98 Suburban fuel question

[lawjo1978]

So over the weekend I bought a 98 Suburban for a low, low price at a mechanic's auction. Pretty clean body, iebnterior, etc..... This has the Vortec 350 with the spider injector system. The fuel pump was replaced back over a year ago. It's definitely working. But you have to shoot starting fluid in the throttle body and it will start up but doesn't stay for over more than 30 seconds. Or if you hit the gas it will die right out. Is it the spider injector?

 

[SAATR]

The pump being replaced a year ago is irrelevant. You need to put a fuel pressure gauge on it and start tracking the issue down. A bad injector in the spider has a very slim chance of causing a no-start condition. More likely a fuel pressure issue caused by the pump or fuel pressure regulator. Fuel pressure gauges can be had fairly cheap, and are absolutely necessary for diagnosing issues like this on a wide variety of vehicles, so it's a good investment.

Get the gauge, hook it up, turn the key on, and see what kind of pressure you have. If it's less than 55psi, use a pair of needle nosed vice grips with the jaws wrapped (heavily) in electrical tape to pinch off the fuel return line coming from the engine. It should be the smaller of the two fuel pipes coming out of the top of the intake. Follow it down the back of the engine and it will change to a stainless steel braided soft line. Pinch the line off in this area. Check fuel pressure again. You should get over 80psi if the pump is working correctly and the pressure regulator isn't blown out. If it goes high, pull the upper plenum and change the FPR. If it stays low, you have a pump issue. Could be a bad pump, low voltage to the pump, etc.

 

[Ironhead]

Good advice in the first response. Only thing I could add is to check the cheap stuff, such as the fuel filter (super easy to change out), that the fuel lines are not damaged (pinched), and also ensure that the tank does not have sediment, dirt, and other crud in the bottom. On the Suburbans, the tank is under the rear of the truck, so I'm not sure how easy it is to get at the pump. Someone else may chime in on this, perhaps there's an opening in the rear floor of the truck?

 

[df2x4]

On the Suburbans, the tank is under the rear of the truck, so I'm not sure how easy it is to get at the pump. Someone else may chime in on this, perhaps there's an opening in the rear floor of the truck?

Nope, have to drop the tank. Just like the trucks, except you don't have the option to raise the bed instead.