Sputtering & Jerking when engine is cold
Thread Starter
|
New User
Joined: Aug 2010
Posts: 13
Likes: 0
Sputtering & Jerking when engine is cold
I have a 2000 Ford Excursion 6.8L V10 with 168,000 miles. I start it when it is cold it sputters and jerks after it warms up it quits doing it. My husband had a mechanic hook it to a computer and nothing showed up. He thinks it's something with the transmission. He has changed all spark plugs and the coil packs look fine. A new fuel filter was put in last year. Also he just put all new screws, nuts, & gaskets on the driver side manifold. It had shifted and was causing fumes to go inside. Does anyone have any suggestions? Thank you for your help.
Cargo Master
Joined: Jul 2009
Posts: 2,885
Likes: 26
From: Chino, California
Check your idle air control valve (IAC valve). What this valve does is it opens when the engine is cold allowing more air to flow into the throttle body...thus allowing it to warm up faster and prevents it from stalling. That is why when you start your engine when it is cold, the RPMs are high. As the engine warms up, it slowly closes shut and your RPMs drop to normal.
When this valve sticks in the closed position, your idle is low and it sputters when cold. As it warms up, it is already in the closed position, thus the normal idle.
This valve is located at the throttle body. Hope this helps.
This problem will not trigger a code or Check Engine Light.
When this valve sticks in the closed position, your idle is low and it sputters when cold. As it warms up, it is already in the closed position, thus the normal idle.
This valve is located at the throttle body. Hope this helps.
This problem will not trigger a code or Check Engine Light.
Thread Starter
|
New User
Joined: Aug 2010
Posts: 13
Likes: 0
Husband took the iac valve out and saw that it was stuck. He cleaned it and fixed it to were it wasn't sticking. The excursion is still sputtering & jerking when cold. We noticed when it does it the rpm's are jumping around.
Cargo Master
Joined: Jul 2009
Posts: 2,885
Likes: 26
From: Chino, California
Does the sputtering and jerking when cold occur when the transmission is in Park or when it is in gear?
I would still suspect it's the IAC valve. It was stuck. Perhaps it's defective?
Were all the rubber boots replaced when the spark plugs were replaced?
I would still suspect it's the IAC valve. It was stuck. Perhaps it's defective?
Were all the rubber boots replaced when the spark plugs were replaced?
More Turbo
Joined: Jul 2010
Posts: 669
Likes: 7
From: Tennessee
I expect it is still the IAC motor. It gets stuck over and over again so unsticking it once is not going to fix the problem. Once it sticks it will probably continue to stick. Does the problem stop when you hold your foot on the gas? Mine did the same thing. It would stick when cold and the engine did not have enough fuel/air to run.
Perry
Perry
Trending Topics
Thread Starter
|
New User
Joined: Aug 2010
Posts: 13
Likes: 0
Yeah when I press on the gas it eventually stops. I will have him buy a new one and hopefully it will quit. I love this vehicle and I want it to last forever. The couple we bought it from never did any maintenance so we have been doing everything to keep it up. When my husband changed the spark plugs it he noticed it still had the original spark plugs in it!!
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
Top 10 Ford Truck Tragedies
Joe Kucinski
Cargo Master
Joined: Jul 2009
Posts: 2,885
Likes: 26
From: Chino, California
You should replace the rubber boots for the spark plugs. They keep water and debris out of the spark plug area. Accumulation of water could cause corrosion and make it difficult to remove the spark plug. A crack in the rubber boot could cause an arc (grounding out) where the spark plug will spark outside, not inside.
I would still replace the IAC. It's not that much. Pep Boys had one for under $50 IIRC.
I would still replace the IAC. It's not that much. Pep Boys had one for under $50 IIRC.
Sit. Stay.
Joined: Oct 2001
Posts: 18,308
Likes: 20
From: Washington State
So when you first start it, it starts and idles fine in Park?
More Turbo
Joined: Jul 2010
Posts: 669
Likes: 7
From: Tennessee
Well the idle servo is going to add throttle as load is applied to the engine. If you put it in drive and the servo is not working it might stall the engine or cause it to run rough. Also the throttle position sensor could be flakey causing the IAC motor to deactivate. I think the V10 uses the throttle position sensor only to detect if the accelerator pedal has been pushed. Have you pulled the codes on the computer? Any autoparts store can do this for you.
Perry
Perry
Posting Guru
Joined: Jun 2005
Posts: 1,268
Likes: 8
From: central Louisiana
ok, this is a wild shot BUT, read over my situation that i had with spark plug boots. i was having a shudder/stalling/jerking issue as well. here's what i went threw chasing it! its long, i know but it might be somewhere to start!
https://www.ford-trucks.com/forums/9...long-post.html
what are the symptoms when you come to a full stop at a red light? some of the "jerking" you could be feeling is the Torque converter trying to fully lock up (like it's in OD at road speeds). if the Torque converter is getting an extra ground signal (ie a spark plug arc, or even a bad alternator diode) it will "think" that it needs to lock up because a ground connection is being completed.
if no codes are present, i'd think you have a ground issue.
https://www.ford-trucks.com/forums/9...long-post.html
what are the symptoms when you come to a full stop at a red light? some of the "jerking" you could be feeling is the Torque converter trying to fully lock up (like it's in OD at road speeds). if the Torque converter is getting an extra ground signal (ie a spark plug arc, or even a bad alternator diode) it will "think" that it needs to lock up because a ground connection is being completed.
if no codes are present, i'd think you have a ground issue.
Posting Guru
Joined: Sep 2008
Posts: 2,498
Likes: 2
TeamMudd has stressed a very good point about the torque trying to lock up.
My Excursion did the same thing only not as bad in a round about way.
I changed the plugs and checked the boots replaceing 2 boots. Sometimes you can look at a boot all day long and not see the problem. The best way I know to check a boot is to squeeze it and if you see any cracks replace it.
This is what I did and the problem was solved. Its been over 2 months and no problem at all.
My Excursion did the same thing only not as bad in a round about way.
I changed the plugs and checked the boots replaceing 2 boots. Sometimes you can look at a boot all day long and not see the problem. The best way I know to check a boot is to squeeze it and if you see any cracks replace it.
This is what I did and the problem was solved. Its been over 2 months and no problem at all.
Thread Starter
|
New User
Joined: Aug 2010
Posts: 13
Likes: 0
We changed the IAC Valve and the sputtering stopped. The jerking isn't coming from the motor. Last night it started to jerk and my husband pushed the O/D button and it quit jerking?? Does this mean anything?