92 jeep cherokee 4.0 2 wheel drive. Was getting hard to start engine dumped oil in air filter box. Got it towed to house. Replaced plugs plug wires. Still wouldn't start. Replaced fuel pump fuel filter finally got fuel no spark. Replaced coil, crank sensor got spark still won't start. Replaced distributor and rotor and cap and wires. Got orange spark got fuel still no start. Replaced computer still no start. Poured gas into intake finally got it to backfire. Any ideas?
Oil blowing into the intake? Do a compression test.
Got good compression
Wiring and ground problems are likely suspects in a 30-year-old vehicle. Check OBD1 codes and see if the computer is detecting any issues.
https://www.fixjeeps.com/jeep-check-engine-codes.html
Where does the pcv route to on that? If it's anywhere aside from the actual manifold, that could be an issue.
I could be wrong but last I was under the hood of one (this isn't recently) could have sworn it dumped to the plastic plumbing vs the engine itself.
Where does the pcv route to on that? If it's anywhere aside from the actual manifold, that could be an issue.
I could be wrong but last I was under the hood of one (this isn't recently) could have sworn it dumped to the plastic plumbing vs the engine itself.
I'm not sure what changes might have been made to the PCV system over the years. I have a '99 and it may not be the same as yours, but here is the description of the PCV system in my shop manual (referred to there as CCV - CrankCase Ventilation) and a diagram showing how it's hooked up.
"On 4.0L 6 cylinder engines, a molded vacuum tube connects manifold vacuum to top of cylinder head (valve) cover at dash panel end. The vacuum fitting contains a fixed orifice of a calibrated size. It meters the amount of crankcase vapors drawn out of the engine."
That air inlet fitting on the front of the valve cover is probably what I was thinking of, is there any sort of additional valve in there or just a fitting & tube?
The front piece is just an air fitting, the rear one has an orifice that serves as a PCV valve.