am i messing up as i check for voltage at fuel pump connector? - Toyota Nation Forum : Toyota Car and Truck Forums

msingell · 01-23-2012, 03:14 PM

hi everybody. im trying to help my gf out and get her 1999 camry le v6 running again. the car has had a history of rough or no starts in extreme weather which i am hoping is an idle air control valve problem. but now, i dont detect any voltage at the fuel pump connector.

i went out to the library, got the haynes manual and began to check the fueling system. there is no whir or sound of anytype from the fuel pump when the key is turned to on. all fuses and relays checkout and im now at the last step of electrical diagnosis and im either checking the fuel pump connector wrong, or there truly is no voltage at this connector.

i found a post on this site stating that the bottom 2 wires of the fuel pump electrical harness were the power to the fuel pump so i checked for voltage at each and neither has a voltage reading with or without the engine turned to on. do i need to actually crank the engine? i wouldnt think so, but maybe im missing something. any ideas or advice are greatly appreciated. thanks everyone!

***fenixus*** · 01-23-2012, 03:35 PM

since all fuses and relays check out, I'd check the Neutral Safety Switch (NSS). it will not send any power to starter and fuel pump if that happens.

Stillrunning · 01-23-2012, 04:02 PM

Quote:

Originally Posted by msingell

i found a post on this site stating that the bottom 2 wires of the fuel pump electrical harness were the power to the fuel pump so i checked for voltage at each and neither has a voltage reading with or without the engine turned to on.

To have a voltage (potential difference) reading you will need to attach your red lead the live feed + and the black lead to ground. When you say the engine is turned on, do mean running, or just key to on position.

msingell · 01-23-2012, 04:09 PM

i cant get voltage when the key is out OR when i turn the key to the on position. i have not tried to measure voltage as i crank the engine. thanks for the replies everyone. the nss is something i never have came across in the manual. i tried to start the car in neutral and got the same result. i know a complete cleaning is the only way to remedy a bad nss, i was just hoping for a miracle that the car would start in neutral ( its an automatic ).

thus far, ive been sticking my probes into the bottom 2 leads and neither has voltage ( i dont know which is the ground and which is live )

msingell · 01-23-2012, 04:21 PM

i just went out and over the last few start attempts, something has changed.

so im going to go back to the start.

the car would be hard to start sometimes in extreme weather. mt gf drove it over to my place and it wouldnt start. its been there ever since. for the first few days, the engine would crank and it almost sounded like the car wanted to start, it would get a little fuel, rpms would go up for maybe a second then the car would die. i could never keep the car at idle. i checked fuses, relays and when i didnt hear the fuel pump prime, thats when i honed in on the fueling. i checked everything up to the pump harness. i know im making good enough contact on those leads and neither of the bottom 2 have voltage. ( i would put + in one and ground in the other, then flip flop the 2 and never got a voltage reading.

now

the initial firing is totally gone and all i have is machine gun clicking that sounds like a relay on auto fire. maybe the next time i go out there the thing will just be gone. i doubt it tho.

Stillrunning · 01-23-2012, 04:32 PM

Quote:

Originally Posted by msingell

( i dont know which is the ground and which is live )

Ground does not have to be a wire, you're better off touching the black lead to body and not to the other wire connection. By doing that you'll find which wire is power. Try doing it when you're attempting to start the car - key to start.

Quote:

the initial firing is totally gone and all i have is machine gun clicking that sounds like a relay on auto fire.

Sounds like your battery is low, starter is gone, or you have a bad starter/battery connection. The clicking could be the starter relay.

msingell · 01-23-2012, 05:04 PM

srsly, thanks to all who gave their advice. i tried to jump the car, but the voltage reads fine and it still doesnt start. i checked the starter relay and it has continuity at 2 of the terminals and no continuity at the other 2 terminals of the starter relay. im still getting this machine gun like clicking noise. i hate my life!