* Potential for Failure: A check valve, if it fails (and they can), could completely block fuel flow, leaving you stranded. This is a far more serious problem than a hard start.
* Incorrect Diagnosis: A hard start after sitting is a common symptom of several issues. A faulty check valve is unlikely to be the *root* cause, it's more likely a symptom of another problem. Adding a check valve without addressing the underlying issue is a band-aid solution that could mask a more serious problem and lead to bigger issues down the line.
* Fuel Pump Issues: The most likely culprit is a failing fuel pump itself, or a leak in the fuel system (causing pressure loss). The check valve would only temporarily address this. A weak fuel pump will eventually fail regardless of the check valve.
* Fuel Pressure Regulator Issues: A faulty fuel pressure regulator could also be responsible for losing pressure overnight.
* Improper Installation: Incorrectly installing a check valve can introduce other problems. You'd need to ensure proper flow direction and compatibility with your fuel system's pressure and flow rate.
What you should do instead:
1. Diagnose the problem: Take your Wrangler to a qualified mechanic or use a fuel pressure gauge to accurately determine the fuel pressure. This will pinpoint the exact issue.
2. Address the root cause: Once you know the cause (weak fuel pump, leaking injector o-rings, faulty pressure regulator, etc.), you can address it properly. Replacing the fuel pump or other failing components is the correct and safe approach.
3. Don't introduce unnecessary components: Adding a check valve without understanding the underlying problem is risky and might create more issues than it solves.
In short, while a check valve *might* temporarily alleviate your hard-starting problem, it's a very poor long-term solution. Focus on correctly diagnosing and fixing the actual cause of the fuel pressure loss.
