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difficulty starting

Posted: Sun Feb 14, 2010 1:03 pm
by twardnw
1.8l 8v
Digi injectors
Hall input
direct coil control
MS2 on V3, 2.886 code

When I attempt to start the car, it cranks for a second or so, then sounds like it is firing too soon, and the engine tries to start backwards. Maybe my timing settings are way off for a cold engine? I dunno, having a hard time with this one.

Video: http://www.youtube.com/watch?v=jsim-QGKWaA

MSQ : http://twardnw.com/d/8593-1/2010-02-14_12_29_02.msq

Log : http://twardnw.com/d/8605-1/2010-02-14_12_31_08.msl

log isn't from the same attempt that I recorded, but the result is the same.

This has only started happening since I switched over to controlling ignition. Ran the car for over a year with only fuel control with no issues. I have verified the static timing of the engine is correct (Crank, dizzy, cam).

Re: difficulty starting

Posted: Mon Feb 15, 2010 6:36 am
by Matt Cramer
It does sound like your timing's off. Have you checked it with a timing light?

Re: difficulty starting

Posted: Mon Feb 15, 2010 8:36 am
by twardnw
not while cranking, but I don't even know what it should be set at.

Re: difficulty starting

Posted: Mon Feb 15, 2010 10:37 am
by Matt Cramer
Most engines would crank best in the 0-20 degrees BTDC range.

Re: difficulty starting

Posted: Mon Feb 15, 2010 11:04 am
by twardnw
I've been researching this a bit on my own too, and it appears that the person I borrowed the ignition settings from was mis-informed. I have had the base angle set at 6*, but after some more reading, it should be closer to 60.

Re: difficulty starting

Posted: Mon Feb 15, 2010 6:20 pm
by twardnw
Ok, changed the trigger angle to 60*, and it started nice and easy, once. Then, it went back to a couple cranks, and then stall, just like in the video.

I got a timing light on it, made a switch to run the starter, and tried it. A moment of cranking, and then one spark, don't know exactly what angle it was at, but as soon as it did, the engine stops dead (exactly like the video).

Re: difficulty starting

Posted: Tue Feb 16, 2010 6:07 am
by Matt Cramer
Are you seeing RPM while cranking?

Re: difficulty starting

Posted: Tue Feb 16, 2010 12:55 pm
by twardnw
The log shows it is, didn't pay attention to TunerStudio while it was cranking, just had it recording the datalog.

Re: difficulty starting

Posted: Tue Feb 16, 2010 11:30 pm
by john.p.clegg
Try taking the plugs out and disconnect the injectors,then you can spin the engine over and over and check the timing without it trying to fire..
John :)

Re: difficulty starting

Posted: Fri Feb 19, 2010 5:46 pm
by twardnw
ok, so I have the injectors disconnected now, and can crank it over with my home-brew starter switch, don't know exactly where the timing is yet, but as soon as the batter charges a little more, I should be able to figure it out. Then what? :mrgreen:

Re: difficulty starting

Posted: Sat Feb 20, 2010 12:03 pm
by grippo
If the timing is correct while cranking, then look at whether you selected trigger rise or calculated for the crank trigger. If you selected calculated and the timing light matches the advance gauge in TS/MT, then you should be good everywhere. If it isn't correct, then change the trigger offset (under basic ignition) until it does match. If you selected trigger rise then the timing you will see is the location of the engine when the ECU gets a tach pulse, because in trigger rise, while cranking. the ECU will spark exactly on a tach pulse. If this timing is some inappropriate value like 40 deg btdc, then you need to either select calculated and change trigger offset or move the dizzy to get a more reasonable cranking timing like 10 deg btdc.

Re: difficulty starting

Posted: Sun Feb 21, 2010 10:43 am
by twardnw
so if I set the trigger angle to 0, and have it using trigger rise (even though the trigger capture is on falling edge?), and line the dizzy up exactly with the TDC mark, everything should spark on 0, correct?

Re: difficulty starting

Posted: Sun Feb 21, 2010 3:34 pm
by twardnw
Ok, so with randomly changing the trigger angle, I finally got it to start, and stay running, found my trigger angle to be ~30*. Should I do something to try and adjust that back closer to 'normal'? I think my idle advance should be 10-15, so would that be a good region to have my trigger angle in?

Also, trying to measure the amount of advance with my timing light. The light I am using only has a dial to adjust the amount of advance. When idling, I was able to match the strobe w/ 0* by cranking the dial to ~45*. So would that be 45* - trigger angle (30ish) = 15*?