I have a MSII V3 latest code running fuel only on an otherwise standard RV8 3.5. I'm using the stock ignition (distributor) and cold start circuit (Bosch extra air valve) but with the cold start injector disconnected. Hot starting is ok.
A cold start - anywhere under about 15C - requires a deal of churning, but it does eventually start. When it does the warm up idle is fine. When I switch on I can hear the pump slow up after a second or so - so I'd guess it's pressurising the rail correctly. Opening the throttle slightly doesn't seem to help.
The enrichment is 152 at 0C and pretty linear to 100 at 71C. Pulse width is 10 at -40C and 2.6 at 71C. IIRC pretty well the defaults.
Big snag is of course knowing whether it is too rich or weak. The wideband sensor doesn't seem to give a consistent readout at cranking - even if I knew what the mixture should be for cold starting. ;-)
Cold starting
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Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0). For tuning/troubleshooting questions, please attached a datalog and your MSQ file to your post.
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
Cold starting
Dave P, London UK.
Rover V-8
MSII V3
EDIS
Tech Edge Wideband
Rover V-8
MSII V3
EDIS
Tech Edge Wideband
-
Bernard Fife
- Master Squirter
- Posts: 475
- Joined: Thu Oct 29, 2009 12:54 pm
Re: Cold starting
Dave,
You need to experiment with the -40C cranking pulse width. The cranking pulse widths need to be very close for the starting to work consistently at all temperatures.
If it is cranking and cranking and eventually starts, my first inclination would be to suspect that the cold cranking pulse width is too short. If it was too long, you would probably have to let it sit for a after cranking while before cranking again and starting.
So what I would do is change the cold cranking pulse width from 10.0 to 10.5, and see if that is better or worse. If it is better, I might try 11.0, and so on. However, if it is worse, try 9.5, etc.
Note that you only get one true cold start a day. It won't work to crank and start, then shut it off after a few seconds, then re-try thinking the engine couldn't have warmed up much. The reason is that there is now fuel in the manifold, the combustion chambers have warmed up quite a bit even from the few revolutions, etc. Also, you cannot use WB EGO feedback at all for cranking (it isn't even much use for warming up).
There is more here: http://www.megamanual.com/ms2/tune.htm#crank
Lance.
You need to experiment with the -40C cranking pulse width. The cranking pulse widths need to be very close for the starting to work consistently at all temperatures.
If it is cranking and cranking and eventually starts, my first inclination would be to suspect that the cold cranking pulse width is too short. If it was too long, you would probably have to let it sit for a after cranking while before cranking again and starting.
So what I would do is change the cold cranking pulse width from 10.0 to 10.5, and see if that is better or worse. If it is better, I might try 11.0, and so on. However, if it is worse, try 9.5, etc.
Note that you only get one true cold start a day. It won't work to crank and start, then shut it off after a few seconds, then re-try thinking the engine couldn't have warmed up much. The reason is that there is now fuel in the manifold, the combustion chambers have warmed up quite a bit even from the few revolutions, etc. Also, you cannot use WB EGO feedback at all for cranking (it isn't even much use for warming up).
There is more here: http://www.megamanual.com/ms2/tune.htm#crank
Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it.” - George Bernard Shaw