Why is my car dying out????

[MLP17]

I have been running Jb4 stage 2 with Zima DPs for over a year with no issues at all. Recently i installed BMS intakes and since then i feel the car has been running a little "rough".

For the last week when i start my car in the morning it has been acting very strange. The RPM's Jump to about 3k and then drop down to about 500 and it repeats about 2 or 3 times before the car acts normal. ( No CEL whatsoever).

This morning, i started up the car and the RPM's jumped up to about 3k and then fell so low the car turned off. I started it again and the same thing happened. The third time i started it the RPM's jumped again and then fell down to about 500-600 but the car didnt die this time. It just idled very roughly for a minute or two and then all was fine. (No CEL came on during this either)

Any idea why this could be happening?

[ShlemonboostedM]

Maf sensor ... Make sure there is no leaks .. If there none then just remove the intake and run stock airbox problem solved ..

[mrduder]

it's the intake causing this. others have had this issue as well. can't remember what exactly the problem was with the intake though. I tried searching on the app but the search function doesn't work on the app so I can't direct you to that thread. sorry. if you're on a computer you can find it. I want to say it's something like the way it's seated??? seems like most people with this problem is just with the BMS intake too. usually colder climates.

[MLP17]

Thanks guys! I most likely will just go back to stock intake because right now it feels like im driving an old junk car haha.

[CaryTheLabelGuy]

It's not the intake, it's the MAF sensors. When installing the MAF sensors in the new intakes, they are very tight. If you don't properly lube the rubber o-ring with oil before installation, the o-ring can get pinched and allow unmetered air to seep past them causing idle issues.

The other thing to do is to clean the MAF sensors with MAF cleaner while you have them out. If they get dirty, they can give false readings to the DME.

This is a common problem and is easily fixed.

[MLP17]

Originally Posted by CaryTheLabelGuy

It's not the intake, it's the MAF sensors. When installing the MAF sensors in the new intakes, they are very tight. If you don't properly lube the rubber o-ring with oil before installation, the o-ring can get pinched and allow unmetered air to seep past them causing idle issues.

The other thing to do is to clean the MAF sensors with MAF cleaner while you have them out. If they get dirty, they can give false readings to the DME.

This is a common problem and is easily fixed.

I had a feeling it could be this. I have cleaned the sensors and made sure they are plugged in properly but its still giving me problems.

[CaryTheLabelGuy]

Originally Posted by MLP17

I had a feeling it could be this. I have cleaned the sensors and made sure they are plugged in properly but its still giving me problems.

Did you oil the o-rings on the MAF sensors before installing? Are the sensors seated totally flush in their seats on the intake? Were they hard to push into their intake seats?

[MLP17]

Originally Posted by CaryTheLabelGuy

Did you oil the o-rings on the MAF sensors before installing? Are the sensors seated totally flush in their seats on the intake? Were they hard to push into their intake seats?

I had a performance shop install the intake along with a handful of other things So i'm not really sure. I already took it back over there and he double checked everything as well.

[CaryTheLabelGuy]

Originally Posted by MLP17

I had a performance shop install the intake along with a handful of other things So i'm not really sure. I already took it back over there and he double checked everything as well.

I'm almost positive they didn't install the MAF sensors correctly. They are not hard to remove and check yourself. You don't have to take the intakes out to get to the MAF sensors yourself. Unplug them and remove the star bit that's holding the sensor in the seat. Remove, clean with MAF cleaner, lightly oil the o-ring and carefully reinstall. Make sure the sensor is perfectly seated before screwing in the set screw.

[CaryTheLabelGuy]

Also, if you want to test the MAF sensors:

Unplug them both and start the engine. If the rough idle goes away, you have your culprit. don't run the engine for more than 30 seconds without them unplugged.

[MLP17]

Originally Posted by CaryTheLabelGuy

Also, if you want to test the MAF sensors:

Unplug them both and start the engine. If the rough idle goes away, you have your culprit. don't run the engine for more than 30 seconds without them unplugged.

Ok great idea. Ill try to get on this after work today. Ill let you know how it goes.

[CaryTheLabelGuy]

Originally Posted by MLP17

Ok great idea. Ill try to get on this after work today. Ill let you know how it goes.

You will get a CEL if you try this, but the DTC for the MAF sensors being unplugged is passive and won't hurt anything. It should auto clear after a few drive cycles unless you have a JB4 to clear it for you or a OBDII scanner.

[F80_edd57]

Originally Posted by MLP17

I have been running Jb4 stage 2 with Zima DPs for over a year with no issues at all. Recently i installed BMS intakes and since then i feel the car has been running a little "rough".

For the last week when i start my car in the morning it has been acting very strange. The RPM's Jump to about 3k and then drop down to about 500 and it repeats about 2 or 3 times before the car acts normal. ( No CEL whatsoever).

This morning, i started up the car and the RPM's jumped up to about 3k and then fell so low the car turned off. I started it again and the same thing happened. The third time i started it the RPM's jumped again and then fell down to about 500-600 but the car didnt die this time. It just idled very roughly for a minute or two and then all was fine. (No CEL came on during this either)

Any idea why this could be happening?

That's weird that you say that because my car too has just started doing this out of nowhere and it isn't the Mafs I've ran with and without Mafs many times previously and car had never acted as such , this kind of stalling /putting is almost Similair to a misfire but it isn't ,let me know if you get this issue figured out as I haven't been able to drive my car for past 2 days because of this issue

[MLP17]

Originally Posted by F80_edd57

That's weird that you say that because my car too has just started doing this out of nowhere and it isn't the Mafs I've ran with and without Mafs many times previously and car had never acted as such , this kind of stalling /putting is almost Similair to a misfire but it isn't ,let me know if you get this issue figured out as I haven't been able to drive my car for past 2 days because of this issue

What mods are you running?

I cleaned my MAFS last night and made sure they were properly connected and this did NOT fix the issue at all.

[CaryTheLabelGuy]

Originally Posted by MLP17

What mods are you running?

I cleaned my MAFS last night and made sure they were properly connected and this did NOT fix the issue at all.

Did you test the MAFs like I suggested yesterday?

[MLP17]

Originally Posted by CaryTheLabelGuy

Did you test the MAFs like I suggested yesterday?

I did not. I wanted to try one thing at a time. This only seems to happen on a cold start, so i wanted to try cleaning and reconnecting first and then see how the car starts in the morning. My car died out this morning as well

I will try what you suggested either today or tomorrow.

[F80_edd57]

It's not the Mafs this issue wouldn't show up out of nowhere if it were the Mafs these are Similair to a misfire problematic symptom. I have checked so far spark plugs which in changing out for brand new ones today,, coils ,fuel pump powers up,I've ran both map 0 and map 4 with jb4 to see if the tune was the problem and still same outcome . I even took off the jb4 to completely rule that out. Also if it were the maf jb4 auto clears these passive codes and you can run without 1 of the Mafs with jb4 . Besides the point this problem arose over night on 3 different cars ,his and another guy on this forum who posted under TSB recalls and he even took his into dealer and they still didn't fix the issue . I am beginning to Beleive it is due to bad battery or production date may come into play which can be software related maybe ? I am trying to rule out battery today . My mods are , Dp, Intakes, Methanol, jb4,muffler delete

[MLP17]

Originally Posted by F80_edd57

It's not the Mafs this issue wouldn't show up out of nowhere if it were the Mafs these are Similair to a misfire problematic symptom. I have checked so far spark plugs which in changing out for brand new ones today,, coils ,fuel pump powers up,I've ran both map 0 and map 4 with jb4 to see if the tune was the problem and still same outcome . I even took off the jb4 to completely rule that out. Also if it were the maf jb4 auto clears these passive codes and you can run without 1 of the Mafs with jb4 . Besides the point this problem arose over night on 3 different cars ,his and another guy on this forum who posted under TSB recalls and he even took his into dealer and they still didn't fix the issue . I am beginning to Beleive it is due to bad battery or production date may come into play which can be software related maybe ? I am trying to rule out battery today . My mods are , Dp, Intakes, Methanol, jb4,muffler delete

WOW!! So i really don't know where to start now, it looks like you have tried a handful of different things already. Please keep me updated.

[Roychimac]

I've got the same problem as well and also only during cold starts on colder days. It does seem like misfire or injector issue cuz same thing happened to my X6M when injectors were failing.

My mods are: flashed tune, dp, exhaust, BMC air filters.

On warmer days it starts fine. Hope one of us gets to the bottom of it. My production date was prob one of the earliest 2015 models made.

[4everkidd]

Originally Posted by Roychimac

I've got the same problem as well and also only during cold starts on colder days. It does seem like misfire or injector issue cuz same thing happened to my X6M when injectors were failing.

My mods are: flashed tune, dp, exhaust, BMC air filters.

On warmer days it starts fine. Hope one of us gets to the bottom of it. My production date was prob one of the earliest 2015 models made.

add one more to the mix here, also another Calgary candidate.

Car starts, roughly idles with big pick ups and drops and has stalled in the past.

No JB4 or flash here

Mods are : SSR intake, ARK catback

[CaryTheLabelGuy]

Originally Posted by 4everkidd

add one more to the mix here, also another Calgary candidate.

Car starts, roughly idles with big pick ups and drops and has stalled in the past.

No JB4 or flash here

Mods are : SSR intake, ARK catback

Clean your MAF sensors with MAF cleaner and re-install, making sure to lightly oil the rubber o-rings and insure proper sensor seating when re-installing.

[4everkidd]

Originally Posted by CaryTheLabelGuy

Clean you MAF sensors with MAF cleaner and re-install, making sure to lightly oil the rubber o-rings and insure proper sensor seating when re-installing.

Thanks for the heads up! I'm going to check and verify the following but I did properly lube and seat the MAF's during install.

I am only at 6000mi so I doubt dirty MAF's are the issue; that being said I did have oiled BMC filters installed prior to the SSR intakes.

I may try a cold start with the MAF sensors unplugged tonight.