Miss at idle when wet - Ford F150 Forum - Community of Ford Truck Fans

Go Back   Ford F150 Forum - Community of Ford Truck Fans > Late Model F150s > 2004 - 2008 Ford F150
Log In 


Miss at idle when wet

Reply
 
 
 
 
Thread Tools Search this Thread
Old 08-07-2014, 11:13 PM   #1
Senior Member
 
Join Date: Mar 2014
Posts: 152
Thanked 11 Times in 9 Posts
Feedback Score: 0 reviews
Unhappy Miss at idle when wet

Guys I've got a significant miss (stumble) at idle after I go through a really large puddle or even an automated car wash. Once I let the truck sit for a few hours and dry, the miss goes away. It seems like moisture is causing the problem. I'm thinking about letting it dry out and taking a spray bottle and run the truck and start spraying till it stumbles.

It has to be a coil or plug or electrical in nature I think. A vacuum leak would not be intermittent like this I would think.

Thoughts?
__________________
2004 SCAB 6.5 RWD 304k Tow Beast
New 5.4 engine, 3 Speed Electric Fan Conversion w/ Painless F5, ScanGauge II, RAS, Monroe Load Assist shocks & AirRide 5k bags, Gibson Exhaust system, Equal-i-zer 10k 4 point sway/weight dist., Curt progressive brake controller, Powerstroke 6.0 31 row transmission cooler & external filter
sigmanf150 is offline   Reply With Quote
Join F150 Forum

Join F150Forum.com Today - It's Totally Free!

Are you a Ford F150 fan? If so we invite you to join our community and see what it has to offer. Our site is specifically designed for you and it's a great place for Ford F150 Fans to meet online.
Once you join you'll be able to post messages, upload pictures of your truck, and have a great time with other Ford F150 fans. Whether your an old timer or just bought your F150 you'll find that F150Forum.com is a great community to join. Best of all it's totally free!

Join F150Forum.com Today! - Click Here JOIN FOR FREE


-->
Old 08-08-2014, 12:44 AM   #2
Bleeding Ford Blue
 
Summers22's Avatar
 
Join Date: Feb 2014
Location: Kansas
Posts: 3,123
Thanked 288 Times in 244 Posts
Feedback Score: 1 reviews
Default

Well COP's would do that, but not to the extent of a puddle. Most likely your FPDM on your rear axle. They get corroded and short out.
Summers22 is offline   Reply With Quote
Old 08-08-2014, 01:23 AM   #3
Senior Member
 
Join Date: Mar 2014
Posts: 152
Thanked 11 Times in 9 Posts
Feedback Score: 0 reviews
Default

Quote:
Originally Posted by Summers22 View Post
Well COP's would do that, but not to the extent of a puddle. Most likely your FPDM on your rear axle. They get corroded and short out.
Hmm. Hadn't thought about the FPDM. Truck does have 293k. Is there a way to test it?
__________________
2004 SCAB 6.5 RWD 304k Tow Beast
New 5.4 engine, 3 Speed Electric Fan Conversion w/ Painless F5, ScanGauge II, RAS, Monroe Load Assist shocks & AirRide 5k bags, Gibson Exhaust system, Equal-i-zer 10k 4 point sway/weight dist., Curt progressive brake controller, Powerstroke 6.0 31 row transmission cooler & external filter
sigmanf150 is offline   Reply With Quote
Old 08-08-2014, 01:31 AM   #4
Bleeding Ford Blue
 
Summers22's Avatar
 
Join Date: Feb 2014
Location: Kansas
Posts: 3,123
Thanked 288 Times in 244 Posts
Feedback Score: 1 reviews
Default

Yeah, drop your spare and pull it. It has a aluminum housing and when resting against the axle that is steel, it corrodes. It will look real nasty or okay. A visual inspection after removing it will tell all.
Summers22 is offline   Reply With Quote
Old 08-15-2014, 01:21 AM   #5
Senior Member
 
Join Date: Mar 2014
Posts: 152
Thanked 11 Times in 9 Posts
Feedback Score: 0 reviews
Default

Well, I changed the FPDM with a new Doorman unit with the stand offs, but I still had the problem of rough idle and misses after a car wash, so I used a spray bottle and sprayed the first COP on the passenger side and sure enough, it started rumbling and missing. So I blew out the cavity with compressed air, removed the coil pack and the spark plug, changed it with a new Motorcraft SP-515 plug, new boot and spring, greased it up, tested the COP for primary and secondary resistance, and put everything back together. Fired right up and no more missing!
__________________
2004 SCAB 6.5 RWD 304k Tow Beast
New 5.4 engine, 3 Speed Electric Fan Conversion w/ Painless F5, ScanGauge II, RAS, Monroe Load Assist shocks & AirRide 5k bags, Gibson Exhaust system, Equal-i-zer 10k 4 point sway/weight dist., Curt progressive brake controller, Powerstroke 6.0 31 row transmission cooler & external filter
sigmanf150 is offline   Reply With Quote
 
 
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


All times are GMT -4. The time now is 01:21 PM.


Copyright 2006 - 20011 F150forum.com
This site is in no way affiliated with the Ford Motor Company.