cold start vs. Hot start
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Senior User
Joined: Apr 2004
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cold start vs. Hot start
95 4L AWD
Real hard to start after a warm restart. Like, engine up to temp. Turn off for 5 minutes. Then go to restart. Takes a while to start. then acts like its flooded. Blip the throttle a couple times and it clears and idle smooths out.
20 degree cold start. Takes half as long to start and starts with a smooth idle.
Real hard to start after a warm restart. Like, engine up to temp. Turn off for 5 minutes. Then go to restart. Takes a while to start. then acts like its flooded. Blip the throttle a couple times and it clears and idle smooths out.
20 degree cold start. Takes half as long to start and starts with a smooth idle.
Post Fiend
Joined: Apr 2005
Posts: 5,720
Likes: 5
From: Washington state
any codes?
do you start with no throttle action by driver? mandatory with these ECU/PCM controlled vehicles.
likely culprits.
failed ECT or wiring.
failed IAT or wiring.
http://fordfuelinjection.com/?p=28
when was the MAF cleaned or replaced last?
do you start with no throttle action by driver? mandatory with these ECU/PCM controlled vehicles.
likely culprits.
failed ECT or wiring.
failed IAT or wiring.
http://fordfuelinjection.com/?p=28
when was the MAF cleaned or replaced last?
Elder User
Joined: Dec 2006
Posts: 830
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From: Kitchener,Ontario,Canada
Too much fuel?
95 4L AWD
Real hard to start after a warm restart. Like, engine up to temp. Turn off for 5 minutes. Then go to restart. Takes a while to start. then acts like its flooded. Blip the throttle a couple times and it clears and idle smooths out.
20 degree cold start. Takes half as long to start and starts with a smooth idle.
Real hard to start after a warm restart. Like, engine up to temp. Turn off for 5 minutes. Then go to restart. Takes a while to start. then acts like its flooded. Blip the throttle a couple times and it clears and idle smooths out.
20 degree cold start. Takes half as long to start and starts with a smooth idle.
If pressure will not hold with KOEO, suspect leaking injector or other fuel pressure leak. Leaking injector would hardly be noticable at cold start, but at hot start it will def cause some problems.
Air filter blocked or faulty ECT or ACT could cause this condition also.
Any black smoke out the tailpipe?
Lead Driver
Joined: Sep 2003
Posts: 7,013
Likes: 205
From: SoCal
Funny, my van just started to exhibit similar symptoms. But more specifically, it's gotten much easier to start when it's been off for a long time, like a week, but warm start has not changed. It used to take at least a second of cranking to start whether warm or cold. Now, after sitting for a few days, it starts within the first half second of cranking. When warm, it goes to normal again. I'm also wondering if the injectors have a small leak that pools fuel over time, which makes the cold starts seem too easy.
Elder User
Joined: Dec 2006
Posts: 830
Likes: 0
From: Kitchener,Ontario,Canada
Funny, my van just started to exhibit similar symptoms. But more specifically, it's gotten much easier to start when it's been off for a long time, like a week, but warm start has not changed. It used to take at least a second of cranking to start whether warm or cold. Now, after sitting for a few days, it starts within the first half second of cranking. When warm, it goes to normal again. I'm also wondering if the injectors have a small leak that pools fuel over time, which makes the cold starts seem too easy.
Ford engine strategy allows 1 second of NO spark at cold crank to prime the oil system & build up pressure. Big help with engine longevity.
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Lead Driver
Joined: May 2003
Posts: 9,303
Likes: 48
From: Lyndonville, Vermont
I would check coolant temp sensor and air charge sensor for correct resistance...If you have two or more injectors leaking you may have a hard time starting. I have one leaky injector from time to time but never hard start..I did have hard start on a 94 and 96 both cases it was the fuel pump...
Dick
Dick
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Joe Kucinski
Senior User
Joined: Jan 2008
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I had trouble starting my Aerostar when the engine was warm. My CHECK ENGINE light was on and after taking it to a shop to check the code for the CHECK ENGINE it turns out it was my coolant temp sensor. I changed that and starts up after 3 cranks no matter what the temp is. Its cheap and easy to change, I would just change it because its a simple fix.
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Senior User
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Sorry I've been busy. I tested the regulator last year.
I was thinking the ECT myself. On my old 914's they have a cold start valve that is a 5th injector to give it extra fuel when cold. The Aerostar acts the same as the 914 did when it started leaking.
No codes. New fuel pump. Where/how do I hook up a fuel pressure gauge ?
I was thinking the ECT myself. On my old 914's they have a cold start valve that is a 5th injector to give it extra fuel when cold. The Aerostar acts the same as the 914 did when it started leaking.
No codes. New fuel pump. Where/how do I hook up a fuel pressure gauge ?
Post Fiend
Joined: Apr 2005
Posts: 5,720
Likes: 5
From: Washington state
on the passenger side on fuel rail, there is a connector that looks like a tire air stem. Schrader valve. fuel pressure gauge hose screws onto it. be careful and drain first with shop rag over top of hand and valve to keep gas spray out of eyes.
should see 30 psi minimum at idle, 35 psi at 2k rpm.
shut off engine and should not drop more than 5 psi in an hour.
pull off and look for fuel drips and and breaks or deterioration in the FP regulator vacuum line
should see 30 psi minimum at idle, 35 psi at 2k rpm.
shut off engine and should not drop more than 5 psi in an hour.
pull off and look for fuel drips and and breaks or deterioration in the FP regulator vacuum line