Won't start, fuel pump?

[Hasdrubal]

Car died on the freeway at normal speed, just lost drive without warning. Seems like it's a fuel problem, because it cranked over just fine, battery was replaced only a few weeks ago. Had the car towed home and replaced the main relay, no change. I'm not hearing the fuel pump run when I first turn the key, and it's a Walbro, which was loud enough to notice.

I don't think it's the ignition switch because it doesn't try to fire at all, and from reading others' problems it seems like those cause the car to fire and then die when the key is released.

I'm not too good with the service manual, but I already tried jumping the fuel pump resistor. No blown fuses in the kick panel (are there other fuses involved in the fuel system?), tried unplugging the O2 sensors (from another thread) and still nothing.

I'd like to check the fuel pump, one post suggested putting 12v to the pump wires, but I'm not sure where the plug is. Can anyone point me in the right direction for this? If it makes any difference, I'm also running an AEM standalone.

I don't mind taking the car to a shop under normal circumstances, but I don't like the idea of towing it 60 miles. Would rather spend the money on parts.

 

[pgilliam1]

To see if your pump is making pressure you can pull the fuel line off at the fuel rail and stick it in a gallon milk jug (or similiar container). Then have someone turn the key on and see if fuel comes out (it comes out fast so be ready to turn the key off). If no pressure, you can apply 12V directly to the pump connector (between the seats to the right of the Main Relay when facing the firewall) and see if the pump works that way. Good Luck!

 

[redacuransx921]

yet again another prime member posted about this check your main relay thats prob what it is

 

[Oyagi]

He said in his post that he's already replaced the main relay.

My car did the same thing, I'm also running a Walbro and aem ems, so you are scaring me! New main relay is enroute and I'm hoping it will solve my problem (fingers crossed).


Posted from my iPhone

 

[usafdarkhorse]

yet again another prime member posted about this check your main relay thats prob what it is

He said in the third sentence that he replaced it unless the new unit was bad.

I agree on trying to get 12V to the pump to see if it runs. Anything that's aftermarket usually has less longevity than an OEM unit and Walbros sometimes crap out pretty early, even sooner if it's a knockoff Walbro.

If your car ran fine before with the standalone, you haven't touched anything, and it's now doing this, I wouldn't suspect the engine management.

Hope some of this helps.

 

[shawn110975]

thats why I always replace with OEM no matter the price.

whats 30 bucks when you have to have your car towed for 180.

hope you get her back up and running

 

[davidf]

Did you replace the "fuel pump" relay as well? Several relays under the front will interchange with each other, unfortunately not so with the FP relay in the rear.

 

[Hasdrubal]

Thanks everyone, and I know what you mean about OEM being higher quality than aftermarket, I got the Walbro thinking I needed extra flow for a BBSC, but the car is only making 355hp and I bet the stock pump would be just fine. Not planning to go higher power levels than that, anyways.

Pgilliam1, do you mean the wires that go to the fuel pump relay (I think that's what the small black box is, about 1" cube)?

I'm at work now and won't be able to check the pump until morning, but looking forward to figuring this thing out.

 

[pgilliam1]

Pgilliam1, do you mean the wires that go to the fuel pump relay (I think that's what the small black box is, about 1" cube.

No, you should be able to access the wire connector that goes directly to the fuel pump through the firewall and apply 12V there. It's been a while since I resoldered my main relay and I don't remember if you have to remove a plate from the firewall to get to the connector or not???

 

[DDozier]

No, you should be able to access the wire connector that goes directly to the fuel pump through the firewall and apply 12V there. It's been a while since I resoldered my main relay and I don't remember if you have to remove a plate from the firewall to get to the connector or not???

Fuel pump connections are at the service panel located behind the bulkhead cover directly behind the Drivers seat, it is round light gauge aluminum and held in place by three screws. There is a connector for fuel pump power and for the fuel sending unit. Looking at the connector the two heavier wires run the pump. Use a multimeter and check for voltage at the connector when the key is turned "on". No voltage bad relay or fuse, voltage means bad pump or connection at pump. Make sure you probe the heavier gauge wires as there will be voltage at the sending unit with the key in the "on" position.

Dave

 

[comtec]

1991 service manual
11-106 Starts the flow chart.
11-107 shows the connector and the 12v lead.

1995-2005
11-142 shows more detail, although the wire is Black/Red instead of BLK/YED :wink:


Remember if you try putting 12V to the pump that the details are for the terminal side. Looking at the wire side would be reversed.


Mike

 

[Hasdrubal]

Just ran 12v to the fuel pump, which seems to run fine. I've got a fuel pump relay already in the mail, is there any other part that I should look at in the mean time? Mainly just glad I don't have to drop the tank.

Thanks again to everyone.

 

[pgilliam1]

As mentioned above, there's always a chance the new main relay is defective (if you tap it while the ignition is on sometimes that will jostle the bad solder connections enough to kick it on - if that's the problem). Hopefully the new relay will solve it for you. Be sure to let us know the solution.

 

[Hasdrubal]

Just put the new fuel pump relay in, pump still doesn't come on. When I turn the key, I hear a click from the main relay and two clicks from the fuel pump relay.

Are there any other fuses besides the one in the kick panel? I cant' see the engine bay fuse box very well, it looks like it was moved when the BBSC was installed.

 

[pgilliam1]

If the fuse box was moved, there is a chance the wires were stretched. Check the relay connections (with the relay removed) into the fuse box and make sure you have 12v there with the ignition on. Go forward from there towards the main relay connections looking for 12v. Interesting or frustrating - depending on how you look at it :wink:.

 

[comtec]

Did you ever check voltage at the fuel pump connector?


Things to check.

Grounds
G101 and G102
G403 and G405

fuse #2 and #5 dash fuse box

Fuel pump resistor= checked

Fuel pump relay= replaced

Main relay- replaced

ECU- provides ground for fuel pump control and fuel cutoff control.



Mike

 

[nsxotic911]

FYI, if you get AAA+, they will tow you upto 100 miles for upto 4 tows (or service calls). I usually use at least 4 / yr amongs friends and family... AAA iphone app makes it easy.

Back to your issue - your car sounds similar to mine. I'm assuming you don't have OBD that you can plug in and get codes? That would be the first thing to do.

With the Walboro - my fuel map is sensitive to temperature. If it's too cold, it won't turn on... where was the car tuned and how well does it generally drive in the stupid cold, rain and ugliness we are experiencing recently (alwasys) in the PNW.

 

[S2G-Unit]

Any more of you guys have the same problem & figure out what to replace?

 

[dablackgoku1234]

I've had this happen to me on the track. Car just died out of nowhere. It cranked, but wouldn't fire up.

Replaced main relay, shorted fuel pump resistor, still nothing. For me, it was the fuel pump itself. I went with an OEM Denso unit from RockAuto.

 

[Valhalla]

I just lived this nightmare and replaced all the usual suspects. Main relay, ignition switch, etc. Car wouldn't stay lit. Had to have it towed 30+ miles.

Found out that when the Walbro (allegedly) was installed, it was installed too far down in the tank and the pickup screen was against the bottom of the tank and bent back upwards. This caused the pump to push harder as the flow was restricted. But that was not the bad part. The wiring inside the tank had heat wrap on the wires that eventually fell apart (within one year) exposing both wires. And the heat generated by the strain caused the wires to overheat and fuse together.

Why did I use the word "alleged"? I bought the pump from a reputable after market supplier and the box that the pump arrived, it read Walbro on the box. But that is not what it was. So be very careful when ordering.

Now that I have a real Walbro the pressure in my fuel rail at idle is 58#. I had to have my engine management system remapped to handle this new and improved fuel delivery.

 

[brettowen]

There should be a rule that if you post requesting help with a problem, you have to close the thread with the final fix. I would guess it was the fuel pump that fixed the OP's issue but would like to know for sure.

 

[Nero Tenebre]

Yes... what was it? �� Having the same issue

 

[Yinzer]

There should be a rule that if you post requesting help with a problem, you have to close the thread with the final fix. I would guess it was the fuel pump that fixed the OP's issue but would like to know for sure.

This would be great.

Found out that when the Walbro (allegedly) was installed, it was installed too far down in the tank and the pickup screen was against the bottom of the tank and bent back upwards.

Does anyone know the part # or proper part name for the fuel pickup screen?

 

[Valhalla]

I don't believe you can purchase a new screen separately, it comes with a new pump. Someone please correct me if I'm mistaken.

Does anyone know the part # or proper part name for the fuel pickup screen?

 

[Old Guy]

I don't believe you can purchase a new screen separately, it comes with a new pump. Someone please correct me if I'm mistaken.

You are mistaken; but, effectively you are correct. Acura does list the suction screen separately. The part number is 1751-SL0-000 and the MSRP is around $65 US$. That has to be the world's most expensive piece of plastic screen and I expect that they don't sell too many. If you hurry, RockAuto has a close out special on the after market Delphi suction screen FS0165 for a nudge over $1.

More Information for DELPHI FS0165

​