[JunkyardDogg]

I flashed v8 Stage 1+ map tonight and went out to do some data logs. Cruising to the highway felt fine (30-40mph). I get on the highway, shift into 3rd, and start my log. I floor it and get some wheel hop and I feel the car struggling to maintain traction but I continue accelerating and shift to 4th at 6K rpm and immediately after I notice my car is stuttering/shaking under any acceleration! I was scared I wasn't gonna make it home. No check engine lights. The more gas I give, the more it shakes. I even feel the gas pedal vibrating. Did something mechanical go bad?

[Bimmer_Bro]

Originally Posted by JunkyardDogg

I flashed v8 Stage 1+ map tonight and went out to do some data logs. Cruising to the highway felt fine (30-40mph). I get on the highway, shift into 3rd, and start my log. I floor it and get some wheel hop and I feel the car struggling to maintain traction but I continue accelerating and shift to 4th at 6K rpm and immediately after I notice my car is stuttering/shaking under any acceleration! I was scared I wasn't gonna make it home. No check engine lights. The more gas I give, the more it shakes. I even feel the gas pedal vibrating. Did something mechanical go bad?

How old are your plugs and coils? Do you have a aftermarket charge pipe?
Use version 7 or v9. There has been a lot of issues reported with MHD v8.

[JunkyardDogg]

Originally Posted by Bimmer_Bro

How old are your plugs and coils? Do you have a aftermarket charge pipe?
Use version 7 or v9. There has been a lot of issues reported with MHD v8.

I never changed the coils, car has 49K on it. The plugs maybe 10k. ER chargepipe.

Ok, but the car was running fine until the I got on the highway.

[Bimmer_Bro]

Originally Posted by JunkyardDogg

I never changed the coils, car has 49K on it. The plugs maybe 10k. ER chargepipe.

Ok, but the car was running fine until the I got on the highway.

Does the engine run rough now or is the vibration speed related ?

[nicky dj]

Originally Posted by JunkyardDogg

I never changed the coils, car has 49K on it. The plugs maybe 10k. ER chargepipe.

Ok, but the car was running fine until the I got on the highway.

Dude it's coils, plugs or HPFP. Remember a tune puts extra pressure on all these components, so they need to be in top shape. Check your logs and codes via the MHD app

[JunkyardDogg]

Originally Posted by Bimmer_Bro

Does the engine run rough now or is the vibration speed related ?

Runs rough at any speed, and shakes the more I accelerate

[Bimmer_Bro]

Originally Posted by JunkyardDogg

I never changed the coils, car has 49K on it. The plugs maybe 10k. ER chargepipe.

Ok, but the car was running fine until the I got on the highway.

Change the coils. Those are way too old
To be tuned with. Try v7 (my fav) or v9 (also good) and do a log from there.

[JunkyardDogg]

Originally Posted by nicky dj

Dude it's coils, plugs or HPFP. Remember a tune puts extra pressure on all these components, so they need to be in top shape. Check your logs and codes via the MHD app

But if hpfp failed I wouldn't have made it back home. I'm guessing misfires and the ses light did come on now that I recall. I'm planning to replace the coils and plugs soon.

[JunkyardDogg]

Originally Posted by Bimmer_Bro

Change the coils. Those are way too old
To be tuned with. Try v7 (my fav) or v9 (also good) and do a log from there.

Should I go with Delphi or eldor? Are the Bosch oem plugs good enough?

[Saif2018]

Originally Posted by JunkyardDogg

But if hpfp failed I wouldn't have made it back home. I'm guessing misfires and the ses light did come on now that I recall. I'm planning to replace the coils and plugs soon.

HPFP could be on its way out, (which means you may be able to drive it home) doesn't necessarily have to completely fail

Also plugs and coils are highly recommended before tuning, helps avoid a lot of misfire issues. Change your plugs to Bosch OEM ones or one step colder NGK ones, and replace the coils with Eldor ones.

As advised, you need to read codes and a Datalog would help to see what's going on with the engine as well.

V8 map has known issues, run V7 or V9.

[Saif2018]

Originally Posted by JunkyardDogg

Should I go with Delphi or eldor? Are the Bosch oem plugs good enough?

Eldor, if you can't get hold of Eldor then Delphi.

Bosch OEM plugs are good for 400whp+ good enough for what you want.

[JunkyardDogg]

Originally Posted by Saif2018

HPFP could be on its way out, (which means you may be able to drive it jome) doesn't necessarily have to completely fail

Also plugs and coils are highly recommended before tuning, helps avoid a lot of misfire issues. Change your plugs to Bosch OEM ones or one step colder NGK ones, and replace thw coils with Eldor ones.

As advised, you need to read codes and a Datalog would help to see what's going on with the engine as well.

V8 map has known issues, run V7 or V9.

I'm gonna flash back to stock until I get new coils/plugs.

Here's the datalog of the run
https://datazap.me/u/junkyarddogg/lo...og=0&data=3-20

[JunkyardDogg]

Originally Posted by Saif2018

Eldor, if you can't get hold of Eldor then Delphi.

Bosch OEM plugs are good for 400whp+ good enough for what you want.

Cool, last time I tried the one step colder NGK and got rough idle. I reinstalled a few times. Once I dropped in Bosch, much smoother.

[Bimmer_Bro]

Originally Posted by JunkyardDogg

Cool, last time I tried the one step colder NGK and got rough idle. I reinstalled a few times. Once I dropped in Bosch, much smoother.

Nothing wrong with the Bosch plugs. I am MHD stage2+ and i run the bosch plugs and coils. Never had any issues. Next time I might try the Eldor Coils just because I have heard good things.

[ky0u]

Did you run the code reader on mhd by any chance? It's most likely coils as everyone has stated but doesn't hurt to check.

I had the same thing happen a few thousand miles ago. Spirited pulls would have random minor hiccups. then one day I did a hard pull and suddenly rough, choppy engine. SES light on. blew out my cyl 4 coil.

[JunkyardDogg]

Originally Posted by ky0u

Did you run the code reader on mhd by any chance? It's most likely coils as everyone has stated but doesn't hurt to check.

I had the same thing happen a few thousand miles ago. Spirited pulls would have random minor hiccups. then one day I did a hard pull and suddenly rough, choppy engine. SES light on. blew out my cyl 4 coil.

I didn't, but I flashed back to stock this morning and it seems to run fine. Wouldn't a blown coil still show symptoms?

[ky0u]

Originally Posted by JunkyardDogg

I didn't, but I flashed back to stock this morning and it seems to run fine. Wouldn't a blown coil still show symptoms?

I would still check. Since you're running an OTS MHD map, it's unlikely it's the tune itself, but the tune might have exacerbated an underlying issue. In my situation my coil went bad gradually before it outright failed and threw a code. During this gradual period, my car would run perfectly fine until i really romped on it. Something in your ignition system might be on it's way out.

Would be worth it just to do an MHD code scan and see what's logged. you're for sure going to have some code recorded if your SES light turned on

[JunkyardDogg]

Originally Posted by ky0u

I would still check. Since you're running an OTS MHD map, it's unlikely it's the tune itself, but the tune might have exacerbated an underlying issue. In my situation my coil went bad gradually before it outright failed, something in your ignition system might be on it's way out.

Would be worth it just to do an MHD code scan and see what's logged. you're for sure going to have some code recorded if your SES light turned on

I'm gonna order some coils/plugs anyway. I'm back to stock tune and the SES light is gone but if it happens again ill check for codes.

[Saif2018]

Originally Posted by JunkyardDogg

Cool, last time I tried the one step colder NGK and got rough idle. I reinstalled a few times. Once I dropped in Bosch, much smoother.

NGK one step colder plugs need to be gapped correctly, otherwise you will have issues.

Personally wouldn't bother with them, unless you are pushing well over 400whp. Just stick to OEM Bosch plugs.

[nicky dj]

Originally Posted by Saif2018

HPFP could be on its way out, (which means you may be able to drive it home) doesn't necessarily have to completely fail

Also plugs and coils are highly recommended before tuning, helps avoid a lot of misfire issues. Change your plugs to Bosch OEM ones or one step colder NGK ones, and replace the coils with Eldor ones.

As advised, you need to read codes and a Datalog would help to see what's going on with the engine as well.

V8 map has known issues, run V7 or V9.

Originally Posted by Saif2018

HPFP could be on its way out, (which means you may be able to drive it home) doesn't necessarily have to completely fail

This. If HPFP is on its way out, you'll get misfires at high rpms, or high rev cold starts in the mornings where rpms spike up high without pushing on the pedal. Mine did both, 2 weeks later HPFP was dead on start.

[Bimmer_Engineer]

Originally Posted by JunkyardDogg

Cool, last time I tried the one step colder NGK and got rough idle. I reinstalled a few times. Once I dropped in Bosch, much smoother.

I actually tried the same ngk plugs when I was chasing some timing corrections on 1+ and had the same experience. The timing corrections were still there and the idle was also rougher...