Question

P0304 2000 Ford Ranger 4.0 V6. Replaced fuel injector, plugs, wires, IAC, MAF. Compression is 150psi (cylinder 5 reading 148 so it seems like it is within tolerance). Engine is idling horribly and mileage is down 10-20% I don't smell a strong fuel smell in exhaust. I have no idea what to check next! Please help!

Answer 1

Hi there,

I think next you should try checking for an intake manifold vacuum leak. You can do this by spraying carb cleaner around the intake manifold with the engine running at idle. If the idle speed increases or smooths out, then you know there is a leak on the intake.