Hot Start Issues

[styxplo]

Im using Tunerstudio MS lite v2.08. Im also using megasquirt-II _2920.ini, Monitor_v2.920.abs.s19 I have a ford v6 171 with throttle body injection. I now have it running better then it ever did with a carb and I think I have my VE table fairly tuned in. My problem is that It starts right up from a cold start on the first crank. If I drive it and warm it up (above 190 dgrees) then shut it off. I can't get it to start at all. It will crank until the battery dies. If it sits for a half hour or so it will fire right up again. I'm just wondering if someone else can catch something in my tune that I'm not. How long shoud the fuel pressure stay before it drops off after shutdown?? I have attached my current tune.

[Matt Cramer]

Can you capture the hot start issue in a data log? This will give me more to go on.

Note that I find using tables for cranking pulse width to make it easier to tune than two point mode.

[styxplo]

The cranking pulse has definetly given me the most trouble. Here are the data logs. One is a cold start and the other a hot start. It actually started hot this time after cranking for a while which is unusual, but I just let it idle in my driveway to heat it up.

[Matt Cramer]

Try adjusting the upper cranking pulse width setting.

[styxplo]

I've adjusted it many times with no success. Do u recommend raising or lowering it

[Matt Cramer]

Next time it won't start, try pulling a spark plug and see if it's wet with fuel or dry. If it's dry, raise your cranking pulse width; if it's wet, lower it.

[styxplo]

You mentioned that you like using cranking pulse tables instead of 2 point. I can't find the option to use tables. The laptop I have doesnt connect to the internet so I can't use the tunerstudio help to look it up. Thanks

[Matt Cramer]

It's under Fuel Set-up -> General. Under "Prime, ASE, WUE, & Baro Tables", switch from "Two point" to "use table".

[styxplo]

I tried that and nothing changed. Will the table still be found under the tuning tab- warm up

[Matt Cramer]

The cranking pulse will be under Other Tables.

[styxplo]

It's still located on the warm up enrichment table page, but it is still 2 point ( I believe 1 at -40 and 1 at 160ish) not multi-point

[Matt Cramer]

The 2 points in the WUE page are now ignored and it will use the curve instead.

[Blown88GT]

Im using Tunerstudio MS lite v2.08. Im also using megasquirt-II _2920.ini, Monitor_v2.920.abs.s19 I have a ford v6 171 with throttle body injection. I now have it running better then it ever did with a carb and I think I have my VE table fairly tuned in. My problem is that It starts right up from a cold start on the first crank. If I drive it and warm it up (above 190 dgrees) then shut it off. I can't get it to start at all. It will crank until the battery dies. If it sits for a half hour or so it will fire right up again. I'm just wondering if someone else can catch something in my tune that I'm not. How long shoud the fuel pressure stay before it drops off after shutdown?? I have attached my current tune.

Your tune looks OK. Fuel pressure should remain for a couple hours after shutdown; it will slowly bleed off. If no pressure when you try to hot start, it will flood. Put pedal to floor will override flood & it will start, but will make lots of soot.

[styxplo]

To tune the cranking pulse using the curve I'm expecting to see something that looks like the warm up enrichment table. I still cant find anything like that for the crankIng pulse settings.

[Blown88GT]

To tune the cranking pulse using the curve I'm expecting to see something that looks like the warm up enrichment table. I still cant find anything like that for the crankIng pulse settings.

it called Cranking Pulse %. Looks the same to me.

[styxplo]

Sorry if I'm making this harder then it seems. I still don't see the option. Under what tab is it located.

[Matt Cramer]

It will be under the Other Tables tab.