Hard to start truck after engine is warm
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Joined: Aug 2019
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From: Litchfield
Hard to start truck after engine is warm
2004 Ford Ranger XTL V6 3.0 210k miles - When the engine is cold, the truck starts right up no issues. After I've driven for a bit and park it (like go into the grocery store), it takes a good amount of cranking before the engine will turn over. It takes so long I can tell the battery gets weaker as I'm cranking the engine to get it started. It always starts, but takes time and I cannot figure out what's causing it. The idle is a bit rough after this happens and bounced +/- 50 around 750RPM, but no stalling.
Plugs, wires, and coils are all relatively new and in good condition.
Air filter is new.
PCV valve is brand new (a bad PCV valve was causing the truck to stall at idle and throwing codes: P0171, P0174, P0300, & P0316 and replacing it fixed those issues)
The battery is a bit old and needing replaced, could this cause the engine to take along time to start after it's warm? It cranks right up when cold though
My other thoughts are:
Clean the MAF
Run a can of seafoam through it
I did the Clear Flooded Engine Test recommended by RonD and the engine turns over even with the pedal pushed all the way to the ground so I'm thinking maybe there's too much fuel in the intake? Not sure how to begin diagnosing that or if that's causing the hard start when warm.
Any tips are appreciated!
Plugs, wires, and coils are all relatively new and in good condition.
Air filter is new.
PCV valve is brand new (a bad PCV valve was causing the truck to stall at idle and throwing codes: P0171, P0174, P0300, & P0316 and replacing it fixed those issues)
The battery is a bit old and needing replaced, could this cause the engine to take along time to start after it's warm? It cranks right up when cold though
My other thoughts are:
Clean the MAF
Run a can of seafoam through it
I did the Clear Flooded Engine Test recommended by RonD and the engine turns over even with the pedal pushed all the way to the ground so I'm thinking maybe there's too much fuel in the intake? Not sure how to begin diagnosing that or if that's causing the hard start when warm.
Any tips are appreciated!
Watch the CEL(check engine light)
It should come on with key on and stay on, that means computer has booted up
Try to start engine
As soon as engine starts to turn the CEL should go OFF, that means computer is getting a Timing Pulse from Crank sensor, no pulse = no start, and CEL stays on
After engine is warmed up and off, take the air tube off the intake and open throttle manually and see if you smell gasoline, you shouldn't
When you shut off a fuel injected engine the injectors turn off instantly but engine RPMs continue and slow down to 0
So this would eliminate any gasoline smell in the intake
If there is a smell then an injector is leaking fuel in
For now USE the Clear Flooded Engine routine to start warm engine, that's the point of having it in the computer, just for situations like this, see if it helps
The wide open throttle drys out the "flooded engine" while cranking engine over
It should come on with key on and stay on, that means computer has booted up
Try to start engine
As soon as engine starts to turn the CEL should go OFF, that means computer is getting a Timing Pulse from Crank sensor, no pulse = no start, and CEL stays on
After engine is warmed up and off, take the air tube off the intake and open throttle manually and see if you smell gasoline, you shouldn't
When you shut off a fuel injected engine the injectors turn off instantly but engine RPMs continue and slow down to 0
So this would eliminate any gasoline smell in the intake
If there is a smell then an injector is leaking fuel in
For now USE the Clear Flooded Engine routine to start warm engine, that's the point of having it in the computer, just for situations like this, see if it helps
The wide open throttle drys out the "flooded engine" while cranking engine over
Thread Starter
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Joined: Aug 2019
Posts: 8
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From: Litchfield
Watch the CEL(check engine light)
It should come on with key on and stay on, that means computer has booted up
Try to start engine
As soon as engine starts to turn the CEL should go OFF, that means computer is getting a Timing Pulse from Crank sensor, no pulse = no start, and CEL stays on
After engine is warmed up and off, take the air tube off the intake and open throttle manually and see if you smell gasoline, you shouldn't
When you shut off a fuel injected engine the injectors turn off instantly but engine RPMs continue and slow down to 0
So this would eliminate any gasoline smell in the intake
If there is a smell then an injector is leaking fuel in
For now USE the Clear Flooded Engine routine to start warm engine, that's the point of having it in the computer, just for situations like this, see if it helps
The wide open throttle drys out the "flooded engine" while cranking engine over
It should come on with key on and stay on, that means computer has booted up
Try to start engine
As soon as engine starts to turn the CEL should go OFF, that means computer is getting a Timing Pulse from Crank sensor, no pulse = no start, and CEL stays on
After engine is warmed up and off, take the air tube off the intake and open throttle manually and see if you smell gasoline, you shouldn't
When you shut off a fuel injected engine the injectors turn off instantly but engine RPMs continue and slow down to 0
So this would eliminate any gasoline smell in the intake
If there is a smell then an injector is leaking fuel in
For now USE the Clear Flooded Engine routine to start warm engine, that's the point of having it in the computer, just for situations like this, see if it helps
The wide open throttle drys out the "flooded engine" while cranking engine over
If the injector is leaking fuel, could it also be causing the lean codes?
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From: Litchfield
What's the best way to check for an intake manifold leak? Is this also a vacuum leak? Before I replaced the PCV valve I was getting lean codes (both banks) along with random misfires. Replacing the PCV valve fixed the constant misfire codes (mostly misfiring at idle), but not the lean codes.
I'll have to check for low fuel pressure as well.
Thanks!
I'll have to check for low fuel pressure as well.
Thanks!
After engine is warmed up and idling, unplug the 2 wire connector on IAC Valve
If idle drops down or engine stalls then there is no "air leak", the computer was setting the high idle
If idle does not change then you have an "air leak" or a stuck IAC Valve
If idle drops down or engine stalls then there is no "air leak", the computer was setting the high idle
If idle does not change then you have an "air leak" or a stuck IAC Valve
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From: Litchfield
Pulled the connector off the IAC valve and engine dropped to ~500 rpm and even misfired. So now I'm seeing the two lean codes with misfire codes: P0300 and P0304. Any thoughts?
So you don't have a vacuum leak, that's good
P300 or P316 mean random or cold start misfires
P0306 means cylinder 6 has a steady misfire
The Lean codes are CAUSED by the misfires, so when misfires are fixed Lean codes will go away
Have a look at the tips of spark plugs 5 and 6, 5 is for a reference, 6 because thats the cylinder with the issue
If 6 looks OK swap 5 to 6 and 6 to 5 and see if you start to get P0305
How old are the O2 sensors?
They only last 12 years, or 100k miles, which ever comes first
Google: Ford Ranger throttle cable mod
Just need a zap-strap to fix stretched throttle cable so you can re-try the Clear Flooded engine test, also get full throttle back
2004 to 2006 3.0l Ranger engines can get recessed exhaust valve seats, there was a TSB for it, here: https://www.therangerstation.com/for...n-tsb-05-26-3/
Unfortunately yours falls in that range
Had to replace both heads to fix it
Symptoms are misfires
Need to do a compression test to take that off the table
P300 or P316 mean random or cold start misfires
P0306 means cylinder 6 has a steady misfire
The Lean codes are CAUSED by the misfires, so when misfires are fixed Lean codes will go away
Have a look at the tips of spark plugs 5 and 6, 5 is for a reference, 6 because thats the cylinder with the issue
If 6 looks OK swap 5 to 6 and 6 to 5 and see if you start to get P0305
How old are the O2 sensors?
They only last 12 years, or 100k miles, which ever comes first
Google: Ford Ranger throttle cable mod
Just need a zap-strap to fix stretched throttle cable so you can re-try the Clear Flooded engine test, also get full throttle back
2004 to 2006 3.0l Ranger engines can get recessed exhaust valve seats, there was a TSB for it, here: https://www.therangerstation.com/for...n-tsb-05-26-3/
Unfortunately yours falls in that range
Had to replace both heads to fix it
Symptoms are misfires
Need to do a compression test to take that off the table
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