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Trouble starting when engine is warm
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New User
Joined: Jan 2008
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Trouble starting when engine is warm
Have a 1996 Ford F-150. Starts fine when engine is cold. When engine is warm, it sputters (often severely), and stalls before finally starting. Have to press accelerator before truck will start. Replaced fuel filter, did not help. Could it be related to crank shaft? Any ideas appreciated!
Postmaster
Joined: Oct 2006
Posts: 4,816
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From: Davis & Newcastle, CA
Originally Posted by danr1
Sounds like a sensor problem that kicks in once it goes closed loop, pull the codes and see what that tells you.
Lead Driver
Joined: Aug 2006
Posts: 5,670
Likes: 13
From: Sand Lake, MI
Originally Posted by Skandocious
Aren't sensors always on open loop for at least the first couple seconds after startup, no matter how warm or cold? His problem is happening ON startup, not after the truck has been running for a while.
Scroll down to the chart on this page, shows what sensors comes into play and when as the engine heats up.
http://www.fordfuelinjection.com/?p=3
Being as it starts fine when cold but not once it is warmed up it would lead one to believe it is a sensor failing that is read by the computer once the system goes closed loop but is not used when it is cold.
That is what I'd start with anyway.
Postmaster
Joined: Oct 2006
Posts: 4,816
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From: Davis & Newcastle, CA
Originally Posted by danr1
Nope, not all of them.
Scroll down to the chart on this page, shows what sensors comes into play and when as the engine heats up.
http://www.fordfuelinjection.com/?p=3
Being as it starts fine when cold but not once it is warmed up it would lead one to believe it is a sensor failing that is read by the computer once the system goes closed loop but is not used when it is cold.
That is what I'd start with anyway.
Scroll down to the chart on this page, shows what sensors comes into play and when as the engine heats up.
http://www.fordfuelinjection.com/?p=3
Being as it starts fine when cold but not once it is warmed up it would lead one to believe it is a sensor failing that is read by the computer once the system goes closed loop but is not used when it is cold.
That is what I'd start with anyway.
Lead Driver
Joined: Aug 2006
Posts: 5,670
Likes: 13
From: Sand Lake, MI
Originally Posted by Skandocious
That page shows that any start/crank situation calls for open loop...
Yes but being as engine temp seams to have a lot to do with the problem I'd still pull the codes and see if it has any and if so what they are.
<i>When engine is warm, it sputters (often severely), and stalls before finally starting.</i>
How can it sputter and <u>stall</u> if it hasn't started to begin with? If it stalls it must have started, if it starts runs and is warm it goes closed loop instantly.
Just "guessing" by going on the little bit of information given.
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Postmaster
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From: Davis & Newcastle, CA
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Lead Driver
Joined: Aug 2006
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From: Sand Lake, MI
Originally Posted by Skandocious
Yeah I suppose you're right. Sorry I'm not arguing with you Dan, this is just a discussion 
Yea I might be wrong too, just where I'd start and then go from there.
And as you know, it may not even give any codes to go on.
Lead Driver
Joined: Aug 2006
Posts: 5,670
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From: Sand Lake, MI
"OT" warning,
I'm looking at a 96 f250 tomorrow, think I can get it cheap 7, 8 hundred bucks. The guy already agreed on the phone to 8 but I think I can get it down a tad more. Runs good and everything works but has a broken axle housing up front. Big deal to the owner but not to me, easy fix just takes a little time.
Looked it over good today but we'll meet at it so I can hear it run and drive it around a little to listen for and "bad" sounds. I've seen it around and it had been driven daily until about a week ago. The guy lives in one of the apartment complexes I plow and when I noticed it was gone I asked about it. Turns out it just around the corner at at tire shop.
Be kinda nice to have the OBD2 system on a truck too so I can use my laptop on it like I do on the wifes car.
Has the 5.8, E40D manual 4 wheel and is the heavy duty version.
Anyway back to your regularly scheduled thread!
I'm looking at a 96 f250 tomorrow, think I can get it cheap 7, 8 hundred bucks. The guy already agreed on the phone to 8 but I think I can get it down a tad more. Runs good and everything works but has a broken axle housing up front. Big deal to the owner but not to me, easy fix just takes a little time.
Looked it over good today but we'll meet at it so I can hear it run and drive it around a little to listen for and "bad" sounds. I've seen it around and it had been driven daily until about a week ago. The guy lives in one of the apartment complexes I plow and when I noticed it was gone I asked about it. Turns out it just around the corner at at tire shop.
Be kinda nice to have the OBD2 system on a truck too so I can use my laptop on it like I do on the wifes car.
Has the 5.8, E40D manual 4 wheel and is the heavy duty version.
Anyway back to your regularly scheduled thread!
New User
Joined: Jan 2008
Posts: 3
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From: pontiac,mi
I have a rough 94 F250 plow truck and just traded a 90 F150 heavily modified- 12" lift 40" groundhawgs, Detroit's front and rear w/ 4.88's - both with 5.8L's, auto trans and 4wd and as we changed out the 5.0 in the 90 to the 5.8, we had the timing off and after it was warm it felt like it was going to rip the truck apart while cranking, turned the distributor just a little and everything worked out.
Also all my work trucks got messed with winter before last - salt in the tanks, plug wires pulled, generally screwed with, a long story- anyway after we put the trucks back together the F250 started to do the same thing, also only when warm, and sure enough timing was just a little off, turned out the distributor bolt was loose on it and it walked around a little.
BTW salt eats the impellers out of the fuel pumps and screws with the fuel pressure slowly or all at once - a little of both in my case
94 F250 4x4, 95 PSD F250 4x4, 85 F700 w/ Detroit, 97 F700 429, 99 F550 V10 and the oddball 87 1/2 ton Chevy plow truck
Also all my work trucks got messed with winter before last - salt in the tanks, plug wires pulled, generally screwed with, a long story- anyway after we put the trucks back together the F250 started to do the same thing, also only when warm, and sure enough timing was just a little off, turned out the distributor bolt was loose on it and it walked around a little.
BTW salt eats the impellers out of the fuel pumps and screws with the fuel pressure slowly or all at once - a little of both in my case
94 F250 4x4, 95 PSD F250 4x4, 85 F700 w/ Detroit, 97 F700 429, 99 F550 V10 and the oddball 87 1/2 ton Chevy plow truck
Cargo Master
Joined: Apr 2003
Posts: 3,476
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From: Frequently frozen MN
Just some thoughts ( on topic) -- I'm certainly no expert
1. Some kind of vapor lock -- I know its FI, but maybe the fuel pump is having some issues
2. Problem with the CTS -- the engine is in open loop, but the computer still uses the fuel map to detemine the injector pulse length. It uses the temp as part of this
3. A little injector leak -- something that might evaporate by the time it gets cold.
ford2go
1. Some kind of vapor lock -- I know its FI, but maybe the fuel pump is having some issues
2. Problem with the CTS -- the engine is in open loop, but the computer still uses the fuel map to detemine the injector pulse length. It uses the temp as part of this
3. A little injector leak -- something that might evaporate by the time it gets cold.
ford2go
Senior User
Joined: Nov 2006
Posts: 418
Likes: 0
From: Quad Cities, IA
Originally Posted by ford2go
Just some thoughts ( on topic) -- I'm certainly no expert
1. Some kind of vapor lock -- I know its FI, but maybe the fuel pump is having some issues
2. Problem with the CTS -- the engine is in open loop, but the computer still uses the fuel map to detemine the injector pulse length. It uses the temp as part of this
3. A little injector leak -- something that might evaporate by the time it gets cold.
ford2go
1. Some kind of vapor lock -- I know its FI, but maybe the fuel pump is having some issues
2. Problem with the CTS -- the engine is in open loop, but the computer still uses the fuel map to detemine the injector pulse length. It uses the temp as part of this
3. A little injector leak -- something that might evaporate by the time it gets cold.
ford2go
Since it's an old beater, I haven't been too concerned with it, though it'd be nice to track it down and fix someday.
Fleet Owner
Joined: Aug 2005
Posts: 23,667
Likes: 301
From: Easton,Ks
Originally Posted by danr1
"OT" warning,
Be kinda nice to have the OBD2 system on a truck too so I can use my laptop on it like I do on the wifes car.
Has the 5.8, E40D manual 4 wheel and is the heavy duty version.
Be kinda nice to have the OBD2 system on a truck too so I can use my laptop on it like I do on the wifes car.
Has the 5.8, E40D manual 4 wheel and is the heavy duty version.