Hard Start
08-24-2009, 06:31 PM
#1
Thread Starter
Join Date: Oct 2008
Location: NY
Posts: 33
Hard Start
on my 2003 gt, sometimes when i start my car is doesnt start after the engine becomes hot, the engine would turn over but doesnt turn on, i have a new optima battery in it, what should i check, the car has 73k miles i thought it could be the starter, but my cold starts are fine
08-24-2009, 08:29 PM
#3
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
Hot start issues are somewhat common with the 2V 4.6.
I had found that by flooring the accelerator the car would start, so going on the premise that it was flooding I leaned out the Cranking AFR function (which maps ECT against AFR while cranking) using Delta Force Commando. The OEM setting at 200°F+ ECT was 13.8:1, I dropped it to 13.2:1 and the problem mostly went away--I may drop it a couple tenths more on the next tune.
I had found that by flooring the accelerator the car would start, so going on the premise that it was flooding I leaned out the Cranking AFR function (which maps ECT against AFR while cranking) using Delta Force Commando. The OEM setting at 200°F+ ECT was 13.8:1, I dropped it to 13.2:1 and the problem mostly went away--I may drop it a couple tenths more on the next tune.
08-24-2009, 09:42 PM
#7
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
The OEM plugs are scheduled to be changed at 100k miles, however doing it now won't hurt.
One thing I found before altering the tune was that if, when hot, I cranked it a bit longer than "normal" it would start. I think the brief stop, hot soak, is coaxing fuel from the injectors and flooding the engine--cranking just a tiny bit longer than seems right lets it clear...
One thing I found before altering the tune was that if, when hot, I cranked it a bit longer than "normal" it would start. I think the brief stop, hot soak, is coaxing fuel from the injectors and flooding the engine--cranking just a tiny bit longer than seems right lets it clear...
08-25-2009, 09:24 PM
#8
4th Gear Member
Join Date: Aug 2007
Location: Delawere
Posts: 1,334
i too had this problem after upgrading the injectors and everything for the blower.
I had to give it some gas to get it started.
My tuner said something about injector pulse width at start up...he changed something in my tune and it fires right up everytime when its hot now.
I had to give it some gas to get it started.
My tuner said something about injector pulse width at start up...he changed something in my tune and it fires right up everytime when its hot now.
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Dragonus18
4.6L (1996-2004 Modular) Mustang
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