Engine runs rough

2001 FORD RANGER

196,200 MILES • 4 CYL • 2WD • MANUAL

COALMAN

MEMBER
1 POST

Truck listed above has a 2.5 L 4 cylinder with 8 spark plugs, 2 coil packs, etc. The engine seems to run rough. Not missing, no check engine light, just not smooth like it was. Feels a little like a vacuum leak, but I have checked all over for that. Smooths out quite a bit above 2,000 RPMs, but still not quite right.

Feb 21, 2009 at 3:01 AM

SQM

✓Experienced Mechanic
6,383 POSTS

Hello,

Vacuum leak can occur from any of the vacuum hoses. It can also be from leaking intake gasket.
If you have already checked the hoses, it will be a good idea to check if the intake gasket is leaking.
With the engine at idle, spray carburetor cleaner into the base of the manifold. If there is a leak the engine will react to the chemical and will idle higher, then it will go back down after the chemical gets burnt off.

Here is a helpful guide:

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

Also it might be good idea to clean out the throttle body as dirty and debris in the throttle body can create idling or engine running rough issues.

https://www.2carpros.com/articles/throttle-actuator-service

I have attached diagrams for your reference.

Please let me know if you have any questions.
Thank you.

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