• Sign Up! To view all forums and unlock additional cool features

    Welcome to the #1 Fiesta ST Forum and Fiesta ST community dedicated to Fiesta ST owners and enthusiasts. Register for an account, it's free and it's easy, so don't hesitate to join the Fiesta ST Forum today!


And she just died for the 1st time

LilPartyBox

1000 Post Club
Premium Account
Messages
1,493
Likes
777
Location
NYC
#1
I'm sitting in traffic waiting on a red light and she just shuts off. I've had her since new and closing in on 100k miles & this has NEVER happened before. So she starts right up and I start logging. It took a bit but a few traffic lights later she stumbles bad but doesn't shut off. You guys know that EVAP stumble...but I filled up days ago & I'm sitting at half a tank so WTF? It happens a few more times but she's driving totally normal otherwise.

I pulled the logs. Here's her story...

When happy, vacuum is about -10, RPMs are 750 or so & timing in cyl 3 (the only one i log) fluctuates b/n -1.7 to 1.8.

Then vacuum starts to wobble b/n -9 & -10. During this initial wobble timing start to advance to a high of almost 22. But the idle holds above 700.

As the RPMs begin to fall, timing falls as well but stays relatively high, from 22 to 11. Vacuum drops as low as 8.2. The RPMs fall as low ~ 500 during the 2 seconds or so that she stumbles.

I don't want to just throw money at randoms parts. So, fellow FiSTocracy and all of its accumulated wisdom...

Do I:

1) buy plugs? My NGK Iridium (LTR7IX-11) only have 10k on them and I've run them without issues for double that.

2) buy ignition coils? They do have 100k on them

3) do the whole EVAP canister thing even tho that makes no sense to me considering I hadn't just filled up.

4) have a vacuum and/or boost leak that is somehow intermittent?

Thx for helping me rescue her!

1745452731518.png
 


Messages
143
Likes
129
Location
Mesa, Arizona, USA
#3
I just had my low side fuel pressure sensor go out on me on Monday... pull up the monitors for lowside FP actual & expected. the numbers can be temperature dependent. you don't want to see 50-65 avg at idle (as far as i know). i 2nd what TyphoonFiST asks. my car threw P008B and P0087, and i'd be driving it and the car would seemingly throw itself into limp mode, and it felt like the accelerator pedal didn't do squat, i couldn't bring rpms up, and boost barely went to 1psi. it did this four or five times and acted like it was on a switch.

I couldn't see AFR in your log sheet so it'd be nice to get the raw file.
 




Top