SVT with sudden rough idle, power loss - Ford Focus Forum, Ford Focus ST Forum
Ford Focus Forum
HomeContact UsAbout UsGalleryDiscussion ForumsMarketplace


Go Back   Ford Focus Forum, Ford Focus ST Forum > Ford Focus Tech Discussions > General Technical Chat

General Technical Chat This section is for technical discussions relating to general maintenance, electrical issues, engine trouble, and recalls.

Search This Forum | Image Search | Advanced Search    
Ford Focus Tire & Wheels FocusFanatics Merchandise

 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 01-20-2013, 09:35 PM   #17
6SPD_soul
Focus Addict
 
6SPD_soul's Avatar
 
Join Date: Feb 2008
Fan#: 53637
Location: Soldiers Grove, WI
What I Drive: 2003 Comp Orange EAP SVT

Posts: 1,468
Points 2,489, Level 30
Points: 2,489, Level: 30 Points: 2,489, Level: 30 Points: 2,489, Level: 30
Level Up 26% Completed
Level up: 26% Level up: 26% Level up: 26%
Forum Activity 0%
Activity: 0% Activity: 0% Activity: 0%
FF Reputation: 24 6SPD_soul Great Standing Member
Buy-Sell-Trade Rating: (1)
Well you mostly got good news in that it's not a catastrophic timing failure. I think the fact that you have spark means the CPS is sending plausible info to the PCM and it's responding to that, as far as I know spark (and injector) timing depend primarily on the CPS. And like you said CPS failure should trigger a CEL and no engine starts of any kind. If it were an IAC problem, you should be able to start and keep it running with throttle. And I'm pretty sure the spark tester you bought means the plugs are sparking also, if you have spark at the tester it means that voltage also went through the plug and to ground since it's all inline.

I've had a periodic no start problem in past winters that's a bit like you have, long cranking time and very rough low idle. It's only happened a few times, but once at the suggestion of a friend I disconnected the MAF sensor and it started and ran normally. I looked at the MAF readings later on and it looked totally normally, and it hasn't happened this winter yet. Spark and fuel timing are dictated primarily by the CPS and then inlunced by the MAF sensor which is the primary measure of engine load. I think it's worth a shot given how easy it is. If you refilled the tank right before this happened, I'd also contact the gas station and ask if they've had any problems with gas quality in that time frame. Really unlikely but technically possible. It's worth changing the valve cover gasket but I don't think that's your problem, all 4 cylinders would need to have simultaneously flooded with oil and I don't see that happening.

I just noticed you've got Toms tune, have you sent him a datalog or contacted him yet? He's always telling people to send him datalogs, I have to assume the SCT has the capability of logging useful info. I realize the car isn't running and I'm not familiar with the SCT, but a key on engine off datalog might reveal a sensor spec that's wildly out of line. I kind of think that's what it is, all 4 of your fuel injectors can't have crapped out at once and they're individually controlled, you've got a new fuel pump and filter and good pressure, engine timing must be right based on the compression test. Spark is there and I don't think it would be without reliable CPS info. Or you somehow got fuel so shitty it won't burn.

Best of luck dude, you know you got good news when you did the compression testing.
6SPD_soul is offline  
    Reply With Quote
 

Bookmarks & Social Networks

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Ford Focus Forum, Ford Focus ST Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may 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

Forum Jump


All times are GMT -5. The time now is 07:50 PM.


Copyright 2002-2014 FocusFanatics.com. All Rights Reserved : Privacy Policy : Advertise Information

Focus Fanatics Ford Focus Forum offers many fun ways for you to engage with other Ford Focus Owners from across the world. Whether it be about the aftermarket performance modifications, technical how-to's, European tuned suspension or awesome fuel economy similar to the Cadillac ATS-V, Ford Fusion and Acura TLX. You can find all Ford Focus and Focus ST related information here. Join our Ford Focus discussion forums and chat with local Focus enthusiasts in your area.