larsbars44

I got my sc300 a few months back. The guy i live with bought it for me and replaced the stock fuel pump on the first day. I noticed my fuel pump runs continually and never shuts off. I noticed i had some idling issues, some rough starts, but didn't think much of it. my car stalled at a fast food drive though after idling for like 2 mins it just died. started right back up, but it fluctuates its RPM a lot and sometimes goes down to 500-400.

about a month after the first aftermarket fuel pump was in my car it would not start at a friends house. we were just in it revving it up and having it running, about 20 mins after we played with it and it sat off, i tried to start it. It was not getting fuel, i put the key to the on position, can't hear the fuel pump at all. We banged on the gas tank while trying to start it, nothing. Called AAA to tow me and by the time the truck got there my car started right back up. this happened to me one more time where i was just driving, stop at a place, get back in my car and the fuel pump won't turn on. So he replaced the fuel pump with the same one, just got a new one from warranty.

runs fine for a month or so, a few rough starts and still some bad idling.
For the past 5 days i have been noticing a gargling noise coming from the fuel tank. last night after getting home from work i popped the trunk and as i got out of my car the whole thing died again. it was in park just idling and it gets real low RPM and dies. tried to start it up and its fuel pump was off again! different fuel pump and everything. i waited 20 mins and my car started up rough. Fuel pump runs continuously all the time and gargles now.

Is the wiring bad for the Fuel pump ECU. should i do the 12v mod on a bone stock car? please any support is very appreciated!

I have a video of the sound coming from the fuel pump. can i link a youtube vid?

CatManD3W

iTrader: (18)

Sounds like your fuel pump ECU may be bad.....Did you try the 12V mod to see or check the area behind the trim panel to see if someone else had done it incorrectly?

Could also possibly be worn out capacitors on Engine ECU

Check your EFI relay in fuse box as well

larsbars44

I will get to the ECU in a few hours, Ill let you know how it goes. I doubt the previous owner tried to do this mod. Ill check the relay as well, thanks for the help. Everything is stock on my car besides the cosmetics. Hoping the 12v mod will fix it.

1JZPWRD

iTrader: (59)

It more than likley will. If not, then bad ECU. Rebuild for about 100 or so. I chose to run a seperate relay to trigger the fuel pump on. Takes the guessing out of the equation all together. Decision is up to you.

larsbars44

so rebuilding the Fuel ECU is 100$ but buying a new one is like 1k+ damn...

can i link a youtube video of how my fuel pump sounds? it makes a bubbling or gargling noise a lot.

bigwhite

Have you read the thread on the fuel pump ecu bypass yet? BTW, nice looking SC.