223 replies to this topic

[DaveyC]

Nope, one of the only things I haven't changed. Worth a try though.

[CHILL Gone DUTCH]

i think the pressure for the regulator is different from the manifold pressure 

 

worth a read 

 

http://www.vx220.org...-fuel-pressure/

[Pollet]

Hi from Barcelona too.

 

I´m the Speedster with misfire problems. It appears doing the learning with the upgrade of blue injectors and 77mm pulley.

 

Since yet we changed differents maps who works ok in the other cars, TMAPS, fuel rails, injectors, fuel regulator, coil packs, sparks, fuel filter, primary lambda, battery, water pump and thermostat. Well, a "new" engine is now fitted and running, but with misfires too, so I think is something extern at engine.

 

The earth conections are all ok, is the first that Peter tell me to check, and nothing strange, no bad conections in two motors.

 

Next day I will try with another cat from one of the cars in the garage, check the knock sensor conection and try with another primary lambda.

 

In fact, in the last engine cracked (my fault adding too much advanced, TOO MUCH!), I tried to add fuel in the fuel table (talking in OBD Tuner) only when misfires appear. The misfires dissapear, and the car was running ok, but the engine was more heated respect the stage 2 (OEM radiator, now with new engine dual pass fittef). I´m not sure if is for the increase of power, or for add fuel manually.

 

I´ll continue trying things, but I don´t have more ideas about what colud be, so the last step is turn to add fuel manually.

 

Hope we find a solution.

Edited by Pollet, 26 January 2016 - 06:39 PM.

[CHILL Gone DUTCH]

what are your AFR at the 2000 rpm missfire 

[DaveyC]

Im at 14.7:1 or very close Noticed that adding loads more fuel just masked the problem I.e. misfire went away but car made half as much power and drove really sluggish (did this on a dyno).

[CHILL Gone DUTCH]

if your afr is at 14.7 its unlikely to be fuel shortage 

have you tried removing the pipe from the inlet manifold and blowing and sucking on to the fuel regulator 

[CHILL Gone DUTCH]

nice know your not the only one

[Pollet]

Im at 14.7:1 or very close Noticed that adding loads more fuel just masked the problem I.e. misfire went away but car made half as much power and drove really sluggish (did this on a dyno).

In my case, add more fuel mask the problem (probably, could be the solution?), I don't feel any lose of power. In fact, when I modify the advanced, in last moment the car runs too much, so in my car, load fuel manually is not the worst solution.

[Exmantaa]

Im at 14.7:1 or very close Noticed that adding loads more fuel just masked the problem I.e. misfire went away but car made half as much power and drove really sluggish (did this on a dyno).

 

Just re-reading your issues; can you post a recent log with your problem?

 

I just checked your log from 15-08-08 in OBD and where the strange rpm happens I see some weird spikey throttle behavior. Not only from the throttlebody, but it's already in the raw voltage signal from your pedal...

Could be that it's because your foot is moving a bit from the stuttering while driving, so it's good to make a decent log with a steady (increasing) throttle of the problem area.

[vocky]

Davey's fuel pressure does seem to work correctly, it has been checked with and without the vacuum pipe connected on the FPR.

 

 

[Rosssco]

Interesting...

 

I'm having similarish problems with my car (2.4 bottom, rebuilt head, external trigger wheel, 3.1" pulley, Siemens 630cc injectors, standard fuel pump etc.). They are more intermittent however, as sometimes there is no misfire, sometimes there is..

 

The misfire now seems to be restricted more to a lumpy idle, where it feels its running on 3-cylinder below 1k rpm.. Above that its ususlly pretty good (still on the base map - didn't want to calibrate fuel trims till I'd resolved the misfire issue), although occasionally (like today), I get a mis-fire around 2k rpm, which smoothes out about this, but is also load dependant (i.e. greater throttle demand increases it..)..

 

I've also had a few new sensors etc. and redone the injector clips.. I also get a P0141 error code which is odd as I thought OBD-Tuners deleted the 2nd lambda..

[smiley]

Rosco,

 

Can you post your map, or a screenshot of the transient tab?

 

After mounting my harrop, changing fuelrail and injectors I had an issue with my new basemap, and had to alter

my M62 map to the new injectors, and drive home like that. (engineers place is 150km drive for me)

I drove slow, due to the M62 map, but got home fine.

 

First small test with the new harrop basemap was horrable at idle once warm. (close to cut off)

 

For me it´s very early to draw conclusions, but looking at dave´s transient, and my new basemap transient it´s pretty different to my M62 based transient.

I am curious on how your´s look´s. (my engine has cam overlap though, due to stage 1 cams. Peter send me a specific altered transient basemap for that after my B207 setup) 

 

The transient table is complete hocus pocus for me, but the difference intrigued me.

Edited by smiley, 27 January 2016 - 01:41 PM.

[DaveyC]

 

Im at 14.7:1 or very close Noticed that adding loads more fuel just masked the problem I.e. misfire went away but car made half as much power and drove really sluggish (did this on a dyno).

 

Just re-reading your issues; can you post a recent log with your problem?

 

I just checked your log from 15-08-08 in OBD and where the strange rpm happens I see some weird spikey throttle behavior. Not only from the throttlebody, but it's already in the raw voltage signal from your pedal...

Could be that it's because your foot is moving a bit from the stuttering while driving, so it's good to make a decent log with a steady (increasing) throttle of the problem area.

 

Just took a look at that the log, the throttle pedal only fluctuates for the first few seconds, after that the voltages are constant at 4.34 and 1.58. The throttle valve does fluctuate, but I thought this was normal?

 

I was sat in neutral for this log so my foot was pretty steady.

[Exmantaa]

Arfe we talking about the same log?

These are screenshots of your 15-08-08 "2 weeks after rolling road with log:

(I zoomed in on the fluctuating rpm part)

 

 

Rpm fluctuations and the MAP fluctuations, caused (mostly) by the opening spikes of the throttlebody...

 

This is a shot of the same area, but then with the raw pedal voltages and the throttlevbody that follows this input. And a ~4v signal from the pedal resembles a fully pressed pedal for the ecu!!

 

 

 

Can you try to make a new log with a steady pedal and then slowly press it to increase the revs? Key is to aim for a smooth pedal input...

[DaveyC]

I see the confusion... That's because it is a fluctuating pedal. I'm blipping the throttle at those spikes to highlight the really shitty response. The bit of the log with the misfires is between the two sets of spikes. Look at 110-120 seconds. My foot is on the pedal here at a constant position to keep the revs at 2000. Car is misfiring repeatedly in this section.

[Exmantaa]

PS; you see that all rpm fluctuations in that log are related to MAP fluctuations.  (So most likely not related to a fuelling issue...)

 

MAP pressure can deviate by a bad MAP sensor (wiring), but they normally go bad everywhere.

Or the MAP pressure in the intake manifold deviates due to the opening and closing of the throttlebody. And that is what you see here...

[DaveyC]

See post above.

[Exmantaa]

I see the confusion... That's because it is a fluctuating pedal. I'm blipping the throttle at those spikes to highlight the really shitty response. The bit of the log with the misfires is between the two sets of spikes. Look at 110-120 seconds. My foot is on the pedal here at a constant position to keep the revs at 2000. Car is misfiring repeatedly in this section.

 

A, so you were blipping th pedal... That explains...

(confused by this: "I was sat in neutral for this log so my foot was pretty steady...)

[Exmantaa]

So looking to the 110-120 section; that indeed has a steady throttle ( ) but fluctuating rpm.

It's in closed loop there (primary O2 switches between 1v and 0.1v), so it has enough fuel.

Only your ignition is a bit spikey and fluctuates between 20° and 17°... (check ign map and smooth it out in that area. Also try to make the idle ign settings identical a that same low load area in the ignition table.)

 

But not sure if you can capture a stuttering isue in a log, as that can be too slow. Also you talk about a shitty repsonse? (I would say from the log it responses pretty ok on your pedal input?)

[Exmantaa]

@Davey; I checked your mapping and in the area of that logged stuttering (just above 2000rpm and ~45KPa MAP) there is a big jump (around 10°) in your ignition values. The ecu interpolates between values,but I would blend that area more and see if that helps your issue there: