Need help with starting issues

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masterflight
MS/Extra Newbie
Posts: 15
Joined: Mon Jun 13, 2011 8:44 pm

Need help with starting issues

Post by masterflight »

Hi all,

MSQ is attached. No problems with signals or sensors. I just can't seem to figure out how to tune prime/crank/ASE/WUE...

MS3, 3X (3.54)

Project is a 1995 Chevy Cavalier. 2.2 liter OHV 4 cylinder. All stock except for a real cold air box with K&N cone filter, OBX 4/2/1 header with Flowmaster 40/generic Catcon.
I'm using LS2 truck coils. Manual trans. Sequential fueling of stock injectors. 36-1 wheel

In case you're wondering why someone would put all this MS stuff on a car that's not worth as much as the MS... a LS4 will bolt right up to the stock trans. 300 hp; 325 #ft !!

When it's cold it cranks 5 times longer than it should and I have to pump the throttle 3-4 times, then go full throttle for a second and then slowly return toward idle. It usually starts but then I have to pump the throttle to get it to run cleanly. After 30 seconds I can let it to idle and all is well.

Warm restarts are better but not good compared to the factory ECU. It starts, runs for a few seconds and dies, with the second crank attempt doing nothing. On the third try it starts and runs normally.

Thanks to all for the help. I'd like to make it to the meet on Sat but have to work.

Dennis
kjones6039
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Location: Eureka, NV USA
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Re: Need help with starting issues

Post by kjones6039 »

A log fie to go along with your msq would be very helpful...........,

Ken
1979 Corvette - 383 CID SBC w/ Holley Pro-Jection 900 CFM TBI, 4-85 lb lo-z injectors & Walbro 255 pump
MS2 v3 w/extra 3.4.2 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
TinyIOX from JBPerformance
kaeman
Master MS/Extra'er
Posts: 643
Joined: Sun Nov 06, 2005 12:31 am
Location: NORTHERN CALIFORNIA

Re: Need help with starting issues

Post by kaeman »

a couple of things I noticed, your injector dead time is 1.3ms, that seems like a long time.. my injectors dead time are .6ms, and some of my injector sets have dead times of .35ms... but I have never tested a set that was more than 1.0ms.
in your ego/o2 set up you have the corrections above 17 and below 13.5, your sensor isn't being allowed to correct for any of the values in your afr table. it can only correct values from 17 to 22 and 13.5 to 8. and these values are not in your afr target table. if you want it to make corrections in the tables ranges, then the above limit needs to be 9 or 10 and the below limit needs to be 17 or 18..
this will allow your ego corrections to happen when you want them.

also your cranking pulsewidths seem kinda high, if your port injected and not throttle body injected you are not loosing a lot of fuel in the way to the cylinder, so you don't need the large fuel pulsewidth during cranking. you're likely flooding the engine and that is why pumping the throttle helps it fire up.

I would cut the cranking pulsewidth values in half, and any values above 140 degrees coolant should be set to 100% and try that... see if that helps. remember those values are a % of the required fuel so 150 is i.5 times the required fuel... and 100 is the actual required fuel.

good luck.
64 el camino, 383 SBC, 11.7 to1 CR, accufab tb/rhs intake, 44lb injectors, trick flow heads, xr292r solid roller cam, belt drive camshaft, dry sump oil system, 2400 stall, turbo 350, spooled 9 inch, strange axles, 3.89 gears, dual wideband, full sequential fuel/cop, MS3x using 1.4.1 code.
masterflight
MS/Extra Newbie
Posts: 15
Joined: Mon Jun 13, 2011 8:44 pm

Re: Need help with starting issues

Post by masterflight »

Please forgive my extremely tardy reply. I missed it...must need new glasses.

Thanks for your input. I will adjust and report back.

Dennis
kaeman wrote:a couple of things I noticed, your injector dead time is 1.3ms, that seems like a long time.. my injectors dead time are .6ms, and some of my injector sets have dead times of .35ms... but I have never tested a set that was more than 1.0ms.
in your ego/o2 set up you have the corrections above 17 and below 13.5, your sensor isn't being allowed to correct for any of the values in your afr table. it can only correct values from 17 to 22 and 13.5 to 8. and these values are not in your afr target table. if you want it to make corrections in the tables ranges, then the above limit needs to be 9 or 10 and the below limit needs to be 17 or 18..
this will allow your ego corrections to happen when you want them.

also your cranking pulsewidths seem kinda high, if your port injected and not throttle body injected you are not loosing a lot of fuel in the way to the cylinder, so you don't need the large fuel pulsewidth during cranking. you're likely flooding the engine and that is why pumping the throttle helps it fire up.

I would cut the cranking pulsewidth values in half, and any values above 140 degrees coolant should be set to 100% and try that... see if that helps. remember those values are a % of the required fuel so 150 is i.5 times the required fuel... and 100 is the actual required fuel.

good luck.
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