[jessetaylor1]

I'm running a catless downpipe and Stage 2 Tune from VF Engineering.

I'm feeling the car hesitate sometimes most likely due to heat soak out of the stock IC and or fuel issues.

At what point do our cars start craving more fuel flow?

[Orange fever]

stage 2 for two years with just downpipe and tune with no heat soak nd I'm in So.California but m2's wants more after 400hp do a search threads about this....

[jessetaylor1]

Any idea why the car would feel like it's hesitating sometimes? Only thoughts could be the heat. It's been around 80-90 F past couple weeks.

[dcmac]

Everything I've been told is that if you are going Stage 2 you should be upgrading the IC. I did so and have had no problems thus far - in 90-100deg summer heat at altitude. For the $500 or so seems like a worthwhile upgrade.

[twin fed]

Originally Posted by jessetaylor1

Any idea why the car would feel like it's hesitating sometimes? Only thoughts could be the heat. It's been around 80-90 F past couple weeks.

Actually, I started to get some hesitation yesterday too for the first time. I am in NY and it has been hot as hell lately. But as soon as I started my car in the morning I could tell something was off. I am wondering it if is just some bad gas as the car has been perfectly fine, just installed installed a CSF intercooler too.

My only doubt about the gas is that it had been fine until just a little less then 1/4 tank. And the hesitation only happens with about 15% throttle, but if you get on it, it runs fine. I am gonna fill it up with some fresh 93 and see what happens.

[horsepower_and_hounds]

If your not logging with the tune then your just grasping at thin air. Every car reacts differently in different environments etc..... nobody can tell you what is going on if you can't see what it is doing.

[twin fed]

So mine finally threw a code today P0301 Cly 1 misfire. Gonna make an appt at BMW for annual oil change/service so I will just let them deal with it.

[jessetaylor1]

Originally Posted by twin fed

So mine finally threw a code today P0301 Cly 1 misfire. Gonna make an appt at BMW for annual oil change/service so I will just let them deal with it.

Let us know what happens.

[horsepower_and_hounds]

Example today.......ran the mountains hard then had to fuek up before heading home. Filled up with Exxon 93 then did some pulls on the highway. Tons of knock registered and major timing pull

It just did not feel right and still seemed to boost into the high 16's but had a lot of huge timing drops.....nothing but crap.

You would never know this if you weren't logging

[jessetaylor1]

Originally Posted by m2ruder

Example today.......ran the mountains hard then had to fuek up before heading home. Filled up with Exxon 93 then did some pulls on the highway. Tons of knock registered and major timing pull

It just did not feel right and still seemed to boost into the high 16's but had a lot of huge timing drops.....nothing but crap.

You would never know this if you weren't logging

I'm running Stage 2 from VF-Engineering so I don't necessarily have a way to data log.

[Nezil]

Originally Posted by jessetaylor1

I'm running Stage 2 from VF-Engineering so I don't necessarily have a way to data log.

I'm sure the VF tunes are very good, but not having the ability to datalog was one of the primary reasons I didn't go with VF. They're based in southern CA, where gas is known to be sub-optimal, so their map should take this into consideration, but without logging, there is no way to know just how your car is taking to the tune.

I believe if you buy a BM3 license, you can take a backup of your VF map so that you can re-load it whenever you want, and you can also take datalogs of your car running that map. At $500, it's not a cheap option, but how much is the cost of peace of mind.

Do keep in mind of course, that logging is only part of seeing what's going on. Interpreting the logs is the thing that takes experience. There is a fair amount of that experience in these forums, and several forum members are kind enough to provide feedback if logs are posted.

[twin fed]

Originally Posted by jessetaylor1

Let us know what happens.

Will do

[twin fed]

So I took my car into BMW today because the hesitation got worse, basically undriveable. The CEL came back on and a DRIVE TRAIN MALFUNCTION warning came on as well. I just got a call from my SA, they scanned the car and it is showing a misfire in all 6 cylinders. Thankfully I have not done anything to the DME, so whatever the issue is will be covered under warranty. Should I just tell them to swap in a M2C motor and call it quits

[cecaa850]

Originally Posted by twin fed

I just got a call from my SA, they scanned the car and it is showing a misfire in all 6 cylinders. Thankfully I have not done anything to the DME, so whatever the issue is will be covered under warranty.

Unless you got a tank of crap gas.

[425M2]

Would changing the spark plugs help?

[twin fed]

Originally Posted by cecaa850

Unless you got a tank of crap gas.

Don't think so. The car was running perfectly fine. Then one morning with a little more than a 1/4 tank, when I started the car I noticed right away that there was a problem out of nowhere.

[twin fed]

Originally Posted by 425M2

Would changing the spark plugs help?

It is in BMW's hands now, so I guess we will see, but I doubt it is just the spark plugs. I do not think that they would all go at the same time.

[cecaa850]

Originally Posted by twin fed

It is in BMW's hands now, so I guess we will see, but I doubt it is just the spark plugs. I do not think that they would all go at the same time.

Agreed. Trying to think of what they all have in common and all I come up with is the DME.

[twin fed]

Originally Posted by cecaa850

Agreed. Trying to think of what they all have in common and all I come up with is the DME.

I was thinking that or possibly the fuel pump, either high or low.

[cecaa850]

Originally Posted by twin fed

I was thinking that or possibly the fuel pump, either high or low.

True. Lean or rich would affect all cyls as well. O2's also.

[twin fed]

So I just got a call from my SA, he said that they cleared all the codes that showed a misfire in all the cylinders and road tested the car (with my permission) the CEL did come back on but only showed what I had initially diagnosed, a misfire in cyl 1. So they ended up replacing the cly 1 injector, plug and coil and he said that fixed the issue. I asked why it showed a misfire in the other 5 cylinders and he said that it was most likely a brief misfire that the DME corrected for when the number 1 cyl injector went. So I will pick it up later and see what happens. I'll let you know.

[cecaa850]

Originally Posted by twin fed

So I just got a call from my SA, he said that they cleared all the codes that showed a misfire in all the cylinders and road tested the car (with my permission) the CEL did come back on but only showed what I had initially diagnosed, a misfire in cyl 1. So they ended up replacing the cly 1 injector, plug and coil and he said that fixed the issue. I asked why it showed a misfire in the other 5 cylinders and he said that it was most likely a brief misfire that the DME corrected for when the number 1 cyl injector went. So I will pick it up later and see what happens. I'll let you know.

Makes sense. I've seen dead holes cause misfires on other cylinders as well. The DME measures the amount of time that it takes the crank to rotate from one cyl to the next using the crank sensor, If one of those times is slower than the rest it thinks that hole isn't making as much power as the rest of them and it will trigger a misfire on that hole. If it's bad enough it can affect the other cylinders time's as well causing the other mis fire codes.