Engine runs rough

2001 FORD RANGER

196,200 MILES • 4 CYL • 2WD • MANUAL

COALMAN

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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 11:01 AM

SQM

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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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Nov 30, 2021 at 1:15 PM