1999 Grand Cherokee new fuel pump, still won't run

[Jan]

My 1999 Grand Cherokee suddenly wouldn't run and the keychain remote wouldn't work (battery is new). Had the fuel pump and fuel filters replaced. My bill so far is $500+ and it will still won't run. Since the keychain remote won't work, I'm guessing it has something to do with a sensor in the security system. Can someone please tell me which sensor reads the signal from the remote? Or offer any suggestions for my mechanic to try?

Thanks.

 

[SteelHeadz]

I'm guessing that the mechanic has disconnected the battery during the work he was performing. In some cases, the securty system looses it's pin code to restore the function of the remote keyless entry. With the use of a scantool , see if your mechanic can access the RKE module and reprogram the key fob.

 

[Jan]

Thanks for the reply. Yes, the battery was disconnected. The day before I had problems starting it, the key fob quit working. The next time I drove it, it went about a quarter of a mile, shut down and wouldn't start (just cranked). A couple of times it turned over, but then died. Now it still won't run even after replacing the fuel pump. If the pincode needs to be reprogrammed, would that also keep it from starting?

The battery has been replaced in the past and there have been several other times through the years that the battery was disconnected and I've never had a problem after reconnecting it. That's why I think it's a sensor. It seems too coincidental that the key fob quick working at the same time it wouldn't start.

 

[54cj3b]

cps ,fuse,bad ground, plug wires not fully connected ,nss
to reset comp just remove both pos and neg cables from battery and touch them together then reconnect them you may also need to go get your keys reprogrammed

 

[SteelHeadz]

My best advice after checking what 54cj3b suggested is to verify what's there and what's not. Is the security tell tale lamp flashing when the no start occurs?, is fuel present on the fuel rail and within specifications? , is there in fact ignition present on the spark plugs when the key is on the crank position?. Answer these questions and gather up more symptoms that may be relevant to the concern so we can narrow this down.

 

[FloridaCherokee1988]

X2 with Steelheadz, I had the same problem with an 85' Thunderbird with a factory keyless entry and security system, if the mechanic tripped the alarm or it lost it's pin code then the security system could be shutting off the power to your fuel injectors and/or your spark.

 

[Jan]

My best advice after checking what 54cj3b suggested is to verify what's there and what's not. Is the security tell tale lamp flashing when the no start occurs?, is fuel present on the fuel rail and within specifications? , is there in fact ignition present on the spark plugs when the key is on the crank position?. Answer these questions and gather up more symptoms that may be relevant to the concern so we can narrow this down.

I talked to the mechanic and he said it is definitely getting fuel. He hadn't checked the spark plugs because he said they're hard to get to, but he didn't think that was the problem. He did dc and reconnect the battery. I checked the security lamp and it is off and stays off when I try to start it. I talked to the Jeep dealership and their electrical guy says it sounds like one of about four sensors ($400-500 to replace) or possibly the security module ($700-800). He said that on 99's it's rarely a problem with resetting the computer. He also said that diagnostics are more difficult on a 99 because they usually throw more of a generic code that doesn't show a specific part.

The mechanic who has it now could replace the sensor if we could figure out which one is causing the problem.

It's sure not like the old days. We have 1978 Ford Fairmont that my elderly aunt gave us before she died. My husband replaced the fuel pump in it the other day -- $22.99 for the part and about 20 minutes to put it on.

 

[SteelHeadz]

That's a good sign that the securty system might not be the problem. When the mechanic said that there's fuel , did he just check that on the fuel rail or did he verify that it was actually pulsing out of the injectors?. Having fuel pressure in the fuel rail that's within spec. Is great but, if there's a reason for the PCM not to pulse the injectors to spray fuel in the cylinders , that would indicate other symptoms.

 

[FloridaCherokee1988]

Yeah f he didn't check the injectors then that could still be the problem, I had fuel in my fuel rail just not coming out of my injectors.