiasco they created here and didn't own up to, and then added insult to injury by lying to me and telling me the car was like that when I brought it to them instead of just owing up to the fact that the car is now misfiring after they replaced the spark plugs and coming at me straight with what was actually going on with the vehicle and I woulda took it from there with them and had them identify at least if not fix what was the cause of the now misfiring vehicle after they replaced the spark plugs on it. Chevy should have also been honest with be about how they never actually replaced my spark plug wires I paid them to replace.

If the car was like that before I brought it to them I damn sure would have know about it and asked them to address it, which should also be obvious to them with my track record with taking my car to this particular chevy dealership over past 6 years and having them repair it. I even took my 4th gen to them much longer before that a few times going back at least 10 years.

[Camarosmith]

Im about to get the car towed back to the shop tomorrow morning since it no longer starts at all due to this all a sudden while driving on the freeway 30 miles from home CEL error that came up

code P018B 1/1 Permanent - Fuel Pressure Sensor Performance

and see if the shop can determine and repair what the cause of the issue is.

If it is fact a failed fuel pressure sensor well that happens to be located on the fuel tank near the front top of it and will require the shop to have to for a third time in the last month or so drop the whole rear end of the car to replace. Hopefully it's just something on the fuel rail or somewhere else and an easy fix although I'm expecting it at this point to be the fuel pressure sensor on the top front of the fuel tank which will require them to drop the rear end and driveline and everything else on the vehicle to get in there a third time and replace it resulting in another huge bill and tons of there time and labor involved.

Stupid because of that I couldn't even limp the car home fuel pressure sensor goes out on this car it's bricked and completely inoperable which is also lame.

Replace one part and something else breaks. These are all the parts the break after you replace what I have replaced on this car at 140,000. We will see what else breaks next and how soon it will be. my transmission went out on my 4th gen v6 at 144k or 147k miles and I was gonna get it rebuilt and then I bought this one. This one is a manual however not an automatic like my v6 4th gen was. I kind of wish I woulda kept the 4th gen and got the transmission rebuilt on it also

[Joe.G]

Should be able to replace the sensor without dropping the tank.

[Camarosmith]

Ok so I got the car back from the shop after they said they had to replace the fuel pressure sensor on the tank and also replaced a fuel pressure sensor that was on the side of the tank on one of the fuel lines to avoid further issues.

I get in my car to drive home and had about 1/8th a tank of gas on the gauge.

I am right at the last intersection before my home and the check engine light comes on and I had to pull over to the shoulder of the road.

I connect my code scanner and sure enough I get the same code P018B 1/1 Permanent - Fuel Pressure Sensor Performance

I call the shop up I just left and let them know. Guy tells me that the car ran out of gas and they had to put a gallon in it themselves and were able to start the car again.

I can see my gas gauge was raised slightly above empty still showing almost 1/8th a tank of gas with no low gas notification to appear like I'm used to seeing

So the guy from the shop said to go get some gas and put it in the car and try to start it again so I went and did that and was able to start it and drive it home the rest of the way.

This tells me that there probably was no need to change the fuel pressure sensor on the tank as well as the one they said they changed on the fuel line as a good measure in the first place, although when I asked them they said the fuel pressure sensor code was still present after they added gas and were able to then start the car.

So what's happening is when the car is almost on empty on the gas gauge at say around 1/8th a tank where the car should be showing the low gas notification.

The car at that point is just out of gas entirely without any warning of being low on fuel

And then it just shuts off and gives the P018B fuel pressure sensor code.

The P018B code went away when I put more gas in the car

I let the guy from the shop know all of this and I'm going to take it back to them to fix it as I have already paid for these things to be resolved and they were not prior issues until they changed the fuel pump and then later the fuel sending unit on the vehicle.

I need to car to give me a low fuel warning before it just shuts off, not to shut off and run out of gas showing nearly 1/8th a tank of gas on the gas gauge.

[Joe.G]

Sotge shop gave it back to you knowing the gauge isn't reading correct? Isn't displaying low fuel warning? And that the gauge is not reading correct and you have a Gallon or less left? Sounds like a good place to go. Now I don't know if it will or not on your car but when I replaced a fuel pump o a Benz I had a issu with gauge reading wrong but after I filled the tank it adjusted and worked fine ( yes it was clocked right in the tank ).

[Camarosmith]

I took it back to the shop and they replaced the pump and the sending unit again they said and got the car back to me and the gauge worked correctly.

My theory on this is they may have tried to used the old part of the old fuel pump with replacing the pump module alone and reusing the old arm and sensor unit that clips into the pump module and or they damaged the new unit when it was installed or it was in fact just a faulty new unit

They fixed the gas gauges and I am getting the low fuel warning again. When got it back from the shop. The only thing is, it was low on gas so I went to gas up right after and then gas was leaking from under the car while fueling up. I took it back to them to fix the gas leak upon fueling up and it looked like it was leaking off one of the lines connecting to the top of the tank as I watched it during the fuel pump process so maybe the forgot a clamp on one of the lines or something.

I just took it back to them today to fix the gas leak and am awaiting return of the vehicle

I still have the issue of the car misfiring upon startup on cold days but no longer have with misfires while driving issues while driving since the fuel injectors and pump and sending unit and fuel pressure sensors were replaced. I believe this is mainly due to the replacement of the fuel injectors.

My theory on the cold start misfire is my car needs an actual tune as I noticed the new spark plugs I installed looked pretty bad fairly quickly after having been recently installed. I'm going to take it to a reputable shop that has experience in tuning cars and have them tune it and or diagnose it but I know it needs a tune as the new spark plugs should look good if it is properly tuned

[Joe.G]

Seems like you have spent a ton of money and caused yourself a lot of headaches for no reason. Hopefully you get it sorted out.

[Aqua Blue RS/SS]

You don’t need a tune unless it’s got stuff like a cam, headers, boost, etc.