Fuel pump wire...

[onecrazyfoo4u]

I have a 95 with a redtop in it. I put in a walbro 255 several months ago.

Well, since I took out my electric fans, I can finally hear the fuel pump primp when I turn the key. And it primes continuesly, not just for a few seconds like it should. When I installed it, I noticed that the previous owner had run a line from the power line where the fuel pump was, to this hookup or relay by the ecu; It's the big red wire soldered into the black one:





What relay is this? When I unhooked this line and ran just the stock power line from the connections by the trunk, nothing worked. I think the pump bing hardwired in is giving it way too much fuel. I don't need it, I'm pretty much stock running 7psi. Is there any way I can wire just like the factory would?

I think this is the reason my car is so hard to start in the mornings, it's just being flooded by the pump. I have to crank for nearly 30sec. and when it starts, it sputters and wants to die, kind of like a bad head gasket. I've checked several times, no coolant in the cylindars whatsoever. Any other ideas? Please help me out on this one!

Sorry for the long post........

[T-rev]

I have no idea what fuse that is, looks like something random. The stock fuel pump relay is in the fuse/relay combo box box by the battery, its green, 2nd from the left (in between a green and grey relay), its called EGI PUMP on the cover. This relay is controlled by the ecu, ground turns the pump on (pin 104). Theres also a 10A fuse for the fuel pump nearby.

Check the fuse and relay to see if they're still good. They could have burnt, and the previous owner couldnt figure it out, so just wired in a relay. If the relay and fuse are good, I would just hook up the pump correctly.

Test the relay with a test light, have a buddy turn the key ON, the fuel pump relay should come on and stay on for 5 seconds, then shut off.

[onecrazyfoo4u]

Hey thanks alot for the info. Yeah, I can't tell if that's a stock relay, or something they randomly put in. I knew there was a fuel pump fuse down in the drivers side kick panel...didn't know there was another under the hood. I'll check it out tomorrow and get back to you. Thanks!

[onecrazyfoo4u]

Well, I checked and I don't have any relays/fuses for the fuel pump in the engine bay....maybe that's for an s13 chassis? I did find the 104 pin on the ecu for the fuel pump and there's no voltage to it with the key on at all. It's a dead wire, and I don't know where to trace it to, the engine bay? Here's pics of my engine bay fuses:





And here's a pic of the wires coming from my fuel pump. The red wire runs to that relay by the ecu. Is the 2 pin connector the right one for power to run to? What is the 3 pin connector for?



When I turn my key on, the pump just runs continuously, never starts pumping. And I think that's why my car is flooding and makes it so hard to start in the mornings. How can I stop this from happening? Please someone help me!!!

[T-rev]

sorry, big whoops on my part, yes that was for a s13, my bad

on a related topic, I now have a very similar problem as you, except my pump is acting like it should. Im running crazy rich, and it takes like 3 or 4, 10 second cranks to get it to fire up in the morning, and when it does it burn alot of gas, and I mean A LOT, think big cloud of exhaust, you can smell the gas. Are you experience this? I think the root of my evil is the injectors. Your problem may not be the fuel pump constantly running, I thought it ran constantlyanyways after the motor cranked.

Do you have a fuel pressure gauge? If so, whats your fuel pressure?

[onecrazyfoo4u]

Mine takes about the same amount of time as yours does, but I've never seen any smoke or smelt the gas lately. I'm pretty sure it is running rich though, because of the loooonnnngggg starts, but never smell any gas. I don't have a fuel pressure gauge, but I do need to get one. Do you have one? If so, what's psi should it be at? This problem sucks bigtime!

I wish someone else could chime in too that has these same experiences! How do we fix it?

[Steve Lloyd]

that relay in your first pic is your ECU power relay, that's why it stays on all the time. You need to cut the red wire that was added and connect it to the black/pink wire on the SR harness, that's the fuel pump wire.

[T-rev]

I borrowed a gauge, so Ill check my pressure tonight and let you know what its at. According to PDM, stock fuel pressure is 36 psi, http://www.pdm-racing.com/products/power.html

When I start it in the morning, when it finally catches, it idles real low, barly running on the verge of stalling. I have to hop it up to over 1000rpm, then it smooths out and idles fine. Are you experiencing this?

Currently my car is running like crap, lots of backfiring, poor fuel milage, and no power.

[onecrazyfoo4u]

Oh cool, so it's the ecu power relay. I was thinking about cutting the wire and hooking it up to pin 104 for the fuel pump. But then I thought it would do the same thing, since I thought the line is supposed to go to some relay. Would it still work, or just be constantly on like before? Ah, I'll go try it out and see. Thanks for the info!

T-rev, I definitely need to get a fuel pressure gauge too, to see if it's right or not. When I finally get mine started, it instantly jumps to like 1200 and idles normally. The first couple of times I give it gas though, it sputters and wants to die. I'm sure it's just the leftover fuel being burnt out. But I have to give it little taps of gas the whole time I'm cranking too. Let me know how the fuel pressure works out.

[T-rev]

I just tested my fuel pressure, at idle its 43 psi, revving it up, I get a max of 51 psi. I taped the gauge to my windshield and went for a test drive, I hit a peak of 60 psi under boost. Im using a walbro 255 L/hr

I found out part of my problem. 1 injector was dead, so I was basically on 3 cylinders. Also 2 injectors had mangled o-rings so the fuel was just pouring into the head. This explains why it was tough to start. And I was rich on 2 cylinders and lean on the other 2.

You might want to pull out your injectors and see how the o-rings look, check them for nicks and rips. The previous owner has proved his prowess with electrical, maybe he was into the injectors too. Remember to lube those babies up when you put them back in!

[onecrazyfoo4u]

Yeah, I'll have to check that out for sure. Is it pretty easy to pull them out? I've never done it, so I'm kind of wondering if there's a writeup or something to pull them out. Or do you just unbolt everything and yank them out? Do you have to shut the fuel off at all? What do you lube them up with when putting them back in?

I think I'll buy new gaskets anyways....is this the kit that I would want? http://cgi.ebay.com/ebaymotors...ZWDVW

Isn't there a way to test them too? Like you pull them out and switch the key to 'on' to prime the pump, and they should just drip out I think. If they're spraying, then the injector is bad...I believe. Thanks for the info and sorry for all the questions!

[T-rev]

Other than flow testing the injectors I dont know how to testing them, I went to 2 different places and they went set up to test side feeds. That looks like the kit you want, for 20 bucks I think I might pick up a set too.

The injectors are pretty easy to get out, Ill give you a brief writeup.

Start the car and pull the fuel pump fuse or relay, when the car stalls it drains most of the fuel pressure. Unplug all the injectors. Each injector is held in place by an aluminum cap with 2, #2 philips head screws. When you take these out, use a good screwdriver, snap on, craftsman, you DON'T want to strip these screws, and they're in there tight. Once you get the screws out, you'll be looking at the top of the injectors.

Spray carb/throttle body cleaner on the injectors. This dissolves the varnish and loosens the rubber o-rings from the fuel rail. The injectors have a slot under the plug for you to pry them out, but the angle is all wrong, so I used a big pair of pliers and carefully twisted/pulled them out. Throttle body cleaner is the key, it makes the job much easier. The injectors then pop out, any remaining fuel in the rail then drains into the head, dont worry about it.

Look at the smaller o-ring (~3/8" dia) at the injector tip. Look for any nicks or anything sign it could be leaking.

Instalation is the reverse. Use some moly based lube on the o-rings so they slide in without any binding problems. Oil will work in a pinch. Carefully push the injector back into the rail, and you will feel it *pop* into place. The top of the injector will be flush with the top of the rail. None of this, using the screws to pull the injector into place, thats gonna cause you problems. Screw on the caps, plug in the harness and turn on the fuel pump, and give it a start. It may be hard to start since all that fuel dumped in the head, but it will go.