[BulkBen]

Hi Guys,

I have temporarily escaped the other Dad's in the XBimmers forums, need some help from you guys who are a bit more familiar with working the B58.

Recently bolted on a Vargas GC turbo, having gone from stage 2+ (Dorch stage 2 and down pipe). At the same time I have gone from E30 to E50.

I'm working with Cary Jordan's guys on a remote custom tune, currently on second revision with what looks like very safe boost numbers (under 24psi and mild timing) so far, all logs are clean.

Anyway, I went WOT up a hill the other day and the power felt incredibly strong - as if it was over-boosting, until it hit redline that is. Very quickly the car seemed to shutdown and faults appeared.

Unfortunately I wasn't logging at the time.

Directly after the car was running really rough, I shut it down and restarted, and it was ok (although faults were still there). I ran the diagnostics later with BM3 and the codes in the pic appeared.

I cleared all of these and all now seems fine after doing some WOT runs, but a little concerned I don't know what caused the issue.

Any ideas?
I'm confident my E50 mix is sound, plenty of fuel was in the tank and like I said the logs I have done on the same revision show no detonation and boost seems conservative.

I am still running the stock charge pipe and at first I thought I'd blown that, but now codes are cleared it seems to be running perfectly fine.

- Just realised these logs are too long, can't get the detail I need this way: https://www.bootmod3.net/log?id=6010...729b570c2b1c51

[Glemm1970]

What candles are worth? Stoke?

[TheFanatic]

what you'll want to do is find a strait road where there is no traffic. drive just fast enough to go safely into 3rd gear (5th would be better but I wont promote going that fast), start the log, then floor it while staying in the same gear (manual mode). Go to red line or near red line and back off end log. That should get us some clean logs to look at as well as provide enough engine load to see problems if they arise.

[Ifellapart]

When you say you hit redline, do you mean you actually hit redline? like fuel cut off redline?

[T_H_O_M_A_S]

cylinder 5 and b58 do not match very well...

[chris-c]

Originally Posted by Ifellapart

When you say you hit redline, do you mean you actually hit redline? like fuel cut off redline?

No, 7500RPM or there abouts.

Change up dont just come off as you'll certainly see some boost spikes

[G.Newt]

Originally Posted by chris-c

No, 7500RPM or there abouts.

Change up dont just come off as you'll certainly see some boost spikes

Isn't 7,500 rpm way past redline?

[Ifellapart]

Originally Posted by G.Newt

Isn't 7,500 rpm way past redline?

its 500 rpm past it. I think well within fuel cut off wonder if that would be the reason someone would get misfires. Wonder what OP was at.

[MTWO]

Either plugs or maybe turbo adjusted too stiff?

[BulkBen]

Hey Guys,

Many thanks for the responses so far. I have some shorter logs which I think tell the story.

So, the problem doesn't happen when logging in a selected gear, ie 3rd or 4th, here is an example. You will see boost deviates a bit but nothing major:

https://www.bootmod3.net/log?id=6011...729b570c2b205e

The next log I did while going up a hill, WOT and kick down activated. This is what I was going when it went into limp mode. It didn't do it in this log, but clearly wasn't happy.
You can see boost is spiking a lot higher than the target and timing is all over the place too.

https://www.bootmod3.net/log?id=6012...729b5687b6826a

Someone mentioned plugs, I have changed those to what CJ recommended, I'm assuming they were gapped correctly but need to confirm. Surely that wouldn't affect boost though?

Btw, my redline is 7000rpm, that's when the motor hits the limiter and when I am backing off. If I don't need to bounce it off the limiter, I'll start backing of at more like 6800 rpm now.

[TheFanatic]

Originally Posted by BulkBen

Hey Guys,
https://www.bootmod3.net/log?id=6012...729b5687b6826a

Your high pressure fuel pump is crashing in this log. target is 2300psi and it drops to 700 something in one spot and 900 something in another. granted it looks like when you shift but I don't think it's supposed to drop that much, someone with more incite will have to let us know. I don't normally see logs where there is shift points so though so that might be normal

[Jay5k]

Originally Posted by TheFanatic

Your high pressure fuel pump is crashing in this log. target is 2300psi and it drops to 700 something in one spot and 900 something in another. granted it looks like when you shift but I don't think it's supposed to drop that much, someone with more incite will have to let us know. I don't normally see logs where there is shift points so though so that might be normal

The hpfp does drop during shift depending on what dorch setting you have in the bmw config (old or new), but I've never seen it drop like that. Also CJ uses his own hpfp mapping. Honestly did not have a good experience with him for my 91. It took over 20+ revisions to finish my 91 map. Boost was all over the place, knocking consistently, boost oscillating on partial throttle, and he takes forever.

PJ did my E50 tune and it was great.

https://datazap.me/u/jptsunga/pj-e50...6-17-18&solo=7

You're just going to have to be patient with CJ and pray he don't fuck up your car.

https://datazap.me/u/jptsunga/pj-e50...a=3-5-7&solo=7

This is a base map from Paul.

https://datazap.me/u/jptsunga/b58-vt...log=0&data=3-5

This is CJ on like the 14th revision lol.

[luca10]

So I can't seem to read the logs but from what others are saying about fuel rail pressure dipping, that would def cause a misfire and sudden lose of power.

Funny enough though, I had this same exact situation happen to me last week. I was driving and all at once, car misfired and went into Limp mode with fuel shut off to multiple cylinders.

So I did the same thing, re flashed car, reset adaptions and car drive perfectly normal. People are saying it might be due to spark plugs but I just replaced the plugs maybe 2k miles ago. I just changed them again yesterday just Incase.

But yea, still don't really know what happened, my guess is if timing corrections were all over the place and fuel rail pressure dipped causing misfire, the cylinders might have cut fuel out to prevent further damage and that's why codes came up, etc.

A week later car is still driving normal so let's hope it was just a minor situation!

[BulkBen]

Cheers Luca, I am not sure what is going on, but I am starting to think the fuel pressure may be the issue.

I ran an updated map from CJ, seemed to do the trick at first then had the car go into limp mode again.

It doesn't seem to have an issue in a set gear, but when going through the gears it doesn't like it.

Can someone look at these two logs and tell me if the revs dropping is normal?

See after the gear changes the revs go up, then dip, before they rise again. I can't see how that could be normal, may well coincide with the drop in fuel pressure too.

https://www.bootmod3.net/log?id=6016...0b4321457c1512

https://www.bootmod3.net/log?id=6016...0b4320bdf20399

[BulkBen]

Ok, when you look at revs, fuel pump target vs actual and Lambda it all seems really clear.

On gear changes when fuel pressure drops the AF ratio goes from 13 - 19, this seems to correspond with the throttle closing (even though I am flat on the pedal).