(Diagnosing Logs) FBO 2007 E92 335i MHD Stage 2+ v9 Log

MkfnBimmerBoy

New Member
Aug 14, 2020
6
1
0
Hey everyone.

Been running a JB4 G4 in the car for about 6 months since I got it. Car has 66k miles on it, DCI, Catless DP, CP Tial BoV, stock inlets, turbo and vacuum side catch can, PE exhaust, 1 step colder plugs, delphi coils (coils and plugs installed within 5k miles).

I just recently switched over to MHD stage 2+ and started logging after using map 1,2, and 5 on the JB4 with no issues. After the first log I experienced misfires in cylinder 6.

Upon looking at the log I noticed the LPFP, fuel rail, and timing were seemingly troublesome. I have my suspicions that I need to replace the LPFP and possibly injectors.

Here is the log for anyone who is interested!


Any input would be appreciated!

Devin
 

KClemente

Sergeant
Nov 26, 2019
280
145
0
Ride
E90 335i
Did you convert over to flash only or are using the ots as a backend flash? If you have a JB4 with a flash tune, you must set it to 4/2 (backend flash mode) and you have to log via the jb4 itself with the data cable or wireless connect kit. MHD logging with a JB4 connected isn't going to work as intended

Reason why your fuel pressures are dropping is most likely because of the JB4's fuel open loop (fol) setting which manipulates and tricks the dme into thinking theres a low fuel pressure so it can command the pumps to run harder. Or your lpfp is just crashing which does happen on higher mileage cars even on pump gas alone
 

MkfnBimmerBoy

New Member
Aug 14, 2020
6
1
0
Did you convert over to flash only or are using the ots as a backend flash? If you have a JB4 with a flash tune, you must set it to 4/2 (backend flash mode) and you have to log via the jb4 itself with the data cable or wireless connect kit. MHD logging with a JB4 connected isn't going to work as intended

Reason why your fuel pressures are dropping is most likely because of the JB4's fuel open loop (fol) setting which manipulates and tricks the dme into thinking theres a low fuel pressure so it can command the pumps to run harder. Or your lpfp is just crashing which does happen on higher mileage cars even on pump gas alone

I am not using a backend flash. The JB4 is installed but it is set to map 0. From my understanding that means it is completely off and I should be able to run a flash map from MHD.
 

KClemente

Sergeant
Nov 26, 2019
280
145
0
Ride
E90 335i
I am not using a backend flash. The JB4 is installed but it is set to map 0. From my understanding that means it is completely off and I should be able to run a flash map from MHD.

You didn't specify what your menu 4 is set to. My guess is that it's currently set to 4/3 (Stock flash mode). If you want to run flash only, I'd set the JB4 menu 4 to setting 4 (speedo 4/ tacho 4) which sets it into flash only mode (JB4 for gauges only) so it really isn't interfering with anything. Or remove the JB4 completely.

Or set it to 4/2 and run one of the free backend flash maps. But you have to log via the jb4. It's really up to you whether or not you want your JB4.

I only run my JB4 in 4/2 (backend flash mode) and the Map 0 operation is different than the other modes.

I would start off with an upgraded LPFP and see from there. I super highly doubt it's your injectors because that low of a fuel pressures lpfp and hpfp will cause a misfire.
 
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MkfnBimmerBoy

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Aug 14, 2020
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You didn't specify what your menu 4 is set to. My guess is that it's currently set to 4/3 (Stock flash mode). If you want to run flash only, I'd set the JB4 menu 4 to setting 4 (speedo 4/ tacho 4) which sets it into flash only mode (JB4 for gauges only) so it really isn't interfering with anything. Or remove the JB4 completely.

Or set it to 4/2 and run one of the free backend flash maps. But you have to log via the jb4. It's really up to you whether or not you want your JB4.

I only run my JB4 in 4/2 (backend flash mode) and the Map 0 operation is different than the other modes.

I would start off with an upgraded LPFP and see from there. I super highly doubt it's your injectors because that low of a fuel pressures lpfp and hpfp will cause a misfire.

Hey thanks for the tip I didn't realize that was a menu option for JB4.
The problem is I have a JB4 G4 which is an older version and it does not have the flash friendly options that the G5 must have. Map 0 states it completely disables the JB4 so do I have to physically uninstall it to run MHD flash tunes?

I plan on upgrading the LPFP but what do you think about the fuel rail numbers? does anything look suspect there or could it be a consequence of the LPFP being weak?
 
Last edited:

KClemente

Sergeant
Nov 26, 2019
280
145
0
Ride
E90 335i
Hey thanks for the tip I didn't realize that was a menu option for JB4.
I plan on upgrading the LPFP but what do you think about the fuel rail numbers? does anything look suspect there or could it be a consequence of the LPFP being weak?
No problem. Jb4 takes a while to learn and setup properly and I highly suggest using their backend flash maps unless you want to get a custom tune made.

I love my jb4 because i’m upgraded twins and the ability to change boost targets has been real nice so far.

Your low rail pressure is highly influenced by your lpfp. Depending on your budget and skills you can diy walbro 450 or 535 and have more fueling than you’d need for a while.

Or buy a lpfp kit from any of these vendors and call it a day
 

MkfnBimmerBoy

New Member
Aug 14, 2020
6
1
0
No problem. Jb4 takes a while to learn and setup properly and I highly suggest using their backend flash maps unless you want to get a custom tune made.

I love my jb4 because i’m upgraded twins and the ability to change boost targets has been real nice so far.

Your low rail pressure is highly influenced by your lpfp. Depending on your budget and skills you can diy walbro 450 or 535 and have more fueling than you’d need for a while.

Or buy a lpfp kit from any of these vendors and call it a day

I will be able to do the LPFP myself.

The problem is I have a JB4 G4 which is an older version and it does not have the flash friendly options that the G5 must have. Map 0 states it completely disables the JB4 so do I have to physically uninstall it to run MHD flash tunes?

Also what would you say about the timing corrections happening at WOT on almost all cylinders? Fuel related again?
 

KClemente

Sergeant
Nov 26, 2019
280
145
0
Ride
E90 335i
I will be able to do the LPFP myself.

The problem is I have a JB4 G4 which is an older version and it does not have the flash friendly options that the G5 must have. Map 0 states it completely disables the JB4 so do I have to physically uninstall it to run MHD flash tunes?

Also what would you say about the timing corrections happening at WOT on almost all cylinders? Fuel related again?

Ouch that's an ancient board. Like I said though, it all depends on how much having a JB4 is worth it to you. In my opinion its already saved my ass a bunch of times. I would upgrade that board to the G5 if you decide you want to retain a JB4, but for now I would remove it completely and focus on the LPFP.

Timing corrections can be weird and my guess is they started correcting early on due to your overboost at around 3800 rpm. How's your spark plug gap looking? I usually recommend 0.020" to 0.022" for pump gas. For reference, I run my 97506's at 0.018" on ethanol and 30 psi.
 

MkfnBimmerBoy

New Member
Aug 14, 2020
6
1
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Ouch that's an ancient board. Like I said though, it all depends on how much having a JB4 is worth it to you. In my opinion its already saved my ass a bunch of times. I would upgrade that board to the G5 if you decide you want to retain a JB4, but for now I would remove it completely and focus on the LPFP.

Timing corrections can be weird and my guess is they started correcting early on due to your overboost at around 3800 rpm. How's your spark plug gap looking? I usually recommend 0.020" to 0.022" for pump gas. For reference, I run my 97506's at 0.018" on ethanol and 30 psi.

My plugs are gapped to .022".

I see the overboost you are talking about.

I will update the G4 board eventually but not now as I'm focused on getting my car dialed for next week because I have a rally event that goes from the east coast to Cleveland and back.

As far as LPFP i'm torn between the bucketed and bucketless version and I also need to get it asap as the rally starts next Thursday...
 

KClemente

Sergeant
Nov 26, 2019
280
145
0
Ride
E90 335i
Hm with all that's going on it might be hard to get a pump (bucketed or bucketless) by thursday. Here's an amazon prime link to a walbro 450 but for me it says delivered on thursday and I don't know if itll be any different for you.

Building a simple diy kit takes four parts: the fuel pump, 3/8 (10mm) plastic fuel tube for ethanol (auto parts rubber fuel line for pump gas is fine), this so you can adapt the oem quick connect to your Walbro, and lastly, some hose clamps. The 450 fits perfectly in the oem bracket inside the bucket already.

If going stage 2 pump, I would go with bucketed. Just letting you know off the bat, if you're going to diy a walbro 450, I highly recommend skipping the whole venturi part of it and just run the pump straight to the feed line. I've had no issues with low fuel in the tank. Venturi's to my understanding need to be properly sized for a certain pump and any vendor worth their beans have tested their venturi's (if they choose to include one) already.

Though I understand that parts can take a bit of time to arrive so you may just want to find a vendor that can get a kit to you in time.
 

MkfnBimmerBoy

New Member
Aug 14, 2020
6
1
0
Hm with all that's going on it might be hard to get a pump (bucketed or bucketless) by thursday. Here's an amazon prime link to a walbro 450 but for me it says delivered on thursday and I don't know if itll be any different for you.

Building a simple diy kit takes four parts: the fuel pump, 3/8 (10mm) plastic fuel tube for ethanol (auto parts rubber fuel line for pump gas is fine), this so you can adapt the oem quick connect to your Walbro, and lastly, some hose clamps. The 450 fits perfectly in the oem bracket inside the bucket already.

If going stage 2 pump, I would go with bucketed. Just letting you know off the bat, if you're going to diy a walbro 450, I highly recommend skipping the whole venturi part of it and just run the pump straight to the feed line. I've had no issues with low fuel in the tank. Venturi's to my understanding need to be properly sized for a certain pump and any vendor worth their beans have tested their venturi's (if they choose to include one) already.

Though I understand that parts can take a bit of time to arrive so you may just want to find a vendor that can get a kit to you in time.

Bucketed seemed to be the better option imo as well. If i'm not able to upgrade the pump before the rally, the stock pump will hopefully hold up for the time being.

Thanks btw I appreciate all your input!
 
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