Rough idling.

ALVAREZ84

MEMBER
1997 FORD ESCORT
4 CYL
FWD
MANUAL
176,000 MILES

I'm working on my friends 97 escort because it idles rough and wants to stall and some times it does, but it will always start right back up. When accelerating the car is fine smooth shift smooth acceleration. Just when its stops it idles rough . I changed the plugs and wires but it still does it. Could it be a fuel related problem like a filter clogged or something? Thanks for any help you can offer.

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

Can almost guarantee on this vehicle that this is a vacuum leak. I have seen enough of these to know that the intake leaks and causes this issue to a T.

Here is a guide that will help with finding the leak:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

https://youtu.be/4ktw1X4W_-k

If there is no leak then the fuel pressure would be the next thing to check. If the pressure is weak then it will cause an unstable idle but restart each time as the pressure is likely just good enough to get it to fire then run poorly or stall.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Lastly we need to monitor the o2 sensor data. If this all checks out then we need to find out if it is running rich or lean. However, if it is lean, I suspect you have an air flow sensor issue or missed the vacuum leak.

Below is a chart that will help with reading the o2 sensor data to find out if it is rich or lean.

Please let us know what questions you have and we can go from there.

Thanks

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