Overview
The Crown Automotive J3240172 is a natural finish mechanical fuel pump for the 1987–1990 Jeep Wrangler (YJ) with the 4.2L 258 engine. It has a front inlet fitting and is a direct fit with stock flow and pressure ratings.
A mechanical pump is driven by the engine rather than by an electric motor, so it is a different design from an in-tank electric pump.
Key features
- Mechanical design driven by the engine
- Front inlet fitting
- Natural finish
- Fits the 4.2L 258 engine
Mechanical pump basics
A mechanical fuel pump is driven by a lever and pushrod or eccentric on the engine, so its output rises and falls with engine speed. That design means the pump works without an electric motor, but the lever and the camshaft contact surface wear over time. A pump that is weak, noisy, or slow to fill the carburetor at startup is worth checking before replacing other fuel system parts.
When replacing a mechanical pump, inspect the pushrod and the cam lobe it rides on, since a worn pushrod can limit output even with a new pump. Clean the mounting surface, use a fresh gasket, and tighten the mounting fasteners evenly. Check the inlet hose for cracks and the fittings for seepage after the engine has run for a while.
- Inspect the pushrod and cam lobe for wear
- Clean the mounting surface before installing
- Use a new gasket at the mounting flange
- Check fittings for seepage after the engine runs
Specifications
| Brand | Crown Automotive |
|---|---|
| Part number | J3240172 |
| UPC | 848399061154 |
| Pump type | Mechanical |
| Finish | Natural |
| Inlet | Front inlet fitting |
| Engine application | 4.2L 258 |
| Flow rating | Stock |
| Pressure rating | Stock |
| Fitment designation | Direct fit |
Vehicle fitment
It fits the 1987–1990 Jeep Wrangler (YJ) in Base, Islander, Laredo, S, Sahara and Sport trims.
Other YJ years and TJ or later Wranglers are not on this list. Confirm your vehicle’s year, model and trim before ordering.
Installation notes
Fuel system work should be done with the engine off, and the new pump and fittings should be checked for leaks after installation.
What’s included
The item is the mechanical fuel pump with its front inlet fitting. Check gaskets and mounting hardware against your installation before starting.
