Throttle tip-in issue/stumble (3.0 5-speed)

[Effduration]

Would you please test fuel pressure after the Hengst installation? There was a bad batch of Hengst fuel pressure regulators (installed in filter) and I had one on my E39. It generated fuel pressure of 60psi causing the car to to run rich.

[andrewwynn]

It’s common for the filler/FPR to mask low output fuel pump. Did you ever estimate your engine on hours?

My money is on weak fuel pump.

Sadly a real pita to test there's no test port. You have to add in a T between the pump and filter (though not difficult if you have the under belly off from filter change)

[80stech]

That's pretty much all wrong andrewynn.
The filter and regulator can't mask a bad fuel pump, the test port is on the rail, that's the part that counts. Testing (pressure) between the pump and filter only would only give an indication of restriction (plugged fuel filter.) Testing at the rail and under load eliminates fuel supply as being a problem.

[Masospaghetti]

I have a new fuel pump on order, I figured this would be a reliability improvement if nothing else. I also pulled some data using BMW Logger (attached) if anyone of ya'll have used it. The area of interest to me is between 31 sec and 33 sec where a hard stumble was experienced. Notice the lag between throttle application (light green line, TPS) and any rise in RPM (dark green line).

[80stech]

Another long shot you could try is to check the connectors in the E-Box but you should really look at getting that firmware update.

[paramax55]

My X5 5-speed does the exact same thing. I've never tried to fix it because I know the cause and I've just never felt it worth the trouble to fix it. It's the off idle tip-in map.

I've had two e30s that did this exact same thing in the past. The first car was just an eta and it drove me crazy. I figured it was just an old car and running bad. When it was wrecked, I bought an "i" car and used the tranny from the eta to make the newer one a 5-speed. It had the same off-idle problem so I knew it was a BMW thing. I turbo'd it and put in big injectors, so I was forced to remap it. I used a Moates eeprom emulator and free software (I don't remember the name). But the definition file called the map "throttle enrichment" or something like that. Once I fixed that map, it was smooth as silk.

I'm pretty sure that BMW kept that map super leam to meet EPA regulations. Seeing as how there are so few 5-speed X5s out there, I figure the complaint level was fairly low. After the maintenance issues I had with a lowered, boosted e30, I had no desire to f-@k with my X5. I just want it to go long periods without breaking down any more. I hate sitting on the side of the road.

[Masospaghetti]

That's disturbing if this is how it was when new! I've had lots of different makes and models with 5-speeds (mostly non-premium brands like Chevy and Honda) and never had any gripes like this. Can you elaborate on how the remap would be done? Edit: Looks like there's a sort-of how to on the E46 forum: https://www.e46fanatics.com/threads/...uning.1082287/


I dug deep into EEPROM programming and remapping on a Fiero years ago but that was because it was a custom job with a different engine and computer.


@80stech - I do still plan on getting the firmware update. It's just hard to find time to get to the dealer.

[paramax55]

I haven't remapped anything in about 10 years and I did the e30 about 15 years ago but... the bin file is on eprom or eeprom. You have to remove that chip and replace it with something that has your custom information on it. Moates (i'm not sure if they still exist) was big into Ford Mustang programming. One of their products was an eprom emulator that took a usb cable. You would go online and get a bin dump for your model and a definition file for the same. The definition file separated the 1's and 0's into maps that could be changed. You could then write your new bin to the emulator and plug the emulator into the socket where you removed the eprom from. You could then make changes on the fly if you kept a laptop in the car.

There may be better ways now, but I doubt it on an e53.

[Happy]

Originally Posted by paramax55

There may be better ways now, but I doubt it on an e53.

There is.. Active Autowerk. But it’s going to cost.

https://store.activeautowerke.com/pr...iant=780147815


E53 RiPPeR
XOuTPoST jUNkiE
ReVELaTiON 22:21

[paramax55]

Moates is still there. The Ostrich is the emulator that I used. It's $175.00. The software TunerproRT. It's $39.00 for the pro version. I don't remember what the $$ gets you, I think it was just a splash screen, but it's good software. Well worth the $39.00.

You can do a search for e53 bin files and Tunerpro definition files for the e53 and you should be able to find a rabbit hole pretty easily that will keep you up past your bedtime.