my fuel pump shuts off after 5 secs

[llama_of_doom]

I have bone stock 91' 240sx that i just finished droping a used KA24DE into. However I am having fuel problems which are preventing it from starting. First of all I have a leak on the hardline in the back of the car, so when the line is pressurized you can clearly see the fuel spraying out from the area (this is how i know when the pump is working) I've been able to crank the engine only a little bit when fuel sprays out and i hear some combustion. But the problem is that the line stops spraying fuel which signals to me that the pump isn't pressurizing the line, and in this case i dont hear any combustion. I will try bypassing the "EGI PUMP" relay but is there anything else that can make the pump work intermitently? When I turn the key to 'ON' am I supposed to hear the pump buzzing continuously, is it going to be very noticable? I would appreciate any tidbits of help.

someone suggested on 240sxforums that its my crank angle sensor but when I searched about checking to see if the crank angle sensor is bad people wrote that a way of looking for a bad crank angle sensor is by checking for spark and I have plenty of spark so can it still be my crank angle sensor? are there other measures I can take to test the crank angle sensor

[llama_of_doom]

no one got any input?

[plane16j]

fuel pressure maybe?has it ever ran with the crack in the fuel line? i would get that fixed....its not @ all safe.

[plane16j]

have you checked fuel pump relay?

[neverlift]

well you could check out the fsm and it will tell yo how to check your cas. but thats too hard these days.sounds like to me that the fueling side of thecas is bad. IIRC the dizzy has 2 sets of slits some are 2* apart and the others are 90* apart,the ones 2* apart are the timing and the 90* apart one are for your fuel pump signal. why I think you have a bad dizzy is the 90* slits once spun tell the ecu to feed the power to the pump. the 5 seconds and off is to prime the injectors for the start up cycle which sprays twice..... all pretty much via fsm you could dcheck for codes too.

[llama_of_doom]

I bought this 240 as a project with a bad motor so I don't know if it ever ran with the fuel leak. But I pulled the 2 hoses just before it goes to the fuel rail and a ton of fuel poured out so I think theres good fuel pressure. When I hear the fuel pump buzzing the line was squirting fuel out all over but when the buzzing stopped the fuel leak stopped too. I bought a new fuel line from a parts car. I realize running a car with a fuel leak is dangerous but I just want to get this damn engine to start already and the end of the line broke off right before I was going to attempt to start it when I was changing the hoses. It always had a bad leak but I thought it was attributed to bad hoses it turned out the hard lines were so rusted the had multiple cranks.

I changed the relay that says erg/pump I am under the impression thats for the fuel pump but correct me if I'm wrong

Ic so I could have sufficient spark because 1 part of the CAS is working but no fuel because the other part of the CAS that controls the signal to the ecu to turn on the fuel pump is bad. Can you tell me what fsm pages are worth looking at for telling how to get the codes and test it. i was looking for it but was unsuccessful in locating it.

aight guys thx for the input I appreciate it

[llama_of_doom]

so can anyone direct me to the pages that may help me test the CAS I was looking and couldnt find it

[llama_of_doom]

no one can help me out locate the page in the repair manual that will give me the info I need to run this test on the CAS?

[slyedog240sx]

the crank angle sensor has no bearing other than to control spark and maybe injector pulse. fix your fuel line b4 you try to diagnose anything further.then check the relay and fuel pressure.

[cubanbob]

Actually I read in the FSM just today that the ECU turns the pump on after it reads 1* from the CAS letting it know the motor is spinning. It's in the EF(Engine Fuel)-EC(Emissions Control Section) page 132ish?