I have a 1990 Ranger 4.0. It has been bucking lately at highway speeds. The transmission shop said it is an engine problem and it does this when the torque converter is in lock up. They said it was the Camshaft Synchronizer. I have been unable to find one for this year and engine type. Does it even have one? Is it called something else? Any Ideas?

Thanks

 

Welcome to the forum

No, unless it was a Calif. sold 1990 Ranger
1990-1994 Rangers didn't use cam sensors, 1995 and up did
Calif. required it for stricter emissions, also required EGR system

Bucking in a 4.0l is almost always a dirty MAF sensor, not bad, just dirty, easy to clean these

Other reasons are
"Bad gas", too much water in the gas, usually noticed the day AFTER getting the bad gas
old spark plugs or spark plug wires
cracked Coil Pack

 

Thanks. I'll look into those. Thw MAF sensor is not very old. I'll look into the ignition system, coil, plugs, wires etc then move into fuel.

 

MAF sensor should be cleaned once a year on the 4.0ls
Fuel filter replaced every 5 years on any vehicle

O2 sensors last 12years then they run out of the chemical used to detect Oxygen, these are the ONLY sensors that wear out, has a time limit
100k miles is the limit for miles used, 12 years is the drop dead time limit

Can of Seafoam, or similar, injector cleaner once a year in the gas tank also helps the older 4.0ls