Starting issues, 4.0L
Thread Starter
|
Cross-Country
Joined: Feb 2010
Posts: 67
Likes: 1
Starting issues, 4.0L
Ok in another thread if you didnt read it, we just the other day finished putting in new upper and lower intake gaskets in, along with the fuel rail gasket and the new injector O rings.
Everything seemed fine for a dozen startups until today.
Here is the Situation; From a cold start, half the time it fires right up, BUT the other half of the time you turn it over and it barely starts up, acting as if its running out of gas. Pushing the gas pedal at this point does nothing, it will shake and blubber and then stall.
Now, this will often happen the 1st and 2nd time you try to start it. The on the 3rd or 4th try it fires right up and runs fine.
You can drive it all day under any conditions, it runs perfectly. Idles just fine. But when you shut it off you have a 50/50 chance it will do the suspicious thing.
Well for a few tries and then your on your way as if nothing is wrong with it.
My suspicion is the fuel is not getting up to pressure that first couple times for some oddball reason, But... why it only does it half the time, I have no clue. Youd think with a fuel pressure issue it wouldn't run right under load or any other time.
No codes, no pending codes. No smoke, no noises, nothing at all out of the ordinary.
Any suggestion to where to look first?
Everything seemed fine for a dozen startups until today.
Here is the Situation; From a cold start, half the time it fires right up, BUT the other half of the time you turn it over and it barely starts up, acting as if its running out of gas. Pushing the gas pedal at this point does nothing, it will shake and blubber and then stall.
Now, this will often happen the 1st and 2nd time you try to start it. The on the 3rd or 4th try it fires right up and runs fine.
You can drive it all day under any conditions, it runs perfectly. Idles just fine. But when you shut it off you have a 50/50 chance it will do the suspicious thing.
Well for a few tries and then your on your way as if nothing is wrong with it.
My suspicion is the fuel is not getting up to pressure that first couple times for some oddball reason, But... why it only does it half the time, I have no clue. Youd think with a fuel pressure issue it wouldn't run right under load or any other time.
No codes, no pending codes. No smoke, no noises, nothing at all out of the ordinary.
Any suggestion to where to look first?
Post Fiend
Joined: Jan 2003
Posts: 9,748
Likes: 16
From: Connecticut
Youd think with a fuel pressure issue it wouldn't run right under load or any other time.
I think a fuel pressure test is probably the next logical step (performed at the same time you are having the starting problem would be ideal).
Senior User
Joined: Feb 2005
Posts: 294
Likes: 0
From: Tillamook, Or.
Just a Couple Questions
Have you checked all the simple Stuff?
Recent fuel filter?
Are you sure about the condition of the fuel pump?
My 2000 XLT did this until I replaced the Fuel pump. Then it all went away.
Recent fuel filter?
Are you sure about the condition of the fuel pump?
My 2000 XLT did this until I replaced the Fuel pump. Then it all went away.
Thread Starter
|
Cross-Country
Joined: Feb 2010
Posts: 67
Likes: 1
I got a p0153 code today so maybe replacing those weak O2 sensors will do it. I'll do a new fuel filter while I'm at it.
Trending Topics
Thread Starter
|
Cross-Country
Joined: Feb 2010
Posts: 67
Likes: 1
Now when it does that spit and sputter act I get a p0303 misfire pending. But it smooths out and doesn't throw the code.
Parts are in the mail.... *sigh*
Parts are in the mail.... *sigh*
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Thread Starter
|
Cross-Country
Joined: Feb 2010
Posts: 67
Likes: 1
Amazon prime is quick...
The new o2sensors are in, and the computer was cleared.
I started it up it did the same thing, rough idle for about 10 seconds then it smoothed out and idled fine.
It began to pour down rain so I havent driven it yet. Tomorrow it will get a lot of driving.
I was thinking, these injectors are as old as the truck. Could it be that an injector is leaking off the fuel pressure when its turned off, and flooding one cyl? This would explain the nature of the problem, as soon as the gas clears out of the cyl all is well.
If I continue to get a misfire pending code on #3 then perhaps #3 injector is leaky.
Or the fuel pressure regulator is weak and loosing the pressure, and it takes a few seconds to pressure back up after being turned off.
My wife noticed a gas odor when it started up the other day, I didnt smell it but if she did smell gas, that would point to a flooded cyl at startup I assume.
Once it smooths out, it runs with no issues. it actually runs pretty well since the top end was regasketed and cleaned up.
Opinions on leaky injectors?
I could replace the injectors as a whole set, I think I can pick up a reman set on ebay for under 100 bucks.
The new o2sensors are in, and the computer was cleared.
I started it up it did the same thing, rough idle for about 10 seconds then it smoothed out and idled fine.
It began to pour down rain so I havent driven it yet. Tomorrow it will get a lot of driving.
I was thinking, these injectors are as old as the truck. Could it be that an injector is leaking off the fuel pressure when its turned off, and flooding one cyl? This would explain the nature of the problem, as soon as the gas clears out of the cyl all is well.
If I continue to get a misfire pending code on #3 then perhaps #3 injector is leaky.
Or the fuel pressure regulator is weak and loosing the pressure, and it takes a few seconds to pressure back up after being turned off.
My wife noticed a gas odor when it started up the other day, I didnt smell it but if she did smell gas, that would point to a flooded cyl at startup I assume.
Once it smooths out, it runs with no issues. it actually runs pretty well since the top end was regasketed and cleaned up.
Opinions on leaky injectors?
I could replace the injectors as a whole set, I think I can pick up a reman set on ebay for under 100 bucks.
Moderator
Joined: Jan 2004
Posts: 13,851
Likes: 111
From: SW Va
Good idea to have replaced the O2 sensors, as the P0153 was indicating the bank-2 upstream/before cat converter O2 sensor response was lazy/slow, so it would be behind/slow reporting O2 in the exhaust & make that cyl bank be behind on fuel trim corrections & that can make for driveability woes including a mpg hit, all a vicious circle.
Did you disconnect the battery B- cable while installing the new O2 sensors, so to wipe the old corrupt fuel trim tables the old slow O2 sensors had constructed????
Then performed the cold & warm idle relearn routine here Ford Truck Enthusiasts Forums - View Single Post - high idle problem, that was also likely corrupted by the old O2 sensors. It too is wiped with a battery disconnect, so best we take the time to do it, so the computer can begin to build new fuel trim tables with input from the new O2 sensors & maybe prevent idle & driveability woes by performing the cold & warm idle relearn procedure???
Get a fuel pressure gauge on the fuel rail Schrader valve test port to monitor fuel pressure & pressure leak down, if you suspect #3 injector has a runny nose.
Did you disconnect the battery B- cable while installing the new O2 sensors, so to wipe the old corrupt fuel trim tables the old slow O2 sensors had constructed????
Then performed the cold & warm idle relearn routine here Ford Truck Enthusiasts Forums - View Single Post - high idle problem, that was also likely corrupted by the old O2 sensors. It too is wiped with a battery disconnect, so best we take the time to do it, so the computer can begin to build new fuel trim tables with input from the new O2 sensors & maybe prevent idle & driveability woes by performing the cold & warm idle relearn procedure???
Get a fuel pressure gauge on the fuel rail Schrader valve test port to monitor fuel pressure & pressure leak down, if you suspect #3 injector has a runny nose.
Thread Starter
|
Cross-Country
Joined: Feb 2010
Posts: 67
Likes: 1
Yes I disconnected the battery.
The passengers side o2 sensor was actually backed halfway out and loose. So add a possible before the cat exhaust leak.
Its in tight and sealed now. it did not help the starting thing bit it was getting oddly low MPG on the meter before. Todays running will see what the O2 fix cured.
I'll have to pick up a new Fuel pressure tester... mine seems to have grown legs and walked away.
The passengers side o2 sensor was actually backed halfway out and loose. So add a possible before the cat exhaust leak.
Its in tight and sealed now. it did not help the starting thing bit it was getting oddly low MPG on the meter before. Todays running will see what the O2 fix cured.
I'll have to pick up a new Fuel pressure tester... mine seems to have grown legs and walked away.
Thread
Thread Starter
Forum
Replies
Last Post
Bj Minor
Ford Inline Six, 200, 250, 4.9L / 300
18
Nov 26, 2018 03:16 PM
Jimmy Crab
1987 - 1996 F150 & Larger F-Series Trucks
55
Aug 28, 2016 04:56 AM
el chingadero
Ford Inline Six, 200, 250, 4.9L / 300
4
Oct 26, 2015 02:24 PM