Bad fuel pump?

[nochance]

I've got a 1996 Jeep Grand Cherokee Laredo. It needed a jumpstart last night, and had to call AAA. It worked. This morning I went to go out, only to find the battery was dead. Called AAA again. He came out, jumped it, but it wouldn't stay on. They towed it to Sears, and they said the battery was pretty much dead.

So I had them install an Optima Redtop. He comes back out and tells me the battery it self is fine, but the car is acting funny. It's acting like it needs a jump again, but if you give it gas, it starts right up.

Anyone know what part(s) this sympton would relate to? Also I should say that I installed an after market radio and some component speakers and a small amp. They worked fine, but I had a blown fuse. So it was trial and error pulling them out and checking (this was on the inside panel, passenger side). I did it one by one to make sure there was no mistake on my part. Would removing any of the fuses for any reason effect my problem? I don't know much about this...

[BenBB]

when the car is on if you turn the key all the way but dont start it, you can usually hear the fuel pump kick in ( a little hum sound), but if you dont then it's probably messed up. Other than that i dont really know how to check for other symptoms.

[wpatters1229]

I just went through all of that with a 93. Crawl under the gas tank and have someone turn on the key without starting and you should easily hear the fuel pump. If you don't then there is a connector that you can see by the fuel filter that you can pull apart and check for 12 volts. Both grd and 12v + are in the connector. If you have 12v and you did not hear the fuel pump....bad pump ($899) in my case, parts and labor. Could also just be the fuel filter. There is also a PCM and pulling all those fuses and plugging them back in might have damaged the PCM...computer. There is also a fuel pump relay that controls that along with a valve on the fuel injection rail. Almost need a computer to figure it out. Like I said mine was easy since I had 12volts but no sound coming out of the pump and it would start sometimes but not stay running. Then it finally stayed dead.

[J&J56]

Hey. The not running after it starts is probably the fuel pump make sure that it's primming the system and also staying on after it starts. The easiest way to check this is to put a fuel pressure guage on the fuel rail above the injectors(about $30.00). The dead batery in the morning is most likely caused by the electrical system. Does it not start after sitting for a while or does it do it right after you turn it off and try to restart it? If it only does it after it has been sitting a while then it's probably caused by a draw on the electrical system. (probably has something to do with how you wired the stereo).

[1swift1]

I just replaced my fuel pump after some lenghty diagnositics. It was a bit difficult to pinpoint because the pump worked sporadically. Check my earlier thread entitled "Faulty PCM" for more info. I did not have any battery problems though.