Thursday, June 2, 2011

How to tell fuel pump is broken - 1994 Chevy Suburban?

1994 Chevrolet Suburban 195,000 miles. 2 days ago had new cap, rotor, control module, wires and plugs put in by my mechanic. Before this work the vehicle would only start intermittanly (thought control module was bad). It never stoped running after it started but after starting it up a couple of times it just stopped starting. It turns over fine. Mechanic said he checked fuel pump - with in specs. Usually starts after sitting but since tune up it did the same thing wouldnt start after a couple of times and now wont start. Today, pulled air cleaner off to look at injectors but no fuel coming out when vehicle is turning over. Gave tank a few whacks with hammer to see if I could jar fuel pump but nothing. Is probably fuel pump but could it be - coil? IAC Valve? fuel pump relay (how to check)? oil pump? pick up coil (what is this)? Any advice to taking out fuel tank to change fuel pump? Dont want to pay $500 of labor just to take out tank to replace $75 part. Thanks for any helpHow to tell fuel pump is broken - 1994 Chevy Suburban?
Like every one else said check to see if the pump works and the filter is not clogged. Turn on the key without cranking the engine. For about 1/2 second the fuel pump will run to pressurize the fuel system and you will here the quiet buzzing noise it makes in the area of the fuel tank. If you can hear the pump running pull the coil wire and crank the engine, if you dont get any spark then the problem is the ignition module. The module sends signal to the injectors and the coil because they have to fire in time with each other!So when one isnt working the other one usually doesnt either!How to tell fuel pump is broken - 1994 Chevy Suburban?
Bad fuel pressure regulator may be bleeding off pressure to the return line or crank/cam sensor is bad and computer won't fire the injectors because of no signal. Do you hear the fuel pump hum when you turn the key on? If not, could be a bad pump or relay...test for power coming from the relay to the pump....check for a bad ground as well. If the pump hums and you have good pressure, I'd say you have other issues like the sensors. Best to buy a shop manual like Chilton or Haynes for the procedure on pulling the tank if needed.How to tell fuel pump is broken - 1994 Chevy Suburban?
If you can find it, check the fuel filter. It might be clogged with dirt, which would certainly starve your engine of fuel. That would be a relatively cheap and easy fix.How to tell fuel pump is broken - 1994 Chevy Suburban?
You didn't mention checking fuel filter?

disconnect fuel line between tank /engine

turn eng over see if getting gas flow?How to tell fuel pump is broken - 1994 Chevy Suburban?
before removing the tank, check for a clogged fuel line. Als, cneck to be sure that there is power going to the fuel pump.