1997 4x4 4.0 2 door LWB.
171,174 codes. no vac leaks.no intake leaks new MAF and TPS, changed PCM. idles fine and takes fuel good trouble is when I accelerate upshifting it stammers and truck bucks like a bad misfire. yet no misfire codes. light throttle runs fine as soon as I give it gas to accelerate it starts to stammer.
thanks in advance

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TJ Settle,
1997 Ford Ranger 4x4 4.0

Classic intake gasket leak.

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1999 Ranger 4.0 and extreme Snap-on tool fetish

Check out the link to the post at the top of this page. If you have an 01+ 4.0 with lean codes (PO171 and/or PO174) look here!

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2000 Ranger Extd Cab XLT, 4X4 Off Road, 4.0L, Auto, 8.8 - 4.10's, 01 grille & lights swap.
69 Mustang, modified 5.0, & 5spd.(project)
99 Explorer Sport, 4.0 SOHC, Auto, 8.8 - 4.10's, PW, PL, PM, Cruise, Tilt. (Wife's DD)
05 F-150 2WD Regular Cab. ( My DD)

Sounds like some of the Same type of Problems I'm having..

Can you Check Intake Idling Vacuum readings and 2500 RPM Vacuum readings?

Can you check Fuel Pressure?..

Cjw

I just had a similar problem with my truck, turned out to be the PCV valve and hose. It was throwing the same codes as well. Cheap part, it is worth a shot.

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1994 Ford Ranger, 4.0L OHV, 4WD, 5SPD

Yes you can check the fuel pressure, I do not know which engine you have in your truck, or what year Ranger you have, but on my 2000 4.0 OHV there is a schraider valve on the fuel rail up on top of the manifold where you could hook a fuel pressure gauge to.

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2000 Ranger Extd Cab XLT, 4X4 Off Road, 4.0L, Auto, 8.8 - 4.10's, 01 grille & lights swap.
69 Mustang, modified 5.0, & 5spd.(project)
99 Explorer Sport, 4.0 SOHC, Auto, 8.8 - 4.10's, PW, PL, PM, Cruise, Tilt. (Wife's DD)
05 F-150 2WD Regular Cab. ( My DD)