[Alobos05]

Yes I have a MBRP Catless. yes i Checked the gap and tonight I even changed out the 4 plug with a brand new one. It started well with no misfires on the AP but I will see tomorrow morning. The plugs have been used for no more the 2k miles. Yeah the misfire is only on cylinder 4 according to the AP and about 2 weeks ago it began.

 

[gatornek]

Yes I have a MBRP Catless. yes i Checked the gap and tonight I even changed out the 4 plug with a brand new one. It started well with no misfires on the AP but I will see tomorrow morning. The plugs have been used for no more the 2k miles. Yeah the misfire is only on cylinder 4 according to the AP and about 2 weeks ago it began.

Good morning. The plugs should be fine, then. You earlier indicated that your reservoir tank was "lowering as usual" or similar to that wording without me going back and checking. In all honesty, the coolant system is a closed loop, and evaporation should have no effect on it. If you're missing any coolant after a some time, it may be possible that you have a small fissure in the gasket around cylinder 4. That might also be a good explanation on why it only happens on morning cold starts, when your engine is a stiff as possible, but then goes away after some combustion warms it up some, and allows the head to rest better in place. I don't wanna alarm you, as this is only conjecture, but you may wanna do a compression test if you're able.

If your coolant is absolutely NOT lowering, then yeeeesh, I'm not sure. The only thing really left would be to try swapping the coils from one cylinder to another and seeing if the 'misfire' follows it.

More specifically to the previous question, was there any change made to the car two weeks ago, when this began? AP install? A new tune?

 

[Alobos05]

Good morning. The plugs should be fine, then. You earlier indicated that your reservoir tank was "lowering as usual" or similar to that wording without me going back and checking. In all honesty, the coolant system is a closed loop, and evaporation should have no effect on it. If you're missing any coolant after a some time, it may be possible that you have a small fissure in the gasket around cylinder 4. That might also be a good explanation on why it only happens on morning cold starts, when your engine is a stiff as possible, but then goes away after some combustion warms it up some, and allows the head to rest better in place. I don't wanna alarm you, as this is only conjecture, but you may wanna do a compression test if you're able.

If your coolant is absolutely NOT lowering, then yeeeesh, I'm not sure. The only thing really left would be to try swapping the coils from one cylinder to another and seeing if the 'misfire' follows it.

More specifically to the previous question, was there any change made to the car two weeks ago, when this began? AP install? A new tune?

in all honesty I have never really seen the level of the coolant before this happened but as of right now it has been sitting about a hair above minimum but that hasnt changed since this happened. nothing has changed in the car for over 2-3 months or more since I got my tune. I already swapped the coils with cylinder 1 and it did not follow it.

 

[gatornek]

in all honesty I have never really seen the level of the coolant before this happened but as of right now it has been sitting about a hair above minimum but that hasnt changed since this happened. nothing has changed in the car for over 2-3 months or more since I got my tune. I already swapped the coils with cylinder 1 and it did not follow it.

I mean, honestly, the only other thing you can do without doing a compression test, is replace the Low side fuel pressure sensor and the evap valve. But, a)I think Adam has you do those things before he tunes you if I'm not mistaken and b)they are, more than likely, not the culprit.

If I were you, and the car is under 60K, I'd revert back to stock tune, uninstall the AP, and take it into a service center at a dealership. With some magical luck, they might take it under warranty. Its worth a shot; and at the very least, they could offer you a price quote on a compression test. If you want to call the garage I mentioned earlier to get a comparison quote, let me know and I will call them ahead of time so they know that I referred you and will hopefully give you their best pricing. I'm also fairly sure the DIY garage i go to has compression test tools, but its a bit of a hike for you since its all the way in North Miami.

 

[Alobos05]

yeah adam had me change those two out. Unfortunately I am just over 60k im at 61K. I will actually be doing a compression test this weekend and ill see how that turns out. I have an appt with SS Performance on the 21st so they can take a look at it but I just want to hit everything before they try and redo everything that I coudlve tried. With the car being tuned and FBO I tried looking up places that seemed like the could handle that and these guys seem to be the only ones that seem reputable. I just find it really weird that I am having no symptoms of a blown gasket and the car being able to idle just fine. I decided to give the car a break today so tomorrow I will take it out for a spin with the brnd new spark plug in the 4 cylinder and see how that goes.

 

[Bigredky]

I’ll take a look at messaging Parker Performance. It’s just a really weird situation with it being so random. It even idles just fine. No leaks or smoke or milky oil. I’m thinking maybe carbon build up in the valves?

Did you get it figured out ? The plugs may not be pregapped. I think they suppose be around .23 range . I get my plugs from parkers and they gap them so your needs . Either running 93 , meth ..etc

 

[Alobos05]

I get my plugs from tune plus and they are pre gapped.
I actually replaced the 4 cylinder with a new one last night and just about an hour ago I started the car and it started just fine to stuttering or anything. But then I got two new codes. One for cylinder 2 and I forgot the code number but it’s for random misfire. Along with the 4 cylinder misfire and the misfire on first 1000. Only god knows what’s wrong with my car now lol

 

[jdsfly]

What spark plugs were you using, when this problem started, and what are you using now? Tune+ has changed plug manufacturers from time to time. Also, Tune+ sells gapped and ungapped plugs. Did you check the gap yourself? They should be .028". Always check them yourself. Just be careful, as the center electrode is fragil. Are you using the stock heat range plug or one colder? Does no. 4 spark plug look or smell any different than the other 3? It would be best to check the plugs right after a cold start event, when the misfire event occurs. Don't wait for it to stop misfiring. When you have misfire, shut it off right away, and pull the plug. Burning antifreeze has a very distinct smell that you may notice on the spark plug or at the exhaust exit. It's possible to have a damaged head gasket that leaks a small amount of coolant into the cylinder, when it cools down, and it burns out of the cylinder during cold start and warm up, then seals back up. Burning coolant would show as white smoke, with a sharp acrid odor. If it's a head gasket, it will get worse with time. Do you have a 93 octane or E-30 tune?
Carbon buildup on the intake valves is not common on our engine, even without a catch can, but the most common symptom of it is cold start and cold driveability. What oil do you use? A full synthetic, with an API rating of SN+ would be best. If you want to look at the valves, the intake manifold comes off pretty quick and easy. Tune+ made a YouTube video on how to remove it, in conjunction with installing a catch can.
Bad fuel injector spray pattern can also cause cold start misfires, if you wanted to swap that. I wouldn't think that would be a problem at 60k miles, unless you were using some crap gas. Do you use Top Tier gas?
Answer my questions, and keep us posted, please.

 

[RichBrew]

My money is on the head gasket. The sputtering at startup is coolant in the cylinder. Let is sit for a day, pull the spark plug, get a flashlight and a stepladder, and climb up i top of the motor to look in. I’ll bet you see liquid. Tape a QTip to a straw or something to get a sample of the liquid to see what it is. I had identical symptoms (but only after skittle isle for 2 days) and mine came out orange...coolant.

 

[Alobos05]

My money is on the head gasket. The sputtering at startup is coolant in the cylinder. Let is sit for a day, pull the spark plug, get a flashlight and a stepladder, and climb up i top of the motor to look in. I’ll bet you see liquid. Tape a QTip to a straw or something to get a sample of the liquid to see what it is. I had identical symptoms (but only after skittle isle for 2 days) and mine came out orange...coolant.

I will be taking a look tomorrow on that that way I can let the car sit. You had to replace your gasket?

 

[Alobos05]

What spark plugs were you using, when this problem started, and what are you using now? Tune+ has changed plug manufacturers from time to time. Also, Tune+ sells gapped and ungapped plugs. Did you check the gap yourself? They should be .028". Always check them yourself. Just be careful, as the center electrode is fragil. Are you using the stock heat range plug or one colder? Does no. 4 spark plug look or smell any different than the other 3? It would be best to check the plugs right after a cold start event, when the misfire event occurs. Don't wait for it to stop misfiring. When you have misfire, shut it off right away, and pull the plug. Burning antifreeze has a very distinct smell that you may notice on the spark plug or at the exhaust exit. It's possible to have a damaged head gasket that leaks a small amount of coolant into the cylinder, when it cools down, and it burns out of the cylinder during cold start and warm up, then seals back up. Burning coolant would show as white smoke, with a sharp acrid odor. If it's a head gasket, it will get worse with time. Do you have a 93 octane or E-30 tune?
Carbon buildup on the intake valves is not common on our engine, even without a catch can, but the most common symptom of it is cold start and cold driveability. What oil do you use? A full synthetic, with an API rating of SN+ would be best. If you want to look at the valves, the intake manifold comes off pretty quick and easy. Tune+ made a YouTube video on how to remove it, in conjunction with installing a catch can.
Bad fuel injector spray pattern can also cause cold start misfires, if you wanted to swap that. I wouldn't think that would be a problem at 60k miles, unless you were using some crap gas. Do you use Top Tier gas?
Answer my questions, and keep us posted, please.

I am using the NGK plugs pre-gapped sold by Tune+. When I pulled the plug it was a little bit more worn and black than the others but not by too much to cause alarm. It did smell different more of a burnt smell. it does smoke on a cold start but nothing apart from the usual morning starts as you can see in the video above. i have it tuned for 93. My last oil change was with Pennzoil full syn. as far as gas my last fill up was with 93 from Chevron- but i did recently move and I had to put gas on a Raceway station and that is literally when it started happneing the next morning. I dont want to put too much though into the gas as ive never had a batch fill up before but ive ran with the new gas about 30 miles so far and it has only stuttered once. I just dont think it would be the gas but I cant knock it out. Tomorrow is my day off and I will be doing a compression test and ill post the results here.
Does anyone know what the pressure should be for the test? I read somewhere else it shoud be around 160-170. Just want to make sure.

 

[Alobos05]

I have done compression tests before but never on a push to start car. Is the process still the same. Obviously remove all boots and plugs but as far as cranking, Im guessing I just hold brake and push the button once till it times out? I saw one video of a GT350 owner removing some fuses but then read on other forums that it should be the same. Anyone done them before on push to start?

 

[jdsfly]

I am using the NGK plugs pre-gapped sold by Tune+. When I pulled the plug it was a little bit more worn and black than the others but not by too much to cause alarm. It did smell different more of a burnt smell. it does smoke on a cold start but nothing apart from the usual morning starts as you can see in the video above. i have it tuned for 93. My last oil change was with Pennzoil full syn. as far as gas my last fill up was with 93 from Chevron- but i did recently move and I had to put gas on a Raceway station and that is literally when it started happneing the next morning. I dont want to put too much though into the gas as ive never had a batch fill up before but ive ran with the new gas about 30 miles so far and it has only stuttered once. I just dont think it would be the gas but I cant knock it out. Tomorrow is my day off and I will be doing a compression test and ill post the results here.
Does anyone know what the pressure should be for the test? I read somewhere else it shoud be around 160-170. Just want to make sure.

I liked what @RichBrew suggested about checking the head gasket, but since your problem is intermittent, you may not see any coolant in the cylinder, if that's the problem. I asked if you had a 93 octane or E-30 tune, because an E-30 tune would be more likely to blow a head gasket. I asked if you were using Top Tier gas, because that would likely keep your fuel injectors cleaner. I asked if you were using a full synthetic API SN+ oil, because that would likely keep your intake valves cleaner. Have you checked the spark plug gaps yourself? You want the gap at .028".

 

[Alobos05]

Yes the gapping is at .28. I honestly am at a loss for what it could be until I get a chance to check the compression

 

[jdsfly]

Do what I or RichBrew suggested, regarding the head gasket. Normally a compression test would be done with a warm engine, but in your case, since your issue is when the engine is cold, I would check it with a cold engine, and see if all 4 cylinders are about the same. Also, look in cylinder no. 4 for coolant, after you test it's compression.
Personally I wouldn't use a colder heat range spark plug, on a 93 octane tune, unless I was road racing the car, or the plugs didn't look good. You could try putting the stock heat range motorcraft plug back in.

 

[Alobos05]

So I let the car sit a whole day and just now I removed the spark plug and didn’t see any coolant residue. Also when I did the cold start it started perfectly fine. That spark plug has been running for about 10-15 miles

 

[Boosted5862]

So I let the car sit a whole day and just now I removed the spark plug and didn’t see any coolant residue. Also when I did the cold start it started perfectly fine. That spark plug has been running for about 10-15 miles

Hey man how’s it going? I had a similar problem as you and tried everything here to no avail. Then I decided to upgrade the head gasket and switch to arp head studs to see if that would help. Well, when we took off the head there was a deformation by cylinder 1 which is the cylinder I was getting the misfire on just like you with the number 4. Had to send it to a machine shop to fix it. I know that’s a big jump from the do it yourself quick fixes and a lot of money but it’s better than paying for a new engine. Good luck to you and I hope you figure things out brother.🤜🏼💯

 

[Alobos05]

Hey man how’s it going? I had a similar problem as you and tried everything here to no avail. Then I decided to upgrade the head gasket and switch to arp head studs to see if that would help. Well, when we took off the head there was a deformation by cylinder 1 which is the cylinder I was getting the misfire on just like you with the number 4. Had to send it to a machine shop to fix it. I know that’s a big jump from the do it yourself quick fixes and a lot of money but it’s better than paying for a new engine. Good luck to you and I hope you figure things out brother.🤜🏼💯

I havent had the time to do the compression test as I have been busy with work. The car is being send to a local mechanic next monday. Let see what they say. If you dont mind me asking- how much did your repair send you back? i have heard of that happening.

 

[Boosted5862]

I havent had the time to do the compression test as I have been busy with work. The car is being send to a local mechanic next monday. Let see what they say. If you dont mind me asking- how much did your repair send you back? i have heard of that happening.

I don’t mind but it’s still at the shop so I don’t have an exact price yet but he said on the phone around $500. Now he already had the head off for the upgrades so it would probably be a good bit more for the labor. I’ll let you know exactly as soon as I get it back, hopefully in the next few days. Good luck brother.

 

[Paul V]

Please let me know what the results were for you guys. I have a misfire in cylinder 4 and have the exact same symptoms,only on startup,no white smoke, I do seem to have noticed less coolant in my tank,maybe an inch under minimum. Im not sure if I just never noticed before though.I have a 2019, and have ford procal tune, airaid tube,mbrp catback, jlt catch can, blow off bypass valve,and I have changed the fuel pressure sensor. I have 28k miles and have changed my plugs 4x just to be cautious. This misfire started like a month ago and was really inconsistent,but now it does it every other day I have a pending misfire for cylinder 4 and first 1000 misfire. I want to get a compression test,but would like to know would the evap valve line cause this,as I have not changed that out yet? Thanks in advance.