VEMS Community Forum

VEMS => Calibration & Mapping => Topic started by: Tony C on June 25, 2011, 03:46:40 PM

Title: Car seems guttless at WOT :-(
Post by: Tony C on June 25, 2011, 03:46:40 PM
Some one possibly give me a hand with my datalog please.
been trying to get the car responsive at WOT but it just seems flat and then slowly starts to pull,

the config and log is here,
http://www.capriracing.co.uk/vems/caprilog.zip
Title: Re: Car seems guttless at WOT :-(
Post by: GintsK on June 25, 2011, 04:15:43 PM
I am not familiar with particular (Rover?) engine. But is it knock limited? If it has 2 valves per cylinder may be you run too retarded. 20deg@3000 - even modern 4valve engines want more in most cases.
And seems your acceleration enrichment would be better if you run triple PW for 1/3 of fadeout time. Especially if you use overrun fuel-cut: then first particles of throttle movement is very important for keeping fueling in acceptable margins. You can try to temporary switch it off.

Do you use big injectors for application?

Gints
Title: Re: Car seems guttless at WOT :-(
Post by: Tony C on June 25, 2011, 05:18:51 PM
oh b@@@@@@@' for some reason the ecu file is corrupted,
and i have saved this file over the original file that had a totally different ignition map,
no wonder she has been running crap, as we had 28 degrees ignition all in by 3000rpm

Thing is i dont have a copy of the ignition map anymore :-(

Any Rover guys have an ignition map they can send me please :-(
Title: Re: Car seems guttless at WOT :-(
Post by: mattias on June 25, 2011, 05:29:13 PM
Don't you have a vemslog somewhere?
Title: Re: Car seems guttless at WOT :-(
Post by: Tony C on June 25, 2011, 05:43:24 PM
just looking now but i think the only recent one left is what i have uploaded now :-(
Title: Re: Car seems guttless at WOT :-(
Post by: Tony C on June 25, 2011, 05:53:57 PM
it looks like it has been this way since day one, the table reverted back to an old one we had to get the car running and not the new one we set up,
FFS this must be why she ran not as expected last weekend at santa pod,

Anyone assist with an ignition map for a RV8 4.6 please.
Title: Re: Car seems guttless at WOT :-(
Post by: mattias on June 25, 2011, 06:31:22 PM
A lesson learned maybe. Always press "Alt-L" or press the "LOG" button when you connect the tuning PC to your ECU. That way you will have an excellent history of what went on and when.

Can't really set you up with a proper map, but try 15 at idle, 20 @ 2000, 25 @ 3000, 30 @ 4000 to redline. Maybe a bit less at WOT and low rpm, maybe a bit more on low load/throttle. It's very easy to create using VemsTune, use the 'ctrl' and arrow keys and select multiple cells and the 'I' key to interpolate.
Title: Re: Car seems guttless at WOT :-(
Post by: Tony C on June 25, 2011, 07:03:12 PM
Cheers for the help mattias,
something like this?

(http://www.capriracing.co.uk/vems/ignition.gif)
Title: Re: Car seems guttless at WOT :-(
Post by: mattias on June 25, 2011, 07:21:32 PM
Looks like a good starting point. Make sure you have a few cells around idle with the same advance, or it might start 'hunting' for other reasons than just a VE tune or bad
injector settings.
More advance with lower pressure is normal, so you should really have more advance at the bottom rows than at 40 kPa, but most cars run with overrun fuel-cut at such low pressure anyway so it doesn't matter.
I'm guessing you'll cruise at 40 to 60 kPa, try having only 30 degrees at most there to begin with. 35 degrees can be excessive, but I really don't know these engines well.

To simplify things you could've used only 20-40-60-80-100 kPa. Too much resolution can just make it harder to work with.
Title: Re: Car seems guttless at WOT :-(
Post by: Tony C on June 25, 2011, 09:27:19 PM
right ran the car up the road with above table and lowered the throttle enrichment,
goes better now :-) i recon i can drop the enrichment a bit more yet,
Title: Re: Car seems guttless at WOT :-(
Post by: Tony C on July 11, 2011, 08:41:07 PM
car is running a lot stronger now cheers guys,

one other niggling thing i have never been able to sort out is this hot starting,
car starts great from cold and idles sweet right up to temp,
but if you turn the car off then restart when hot it runs for a few seconds with idle low then dies, if you catch it on the throttle and play it for a while it will idle after a bit on its own.
ideas please?
Title: Re: Car seems guttless at WOT :-(
Post by: Tony C on July 14, 2011, 06:28:16 PM
mmmmmmm.
went to use the car for work today and no idle, tried a few times then gave up,
went out and tried again tonight and still nothing you need to catch it on the throttle and use the throttle as the idle as soon as you let off it stalls,
took the stepper out and fitted it to a spare housing so i could see whats happening,
the stepper powers out but will not power back in any ideas?
was working fine when the car was put away sunday night :-(
Title: Re: Car seems guttless at WOT :-(
Post by: Tony C on July 24, 2011, 06:45:14 PM
regarding the above problem, uploaded the config to the ecu today as had 5 mins to get to the car,
stepper now poweres in and out again, but wont idle from cold need to blip the throttle a few times, and wont idle from hot start either need to do the same sort of thing,
any ideas? once its been reved a few times it idles when hot,
Title: Re: Car seems guttless at WOT :-(
Post by: Tony C on July 24, 2011, 07:15:45 PM
two logs while trying to start when hot (i hope), if some one would not mind taking a peek to see if im missing something,
im banging my head now, hope the ecu is not going into freak mode again like it did a few years ago when dnb needed to sort it out :-(

http://www.capriracing.co.uk/vems/latestcapri.zip
Title: Re: Car seems guttless at WOT :-(
Post by: mattias on July 24, 2011, 08:15:24 PM
I think you're pouring in too much fuel. Crank VE % should be similar to what you got in the VE table at the lowest RPM bin at 100 kPa. Tune that cell by using a very high gear and go WOT and up. Check out my config (link in signature below).

It would be better for anyone trying to help you if you would upgrade to 1.1.95.
If you get any problems after the upgrade, don't downgrade - upload logs and get help to solve any problems.
Title: Re: Car seems guttless at WOT :-(
Post by: Tony C on July 24, 2011, 09:17:27 PM
is it a straight forward upgrade?
or do things need changing like when i upgraded to 1.1.74?
Title: Re: Car seems guttless at WOT :-(
Post by: mattias on July 24, 2011, 09:19:23 PM
Upgrading from 1.0.x to 1.1.x is quite a big change, from 1.1.74 to 1.1.95 still requires review but not nearly as much.
Title: Re: Car seems guttless at WOT :-(
Post by: Tony C on July 25, 2011, 10:04:23 PM
tweaked a few things tonight car is a right pig to cold start, but hot starts sweet now,
have taken 3 logs one of cold start and 2 of bhot starts, if anyone can throw some light,
cheers to all who have helped me so far, :-)

files here: http://www.capriracing.co.uk/vems/latestcapri2.zip
Title: Re: Car seems guttless at WOT :-(
Post by: mattias on July 25, 2011, 10:19:30 PM
Try increasing cranking enrichment at the cold temperatures. But overall, the VE needs a good tune and you have a number of things in the config that should be fixed, but I won't bother unless you upgrade to 1.1.95.

There is no hot start in either of the "hot start" logs. Start the log before you crank it.. ?
Title: Re: Car seems guttless at WOT :-(
Post by: Tony C on July 25, 2011, 11:03:30 PM
Cheers for the reply mate,
i did start the log mate before cranking :-(

once we have moved and the car is at its new home in 4 weeks time i can upgrade the firmware,
dont want to dabble to much and then the car not work at all and need to rush around to get the car running to move it, ;-)
Title: Re: Car seems guttless at WOT :-(
Post by: mattias on July 26, 2011, 12:07:26 AM
The upgrade should be pretty much hassle-free if you're just rational about it. Any trouble or not, post vemslog, get feedback and/or improved vemscfg to upload, improve and repeat. It's a matter of a spending minutes, not hours to do it.
Either way,  what I can see still requires VE table tuning before being ready to go anywhere.

At least upgrade the wiring to the starter from the battery, most likely the ECU resets and VemsTune reconnects while the engine starts. When you're cold starting it the battery is probably fresh enough so that it wont reset.  It's the initial surge of current that causes the reset, dips below 8 Volts and you're in trouble. 
The ECU and engine management harness can have it's own main feed from the battery, that can also fix the issues since the voltage won't drop as much at the battery. If you are already setup that way, then there is no easy fix but better wiring or a fresh new (stronger) battery.
Title: Re: Car seems guttless at WOT :-(
Post by: Tony C on July 26, 2011, 12:39:05 AM
Hi Mattias
the wiring and battery are good and always has been (3 yrs ago) and has never caused any issues,
Tried to upload the new firmware and my laptop comes up error vemstune needs to shut down,
ok on the PC, im using windows 7 on the new laptop, is it something simple like access needs granting?
Title: Re: Car seems guttless at WOT :-(
Post by: mattias on July 26, 2011, 12:47:58 AM
W7 and it's "UAC" is a cause of headache on some computers.  Disable it or change properties on the shortcut that you start VemsTune with so that you run it as "administrator".
Title: Re: Car seems guttless at WOT :-(
Post by: Tony C on July 26, 2011, 01:05:46 AM
nope still comes up with error then shuts down, and vemtune is set as administrator now,
is there a newer version of VT? the one on pc works fine but that uses XP.
Title: Re: Car seems guttless at WOT :-(
Post by: mattias on July 26, 2011, 09:03:10 AM
Quote from: Tony C on July 26, 2011, 01:05:46 AMis there a newer version of VT?

http://vems.hu/vt/

Remove the old installation directory (Program Files\VemsTune) before install.