car runs with no fuel pump.
car runs with no fuel pump.
i finished up my kae-t install today and after a long trial and error startup i finally got it to start. the weird thing is, the fuel pump fuse was not in. the pump was not working at all. i took it out first to prime the oil pump and flow some oil thro the block. when i got it started it idles ok but it just kept going with out the fuel pump running. then i put the fuse back in and tried starting the car again and it wouldnt start up. pulled the fuse and it would start. weird stuff here. i know i have a vaccuume leak somewhere i need to fix. but the car should not just keep running without the fuel pump working right? even if there was a vaccuum leak. i am using a brand new walbro 255lph fuel pump and 460cc injectors.
Re: (fiznat)
mine is a 10amp fuse. yes i am pulling the right fuse out because when i put it in i can turn the car to on pos. and hear the fuel pump pressurizing the system. without it the car will still start up. my idle is really ruff and i cant seem to raise it even if i step on the gas. it goes up really slow but cant really rev at all.
do you hear the fuel priming without the fuse in? if so then you have a short somehow, or you hooked the pump up incorrectly or something on that order...
how long does the car run without the fuse in? indefinitely? once the lines are pressurized it will run for a short amount of time without the pump (and i would think even more so with a higher capacity pump but i'm not sure on that... it still may only pressurize the same as the stock pump when it primes).if the car wont go above idle there could be a bunch of problems. the first that comes to mind is that the mafs isn't hooked up right. whenever the mafs plug comes off or isn't sending a good signal the car runs rich at idle and then when you open the throttle it will bog and sputter because it doesn't compensate for the extra air since the air signal isn't there. i have experienced this first hand when i lost the clip for my mafs and the thing kept falling off when i was driving. the first time it happened it scared the hell out of me.
anyhow was the fuel pump a recent upgrade? did the car run fine before? when did this begin and what happened before/ what mods did you do to the car that may have caused this. retrace your steps, because problems like this are almost always related to recent changes in your setup.
how long does the car run without the fuse in? indefinitely? once the lines are pressurized it will run for a short amount of time without the pump (and i would think even more so with a higher capacity pump but i'm not sure on that... it still may only pressurize the same as the stock pump when it primes).if the car wont go above idle there could be a bunch of problems. the first that comes to mind is that the mafs isn't hooked up right. whenever the mafs plug comes off or isn't sending a good signal the car runs rich at idle and then when you open the throttle it will bog and sputter because it doesn't compensate for the extra air since the air signal isn't there. i have experienced this first hand when i lost the clip for my mafs and the thing kept falling off when i was driving. the first time it happened it scared the hell out of me.
anyhow was the fuel pump a recent upgrade? did the car run fine before? when did this begin and what happened before/ what mods did you do to the car that may have caused this. retrace your steps, because problems like this are almost always related to recent changes in your setup.
Re: (hysteria)
the car would just run without stalling at all. i didnt hear the pump kick on when i had the fuse out so i know it was not working. when i put the fuse back in I could hear the pump kick on. the pump is new and i know its working properly. the only wiring for the pump is the positive and the negative so not much to mess up there. i can raise the idle manually @ the TB but at 1000 rpm's the motor is still shaking really badly almost like its about to stall out but its at 1k rpm's. its really weird. i will have to mess with my timing again tomorrow. will the car still startup and run if the timing is off 180*? maybe i just put the dist. in wrong or something. the idle is really ruff even at 1k.
Re: (wild_maxx)
Once pressurized you can run the motor without the pump going, but once pressure dies, no fuel release from the injectors. Read about a fuel system to learn more about it.
Re: (RMiller)
yeah that's what i was talking about, but i mean if it will just run and run and run that doesn't make much sense. when i have to do something with the fuel i actually pull the pump fuse and start the car and let it run till it dies to relieve the fuel pressure in the lines...
Re: (hysteria)
i htink i know what was causeing the mysterious fuel pump issue. turns out that when i was doing my IC piping i forgot to take out the red caps that go in teh endtanks. stupid me. well it will only run now with fuel pump fuse in which is a good thing. now i just have to get it running good
Re: (wild_maxx)
I had a similar situation when I was priming the turbo oil lines with a new engine. I had just installed JWT ecu with 72lbers and Z32 maf, I pulled the fuse for the fuel pump and cranked the engine over till I had oil coming out of the lines. I attacthed the oillines, but forgot to put the fuse back in, the car did start up and was idling quite nicely. WTF? I put the fuse in for the fuel pump and it was running pig rich and wouldn't idle, I couldn't even back it out of the garage. Turns out I had a bad ground for the MAF. After that, all back to normal.
Re: (Frozen240)
yeah i checked my ecu codes and i got a 12 (MAF) and 41(egr i think) how did you regroud your maf out. if the maf is not properly grounded will the ecu not read it at all. and can you start the car with no maf connected?
Re: (wild_maxx)
Yes. The ECU will go into failsafe mode and use a preset rpm based map for fuel. It will also not let you go past 2k rpm.wild_maxx wrote:yeah i checked my ecu codes and i got a 12 (MAF) and 41(egr i think) how did you regroud your maf out. if the maf is not properly grounded will the ecu not read it at all. and can you start the car with no maf connected?