I recently bought a 1999 Chevy Suburban 1500 with 87K miles. It is in excellent condition. When I bought it, the only flaw was that the keyless entry and the central locking mechanism did not work. It had a Clifford alarm system installed. After driving from CA to TX without any problems, one morning it started, then quickly died. I tried several times, but it did the same thing. I thought it might be linked to the alarm system, so I had the Clifford stuff removed, but that did not solve the problem. I called a mechanic who thought it sounded like maybe the fuel filter or pump. Because of the earlier electrical problems with the locks, I thought I should check the fuel pump fuses and relays first. When I switched the 20 amp horn fuse (next to the fuel pump fuse), the car started and ran fine. I thought I had fixed a bizarre electical flaw. But the next morning it was back to cranking right up and then quickly dying away. I'm going to try replacing the fuel pump relay, but was wondering if it might be something else? Thanks.

 

Actually it's probably not the relay since the vehicle will run without one. It will take longer to start is all, but once it starts it will run without the relay.

How much fuel is in the tank? If it's the fuel pump or filter, the fuel level can have a bearing. Sometimes a vehicle with a weak fuelpump or stopped up fuelfilter will work better on a full tank and intermittantly on a tank that's really low.

Since the fuel filter is a relatively easy change and probably costs less than $5, and since it could be your culprit, why not do that before you start throwning the more expensive parts at it?