The American Puma - Rough Idle

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Wooticus

New member
Joined
May 27, 2022
Messages
16
Hi all! Posted on here awhile back about getting a Puma over to America, and I did manage to barely get my 97 Ford Puma here, hoping to see what the big brains on here can think of before I start throwing parts into it, some back story...

She ran great, legitimately zero issues. Took her to the car wash to get cleared for agriculture inspection, they pressure wash the engine despite being told just to do the underbody, like many Americans, I'm on a timeline to leave the country, and I don't want to start getting political on here, but let's just skip past the details and say I ate my loss. Part of getting the vehicle to ship is it has to be under a 1/4 tank.

Day of shipping, fire it up to drive 2 miles to the shipper, won't start. Turns out fuel gauge isn't 100% accurate so the car wash probably ran the fuel dry idling it after wash. Put gas in her, fires right up no issues, make halfway through the 2 mile drive, starts bucking like a bronco, dies on the side of the road. Get it towed to the garage next to the shippers, check everything under the sun, finally find out lubing up the throttle valve gets it to run well enough to get to shippers, and we part ways for a couple months while I wait for her to arrive in the states.

Naturally runs absolutely terrible at Texas, but already brought a trailer, load her up and go back home. Since then I've been checking every connector, every wire, and every sensor I can think of trying to find the problem. Here's the issue, what I've done, what I'm suspecting I need to do, but would appreciate any wisdom:

Issue: Fires up fine, idles at normal for about 10 seconds, then idles very rough, sometimes sounds like it's going to stall, then idles very rough some more.

OBD Code: P0102 - Mass or Volume Air Flow A Circuit Low
CReader: Fuel System 1 - CL_Fault

I noticed on the throttle body there is what I can only call a rubber stem that when removed makes the throttle body pull vacuum and idle very rough, but the stem itself is cracked and dry-rotted all over, so not sure if that is a partial-culprit, would appreciate some insight on that one, moving on...

- Checked MAF, replaced it for cheap with an aftermarket part to see if any change as MAF internal wires looked potentially damaged, no change noted.
- Cleaned throttle body.
- Cleaned idle control valve, no damage noted.
- Opened idle inlet temp sensor, no defects noted.
- Checked all vac lines, no leaks heard.
- Checked fuel injectors/fuel lines.
- Checked all lines/wires/hoses for any leaks or disconnects.

I'm going to order a fuel filter in case the gas issue from the UK clogged it, but anytime I throttle, it runs clean, just a very rough idle, so I'm not sure.

I feel like the problem is right in front of me, and I've checked most threads I found related to this, but please let me know your thoughts. Resetting the ECU at time of posting for good measure after everything has been disconnected/re-connected multiple times. Somewhat suspecting an electrical issue due to the first 10 seconds of running being fine, but I'm going to be honest and say I'm a Youtube mechanic here. Pictures with Kansas plates inbound once she's up and running!
 
"I noticed on the throttle body there is what I can only call a rubber stem that when removed makes the throttle body pull vacuum and idle very rough, but the stem itself is cracked and dry-rotted all over, so not sure if that is a partial-culprit, would appreciate some insight on that one, moving on..."
I'm not sure whether you're referring to this blanking plug, but this often fails and causes a rough idle. Can be fixed either by a new one, or a piece of rubber tubing with one end plugged with a screw/glue:
 

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I'm not sure whether you're referring to this blanking plug, but this often fails and causes a rough idle. Can be fixed either by a new one, or a piece of rubber tubing with one end plugged with a screw/glue:
Thank you for the nomenclature. I did try wrapping it in electrical tape for troubleshooting, and idle did clean up a little, will report back when I replace that and fuel filter. Bit of a stretch, but if you know of any stores selling it, that would be awesome! Little harder finding UK/EU stores on a USA search engine now.

Still appreciative of any ideas folks throw out there before I report back. This is my show car/future Sunday driver in Kansas, so (un)fortunately I'm not super rushed for a quick fix, but rather the right fix, and wow do I never have any time on my hands anymore!

EDIT: Found blanking stems. We Yanks apparantely call them vacuum caps hence why I wasn't finding any haha.
 
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