HELP no fuel. not the pump

My 2000 cavalier is having an intermittent starting problem.

Just bought the car. less than 1 week it doesnt start. checked the plugs and wires... all good. sprayed throttle body cleaner into the intake while cranking and it runs. so i know its not getting fuel. take a look at the relay, switch it with that ac relay,(same part) still no start.


check the fuse, its good. put it back in, one last crank before i give up and go to sleep..... It starts and runs fine.

drove to work for two days, no problems. then wont start again, same problem. take it in over the weeked. have a few toyota "mechanics" look at it. they tell me its the fuel pump. I say its electrical.(not getting power to pump).

so at the suggestion of a few "mechanics" i spend $250 dollars on a new fuel pump assembly and filter. after one day of trying to figure out the problem, and 1 day to install the new parts im out 250 dollars and 2 days.


a week and a half latter the car wont start at 4:30 am at the casino. lost some money. car is dead and had to take a cab.

i toyed around a little with my fieldpiece digital multimeter. i put the test leads on the two prongs for the fuel pump that are in the electrical connector near the gas tank. ( i know they are for the pump). had my brother turn the key, it peaks instantly at 10 volts and falls immediately to 1.6 volts.


can anyone shed some light on this problem for me? im no good with electrical. are there any known problems that cause these symptoms?


I think i need to get somebody who is good with electrical to follow the wires all the way and ohm them out to find a break, bad connection, or point of high resistance. my guess is a bad connection somewhere to cause a random problem.

i had similer problem on my 96 cavalier and mine was a fuel relay. i found that it would get hot and cut out for days at a time. its located on the driver side of the firewall right behind the air box. if they didnt change the order between 96 and yours it was the closest to the front of the car. hope i helped.

thanks. the fule pump relay and the ac relay are the same part number. but two seperate relays. ive tried swapping them out with each other when the problem happens, but no results.

i tried to check it on my volt meter. corner to opposed corner (criss cross) for a complete circuit. one side is complete, but the other wont be unless voltage is apllied to first half.

how can i check it out of the car on both sides? i think one side requires a lower voltage then the other. i dont want to go put too much on the wrong side and fry it or anything.

and if it gets hot it should cool off in 1-2 hours shouldnt it?

there is a "fuel switch" its located on the front of the engine compartment. mine is bolted to the same bolt as the horn. barring chevy changing engine compartment design. its a small black piece. it plugs into the bottom. you need to replace the top piece. the piece in my neck of the woods is like 10 bucks. that would be the next best guess i have for you. hope it helps you out.

i bought a new relay and that didnt solve the problem either.

ive never heard of this fuel switch, can you tell me more?

First thing that I would do is double check your fuses to make sure you didn't blow one again, the ignition fuse supplies the battery voltage to your fuel pump relay.
Next, check your fuel filter, (having any drivabilty problems?...engine surges, hesitation on acceleration, cutting out at high speeds) any restriction could be causing your pump to work harder or not pushing enough pressure, speaking of pressure....

Fuel Pressure-Have you checked it? Hook a pressure tester onto the schrader valve and turn the key on. Pressure should be between 41-47 psi and hold there-if it doesn't hold suspect a bad check valve in pump, engine running between 42-50 psi.
Pressure Regulator check-Apply vacuum pressure to P/R with a vacuum pump while watching fuel pressure. Fuel pressure should decrease as vacuum pressure is increased-if not bad P/R.

The voltage drop you got from doing the test by just turning the key in the ON position is normal (the 10v to 1.6v drop) When the ignition key is turned on the PCM energizes the fuel pump relay for about 2 seconds then stops. When the engine is being cranked over the PCM will energize the fuel pump relay as long as it receives reference pulses from the crankshaft position sensor giving you a high voltage.

Bad ground, wire break, have someone that knows what their doing check it.

Question: How is the oil pressure in your car?

Some vehicles (usually the earlier models) are equipped with a fuel pump relay/oil indicator switch, which is used to shut down the fuel pump if you lose oil pressure. The switch is open upon starting and closes when oil pressure reaches around 5-7 psi, if oil presure drops below 2-3 psi the switch will open and simultaneously shut down your fuel pump.
(maybe this is the switch that catfisher is talking about b/c I've never heard of a "fuel switch" either)

Well, hope some or all of this info helps you out...