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Ghost Misfire

6K views 33 replies 9 participants last post by  kgschlosser 
#1 ·
What I got: It's an 07 Solstice gxp with 81k miles on it. It is mostly stock with a "factory-authorized GMPP Stage 2 tune" when purchased.

I fixed some Intake Air Temperature sensor issues that plagued the car when I bought it. I replaced the plugs and coils. Packed the coil connectors with dialectic grease.

The problem: What started me down the path of fixing the aftermarket intake sensors was the relentless misfire codes. Once fixed all the codes disappeared, for the most part. Now when it rains or is moist out. I get a misfire in cylinder 1. Always cylinder 1 and it comes and goes. The car runs like sh!t till it gets to about 90 degree coolant temp then runs great afterwards. I'm at my wits end to figure out what is wrong with the car. I thought, at first, that it was cold related but it does it when it's warm out as well. This thing is a cold blooded b!tch too. It will not start below 30 degrees. When it's been dry out for a few days the code goes away on it's own.

I'm not familiar with the 2.0l motor so I'm at a lose. please help?
 
#2 ·
You are missing the weatherstripping that runs along the edge of the wiper cowl. Or it is no good and should be replaced.

I am also going to say that you do not have the plastic cover on the engine. what is happening is water is running down the windshield runs down the cowl and drips onto the top of the valve cover right into that well where the coils are. The water has no place to go except to the front of the engine if the car is pointed down hill. The water gets to the front of the valve cover. where it ponds up eventually getting into the first spark plug tube. when the water gets deep enough inside of the tube the spark is going to travel through the water to the head instead of to the plug.

You can verify this by pulling the coil pack from the cylinder closest to the front of the engine and looking in the tube. Take paper towel and fold it up so you can get it down into the tube to soak the water up. DO NOT pull the spark plug if there is water in there!!!
 
#4 ·
You are missing the weatherstripping that runs along the edge of the wiper cowl. Or it is no good and should be replaced.

I am also going to say that you do not have the plastic cover on the engine. what is happening is water is running down the windshield runs down the cowl and drips onto the top of the valve cover right into that well where the coils are. The water has no place to go except to the front of the engine if the car is pointed down hill. The water gets to the front of the valve cover. where it ponds up eventually getting into the first spark plug tube. when the water gets deep enough inside of the tube the spark is going to travel through the water to the head instead of to the plug.

You can verify this by pulling the coil pack from the cylinder closest to the front of the engine and looking in the tube. Take paper towel and fold it up so you can get it down into the tube to soak the water up. DO NOT pull the spark plug if there is water in there!!!
I'll have to look into the weather stripping. The cowl thing is there but it is missing all the covers under the hood, even the turbo heat shielding. I thought this might have something to do with it. Thank you for giving me a direction to start from. I had planed to replace most of what is missing from the previous owner. Will give update later.

As for letting it warm up when it's cold. I usually wait till it gets to 100 degree water temp then take off. Seems to work fine after that. I actually considered de-tuning the car and returning it to factory. Because, replacing the "upgraded" sensors was such a pain in the a$$. Summit had them on back order for a month, then, decided we don't make those any more. Amazon had them. Waited a month, then, they decided that they were lost in the mail. I found some place based in Florida that promised to get them for me... from Europe, that took a month to sail to the states. 3 months just to diagnose that it was the sensors in the first place. I was so upset. Thankfully they actually solved everything accept this moister issue. But, with your help hopefully I can remedy that as well.
 
#3 ·
The Solstice does not like the cold, I don't know of any high performance vehicles that really do. Plus you also have a more aggressive tune which makes it worse. You shouldn't be operating the vehicle without letting it sit and idle for at least 5 minutes when it is below freezing. This is because of the high idle condition spooling the turbo some and there not being any vacuum for the brakes. GM has devised a way to get the brakes to work somewhat using either using an electric vacuum pump or by using the ABS. either way the brakes feel funky when either of those systems are active. Let the car warm up.
 
#5 ·
Better than returning tune to factory - replace the sensors with stock ones rather than the ones the GMPP tune specifies, and buy a Trifecta basic tune, which runs with the stock sensors. More power no problems. Hopefully the stock sensors were used on enough cars that they will be available indefinitely.
 
#6 ·
ah... so you have a GMPP do you ?. ...

you need to check if your wiring was soldered ( not crimped ) !!!

read this thread - it has photos -> GMPP and soldering
 
#7 ·
The upgraded sensors you can get from Performance Auto Werks. They will need to be modified slightly by pressing the sleeve out of the hole on the sensor. It is easily done with a socket a bolt and a hammer. Other then that it's a snap. As was already mentioned is the issues that can come up because of the "butt" connectors used if the GMPP tune was done on the vehicle.

I am personally not a fan of soldering any wires in a vehicle, especially on a sensor or data wires. Solder does have resistance to it and can muck things up by skewing a sensor reading slightly or mess with a data system and crimp connectors also have resistance to them as well. It is better to twist the wires together and use rubber tape to cover the connection. Rubber tape will not allow moisture in and can be gotten at any hardware store.

There is a specific way the wire should get twisted together, when done this specific way if the wire gets pulled on at all it is not going to come undone, It will tighten. Here is a video on the proper way to twist the wires together.



you need to check the wiring at the MAP sensor and also the intake pressure sensor on the pipe going to the throttle body (next to the hose) if you have any kind of a crimp connector on the wires you will need to remove it and either solder or twist them together as shown in the video.
 
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#8 ·
The GMPP Turbo upgrade MAP sensors are Bosch (at least mine are) and are held down by a single bolt, not 2 as were the original units. I'll get to why this can be an issue. I have fixed cold start and occasional abnormal running problems in my own 2009 GXP. Remove the MAPs and the EVAP solenoid from the intake manifold and check the O-rings for deterioration caused by time/heat/cold conditions. My first fix was too simply sparingly coat the O-rings with silicone grease and re-install the units. The car once again ran just fine for a while - weeks, a couple of months, etc. then the problem returned and I again did the grease thing and the problem was again solved for a time, etc. I then came up with using a meager amount of Teflon tape above the O-ring against the under side of each unit to supplement sealing and again the problem went away for a longer period of time. I was not really happy with the fix up to now. So, I have now utilized a full compressible gasket under the base of each of the units along with silicone grease as before and I believe the problem is now, more or less, permanently alleviated. However, to assure a good seal of the MAPs I made a couple of clamps that hold them down evenly by the once missing bolt. The car now starts more quickly, idles smoothly, and idles down beautifully. Performance wise, the car has almost instantaneous boost jumping to 20 PSI at the flooring of the gas pedal - it seriously is a different operating car. In COMPETION mode it is a different car!
Regardless of how your car runs now, it will run better if you do what I've suggested and eliminate at least one possible problem that may be complicating diagnosing any other problem you may have. If the MAP and EVAP solenoid O-rings have never been looked at they should be and do as I've recommended. You may well be very pleasantly surprised and it costs practically nothing but some time. As to the electrical connections, I was not a fan of cutting and/or splicing and soldering my connectors for the new sensors. I used tapping connectors and retained my original plug ends, just in case. Have never had a problem and this was done more than 4 years ago. I did tape over the connections. I've used this method in other cars as well with the same good results.
Let me know if you need more specifics. I'll be glad to help.
grandpop07
 
#9 ·
I did run into this issue as well. The sensors are Bosch and they are just one size too small for the O-ring to seal. I did this one trick that an old mechanic taught me when I was young. You take electrical tape and wrap it around the O-ring seat. Pull it very tight so that there is an indention were the grove is. Put on one layer of tape at a time until you get a satisfactory seal and your done. If you have to put on so many layers that the grove disappears completely then you need to do something else. It works great and no issues since.

The upgraded sensors you can get from Performance Auto Werks. They will need to be modified slightly by pressing the sleeve out of the hole on the sensor. It is easily done with a socket a bolt and a hammer. Other then that it's a snap. As was already mentioned is the issues that can come up because of the "butt" connectors used if the GMPP tune was done on the vehicle.

I am personally not a fan of soldering any wires in a vehicle, especially on a sensor or data wires. Solder does have resistance to it and can muck things up by skewing a sensor reading slightly or mess with a data system and crimp connectors also have resistance to them as well. It is better to twist the wires together and use rubber tape to cover the connection. Rubber tape will not allow moisture in and can be gotten at any hardware store.

There is a specific way the wire should get twisted together, when done this specific way if the wire gets pulled on at all it is not going to come undone, It will tighten. Here is a video on the proper way to twist the wires together.



you need to check the wiring at the MAP sensor and also the intake pressure sensor on the pipe going to the throttle body (next to the hose) if you have any kind of a crimp connector on the wires you will need to remove it and either solder or twist them together as shown in the video.
I'll have to try that method next time I do some wiring. I also thought this may have contributed to my initial issues with the car. I think they had someone do this tune up and then couldn't figure out why it wouldn't run right. Probably why they sold it so cheep. I did re-wire the sensors when I got the replacements. I twisted them together as best I could and used those solder butt connectors that also serve to weather proof them as well. Every thing worked great afterwards.

Update: I scrutinized the weather seals on the cowl panel and they seem to be fine. I poured several gallons of water in various places and didn't see any leaks around the vale cover or engine. I think I'll try and find a replacement engine cover and see if that works. May take a while to get one and a while yet to see if that fixies the problem. If it weren't for this intermittent misfire the car would be perfect.
 
#11 ·
memory tells me that the O rings are an odd size, but I might be mistaken and in any case you should be able to source just about any size with a bit of hunting.. I have a vague recollection of someone having problems getting new ones way back when the cars were new, though.
 
#12 · (Edited)
rut rooo. I believe I know what your issue is.. You said you bought new pressure sensors. The ones you bought do they have one bolt hole or 2? Because if you took off ones that had 1 bolt hole and put ones on that had 2 bolt holes you put the wrong ones on. same goes vice versa. From what it sounds is that you need one with a single bolt hole. You are also going to need different o-rings for them and you will have to press out the spacer that is in the bolt hole on the new sensors.


Here are the sensors that have the single mount hole.

the above comes with the proper o-rings and also pigtail harnesses, tho the pigtails would be useless for you.

I know you said there was no apparent leak at the cowl but that is also while the car is standing still and not moving down the road. These cars do have quite a bit of flex to them and I wouldn't be surprised if it only leaked when the car was moving. The sure fire way to tell is to pill the coil pack on the #1 cylinder when the misfire code comes up. and roll up a piece of paper towel and stick it all the way down to the bottom of the hole next to the plug. If there is water down there the paper towel will come out wet.

I find it suspect that you are only having the problem on cylinder 1 and only when it is raining. and because of the design of the valve cover and the position and shape of the cowl this seems like the problem. Do you park the vehicle with the noise pointed down hill? If you are unsure just look at your trunk after it rains, do you have a swimming pool between the 2 humps? if the answer is Yes then turn the car around the other direction when you park it, the water sitting against the top is going to rot it. And this is also a good test next time it rains, see if you have the problem. If you don't then you know that water is entering the engine bay and getting into something.

There is a TSB about water coming in when the engine cover is on and the wate runs down the back of the block and onto the bell housing where it manages to find it's way into the bell housing and onto the clutch. During the winter the clutch ends up frozen and is not able to move.
 
#13 ·
@wspohn

I picked up an o-ring assortment pack at the local auto parts store for 8 bucks and it had the proper size o-rings in it. It actually had the right o-ring for the purge valve and also for the 3 bar sensors. Maybe I got lucky and found the right assortment pack.
 
#14 ·
I had this same issue when I first got mine. Like someone throwing an anchor out the back when you get on it.... My advice, have it retuned. Whomever tuned it didn't know what they were doing. Probably the same person that tuned mine. I have an idea as to who tuned mine, but I'm not going to say because I can't prove it 100%. Get a Trifecta tune from DDM and be done. It can be zero out now with mine (and I'm dyno tuned) and I can start it up and go. Of course I don't push when it's that cold, and mine is now a garage queen and goes away in October, but I can tell you, I can mat it a minute after starting it and it doesn't fall on it's face anymore.
 
#15 ·
@ kgschlosser Those are the exact sensors I have. The factory ones use two bolts. Again, I'm pretty much stuck with the single bolt aftermarket sensors for now. They are brand new with new O-rings. They work well and my electrical tape mod is holding up great. I missed the part in my tutorial were you reinstall the O-ring over top the tape were the grove is. The tape literally increases the diameter of the part allowing the O-ring to seal properly. The tape is held firmly in place by mechanical grip as well as adhesive. I would say it's like putting a bead roll on charge piping to keep the clamps in place. No slippage.

The car sits on a leveled out parking pad. Water does pool a little, but it's more center of the trunk and not against the soft top. I also put a ceramic coating on the car after I bought it to help it shed water as well as keep it cleaner for longer. I did check for moister in all of the spark plug tubes and didn't find any. However, it hasn't rain in a day or two so I may not have caught it in time. I have ordered the DDM works valve cover... cover, but, I'm not convinced it'll make a difference on it's own. If you look at the coil pack cut outs, they are on the side that the motor leans to(downhill side). I am going to try and put some weather striping around those cut outs to divert any water away from the openings. It'll take a bit to receive the cover so I'll have to update you later on this. I'll take pictures of my results.

@ The_Ghost
I'm not sure who tuned mine. I've only had it for a year and a half. I immediately undid most of the previous owners mods. It's mostly back to stock config except this GMPP tune. I ripped all the 5$ neon lights off as quick as I could. The under glow and interior lights they installed never turned of unless you turned off the car. You could've seen my car from space at night. I replaced the 1$ radio with a 300$ Kenwood with back up camera and everything. Now I just need to do all the 80K maintenance things this year. Pretty much goin to replace the whole front of the motor accept the alternator.

This Trifecta tune sounds promising I'll have to look into it.
 

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#16 ·
It's only during start up when the car has sat for a while in the rain or heavy fog, i,e 8-10 hours. The idle fluctuates up and down about 500-600 rpm for a while. Then about 90degrees it levels out and runs fine after that. If I take off sooner than that, it spits and sputters till it hits temp and then runs like a top. I don't know if this car has any kind of choke circuit or sensors that effect the cold start of the car. After I fixed my aftermarket intake sensors, the only code I get is p0101(I think), which comes out to misfire in cylinder 1. But it's sporadic and seems to return when it's cold or there is heavy moister in the air and disappears a few dry days later all on it's own.
 
#18 ·
What is that T-spliter coming off of your already t-split BOV?
 
#20 ·
Does your check engine light flash at all?

Move the coil pack on cylinder 1 to cylinder 2 and cylinder 2 to cylinder 1. then clear the codes. see if the misfire follows the coil pack. You could have a faulty coil pack, I have seen them brand new out of the box and be bad.

The only other thing I can think that might be an issue is compression. You would have to get a compression tester and check what each cylinder has for compression. It's either that or it's a clogged fuel injector.
 
#21 ·
Does your check engine light flash at all?
The only other thing I can think that might be an issue is compression. You would have to get a compression tester and check what each cylinder has for compression.
Dear god I hope there isn't anything wrong with the compression. Owned the car for 2k miles. It better not need a rebuild already. If so I'll send the motor off to DDM Works. They seem to have a really good package. As for the check engine light, it's solid. No flashing.

I'll have to try swaping the coils. Didn't think to try that.
 
#22 ·
Washed my engine compartment the other day, just the compartment being carful not to force water into anything. The only engine part to get pressure washed was the back around the oil filter. No water got under the engine cover. When I left the car wash the engine was running perfect, when I stepped on it, it felt like an anchor was thrown out. Tried it a second time and same result. I disconnected all the electrical connectors and sprayed them with electrical cleaner and dielectric greased the MAP sensors. I detailed the entire car and took it out yesterday, ran fine. My guess was the MAP sensor connectors.
 
#23 ·
you are getting the P0301 code correct? The while check engine light flashing thing is if the engine misfire is severe. Modern engines always misfire, this is because the engine management is written to push the limit on timing to keep the power up and also provide the best fuel economy. There is a threshold between allowed number of misfires and when the ECM is going to tell you that there is an excessive number of the, and also when there are so many that it can be engine damaging. You are at step 2 of 3. My suggestion is going to be to drive it, get to step 3, hopefully by that time whatever is causing the misfire is either going to show it's self or another symptom is going to show up. You can start throwing parts at it if you want, doing that can get expensive. If you have access to a mechanic that actually knows these vehicles and knows how to diagnose you can go that route as well.

There fact that it is happening only on the one cylinder and only when it is "damp" out make me think it is an electrical issue. and this electrical problem would be with either the coil or with the injector. Because you have not done anything with the injectors I am leaning towards an issue with the cylinder 1 coil pack or the wiring going to it. Swap the coils around and see if the problem follows the coil pack. if it does then you know that is where the issue is. if it doesn't then you will have to examine the splice pack for the grounds on the coils there could be an issue there.

Run a couple if tanks of gas through it with fuel injector cleaner additive in each tank, it can't hurt. Better yet... put a bottle of "BOOSTane" in your tank. Lets see if the misfire is pre-detonation. If it is then the BOOSTane will make the problem go away. and if it is not pre-det related it will continue. I doubt this is the issue but still worth eliminating as a possibility.

The only thing that would be causing it that is isolated to only a single cylinder and only when it's raining or "damp" is going to be the coil pack. If it was an electrical issue with an injector the ECM would throw a code specific to the injector. if it was a clogged injector it wouldn't matter if it was damp or not. the only system that is not specifically monitored for failure are the coils and the wiring going to the coils. Check the pins on the clip going to cylinder 1, make sure they are pushed in all the way. I can post some photos of how to unpin the clip so you can inspect the individual pins for "fretting corrosion", this can happen on our cars.

Other then that there is nothing much I can do without me diagnosing the car directly. I wish I can tell you do replace this part of fix this wire and your problem would be solved. Unfortunately you have one of those issues that is going to be a royal pain to track down. The cause is going to show up eventually you may have to ignore the p0301 code until that happens. You will want to scan the car every few days to make sure that is the only DTC that is set.
 
#24 ·
Dear god, I hope it doesn't have a compression issue. Had the car for 2k miles and it better not need a rebuild already. That and it's intermittent. A compression issue would be a constant misfire. I would think anyways.

The light is solid and doesn't blink. I'll have to try moving the coil pack around. See if that's it.
 
#25 ·
@kgschlosser I'll give all this a try. I'm kind of waiting for another shoe to drop as well. I really would like another (small) symptom to narrow down the possibilities. I do remember checking the pins in the connectors when I replaced the coils. I probably should check again, because I read somewhere that someone had an issue were one of the wires backed out of the connecter. I do put in 91 octane. Mainly because I wanted to, then found out later that the turbo motors pretty much require it. It has been a bit since last I put in some injector cleaner.
 
#26 ·
it's the damp weather thing that is leading me to think it is a problem with an electrical component.

Have you tried moving the coils around to see if the problem follows the coil?
 
#27 ·
Well, I'll put my 2 cents in here again. Read my post again re. flat gaskets (above). This fix will fix it and you'll likely never have to replace them. The O-ring becomes superfluous, other than essentially centering the MAP in the hole. However, you will need to make a couple of hold-down brackets as I did to properly put even pressure on the single bolt Bosch MAPs. Don't forget the EVAP (with single bolt hold-down) unit because you will have pressure bypassing that O-ring as well. The silicone grease migrates away from the O-rings and they leak by. If these O-rings have never been changed they should be, but you will eventually begin to have the bypass problem again. I won't. My GXP has never run better since I've had it for over 4 years. The thickness of the gaskets under the MAPs is not extremely critical, but it is critical under the EVAP solenoid. If anyone would like to do my fix I will be glad to give you the exact thickness of the gasket(s) under each unit . Not only that, I'll send you the gasket material. I have a huge roll of it. I'll even cut out the gaskets for you. Have fun and enjoy the cars while you can still buy the gas for them!
grandpop07
 
#28 ·
Update #1: I may have figured out my issue. To be determined of course. I bought all Blue Streak coils. They have a puny ground strap soldered to a washer were the bolt goes through. I did not know this before hand and admittedly tightened those bolts a little too much. As I kept taking the #1 coil off, I eventually broke the metal washer from the ground strap at some point. I replaced the #1 coil and used dielectric grease to lube the washer so it won't break again while tightening. I'm not calling this fixed though. I've been fixing this misfire for a year now. and each time I "fix" it, it comes back.

update #2: I received my DDM works stainless steel valley cover. It looks ok. It's a little rough around the edges. I'm going to install it straight up with no weather stripping to seal the coils, but, only for the moment. I want to see if that ground strap is the problem and also see if just having the cover on the motor makes a difference.

I think that these 2 fixes may solve it but I'm not holding my breath either. Should get a big storm this week so updates to come.
 

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#30 ·
The moisture would only occur if the seal on the wiper cowl has been compromised in some way. If no water gets past the cowl seal when doing a garden hose test then it should be OK.
The coil ground would be an issue. This is the exact reason why many shops that work on the Kappa's state only GM coil packs. I personally put in NGK coil packs, the construction is identical to the OE ones and doesn't have that washer with the ground wire. You my run into an issue using dielectric grease. it is not conductive. the only thing dielectric grease does is it keeps air out of the connection so no oxidation can form.
 
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