Becky

Hi All,

Really hoping you can help me. I have a 96 Jeep Grand Cherokee, 5.2 that won't start. It died on me a week ago and we had it towed to a local guy we know, thinking it *might* have been the fuel pump. Well, he just replaced it, without really troubleshooting the problem. It didn't work, still wouldn't start. Had it towed home, $248 later. My husband then, after speaking to someone, replaced the crankshaft position sensor. No dice. On a hunch, he checked the fuses and sure enough, the 20 amp fuse was blown. Changed it out, started right up. Went to drive it today and got about 1/4 mile from the house and it died again. Fuse was blown again. Changed it, but it still wouldn't start.

I will tell you that I had a new catalytic converter put on about 2 months ago and need a new O2 sensor put on. I have read that might be an issue? Just trying to figure it out before my husband wants to scrap the whole thing and buy a new car. I love my Jeep and don't want a car payment right now!

Thanks for your help and I will be looking forward to your ideas!

ironmanandy

Try taking the O2 sensor wire off the header (exhaust manifold) where it keeps melting and shorting out that fuse. Might not be the problem but I see that one all the time when folks replace the 02 sensor and let the wires dangle.

Andy-Ironman4x4

ET JEEP

Sorry you are having this problem. First, I do not believe the O2 sensor is the problem. It senses unused oxygen and the PCM uses the info to adjust the fuel-air mixture lean or rich as needed. Now a burnt wire making contact can be a cause for trouble.

The PCM and ASD (auto shut down relay) are the brain and heart of the ignition run operation. When you first turn on the key the PCM-ASD tells the fuel pump to turn on. You should hear it running for a short period. This pressurizes the fuel system for the start. The ASD also sends power to the coil to power the spark plugs. It also sends power to the injectors. So there are a lot of circuits with things going on. The first check would be the ASD and the Fuel Pump Relays. Make sure they are good. Look at your wiring and see if it looks good.

In order for the engine to run you need Air, Fuel and Ignition. Air is a given, rarely a problem. Fuel and ignition are the main problem. For fuel, check that the fuel pump is running. Also, you can attach a fuel pressure gage to check for normal fuel pressure. For ignition, you can remove a plug wire and check for a spark with the engine cranking. Be careful doing this as it can be a shocking experience. Once you have determined if it is a fuel or ignition problem, you can troubleshoot that area.

BTW, which fuse keeps blowing? The fuel pump?