No Start - Fuel Pump related

Post by **Sockington** » Thu May 19, 2005 3:12 pm

I picked up a 1990 240sx with a no-start.

The motor cranks fine - there is no issue there. When the key is turned to the start position, but not cranked over, the fuel pump cannot be heard priming. The previous owner put in a used sending unit when trying to diagnose the problem, but he was unsucessful. I assume it's a relay somewhere down the line not sending voltage to the pump.

Any ideas? Is there a fuel pump relay? Where abouts is it? I checked the fuse and it seemed fine, so there's one small thing eliminated.

I'd like to see how this thing runs before I decide whether I want to 2.3Turbo the car. I might just source out the 5speed parts and go from there.

Thanks,Chris

Post by **slc240sxse** » Thu May 19, 2005 5:06 pm

Had the same problem on my 96. On the 96, I replaced the fuel pump, and replaced the relay.. but the relay was for other problems. There is a relay on the 96' its located down in the fuse box. On your 90 I'll bet there's one too, but where it is, I have no idea. I would be willing to bet that it's your fuel pump. Get a FSM, and have a look!

One way to check that you're not getting any fuel is to remove the line either before or after the fuel filter that is in the engine compartment. Put the line into a jar or something, and turn on the key. It should prime the rail. If you get nothing, then it's your pump / relay.

The chances of it being your relay are quite slim however, but once you get access to the fuel pump, check the impedence on it to make sure that it is within range.

Post by **Sockington** » Thu May 19, 2005 7:40 pm

slc240sxse wrote:Fuel pump related answer

Is there a Walbro 255LPH/High Pressure available for our cars? I might as well replace it right whilst I'm at it.

EDIT: Found one on eBay. $100USD plus shipping - looks like I might be in luck after all.
Modified by Sockington at 11:03 PM 5/19/2005

Post by **slc240sxse** » Fri May 20, 2005 6:08 am

Sockington wrote:
Is there a Walbro 255LPH/High Pressure available for our cars? I might as well replace it right whilst I'm at it.

Yes. I would go for it, they're about the same price if my memory doesnt slip (due to too much alcohol id say)

Post by **mss5413** » Fri May 20, 2005 4:31 pm

By pass the circuit first to make to isolate whether you have a fuel pump problem or a problem in the circuit. Use a jumper wire to go directly from the battery to the fuel pump connector and use the car chassis as a ground for your ground connection. Of course if the fuel pump turns on, then you have a circuit problem and vise versa. There should be a relay box near the battery for the fuel pump relay if your going to check relays.

Post by **Sockington** » Sat May 21, 2005 8:14 pm

mss5413 wrote:By pass the circuit first to make to isolate whether you have a fuel pump problem or a problem in the circuit. Use a jumper wire to go directly from the battery to the fuel pump connector and use the car chassis as a ground for your ground connection. Of course if the fuel pump turns on, then you have a circuit problem and vise versa. There should be a relay box near the battery for the fuel pump relay if your going to check relays.

Sounds like a great idea... except I'd need to know a little more. For instance, which wire is which? etc. (I don't have a Haynes or Chilton's yet)