SupSai7

iTrader: (8)

Ok I finally broke down and decided to post. This problem is kicking my ***. I finally installed the walbro fuel pump thats been sittin on my bedroom floor for 3 months, and now my car has been out of comission for almost a week. Before I installed it the car ran great no problems whatsoever. Started up fine everyday, now when I go to start it just revs up then dies after about 2-3 secs. I de-pressurized the fuel system by starting up the car then disconnecting the fuel pump plug located next to the Lft. rear strut tower, then took the gas cap off. Installed the walbro pump on the stock bracket as per instructions, installed it hooked up everything(fuel hoses and fuel pump wiring. I primed the system accordinly by jumpin the yellow two pin connecter on the rt. hand strut tower by the boost sensor/intake.(left it on for almost a minute just to make sure, so I know it's primed). I made sure I heard the relay click and the pump come on. Took off the jumper wire then tried to start it nothing, just starts then dies. I then tried to start it with the jumper wire on nothing same thing starts up then dies WTF!, then I tested to make sure it was shootin fuel out of the outlet right on the pump, it was so thats good. I double checked the polarity it was right, but I tried switching them around anyways, nothing again won't start, so I switched them back the way I had them(I knew it wasn't the right way anyways because I saw it blowing bubbles in the gas). I double checked the fuel lines also, their on the right way(there's no way I could have mixed them up b/c the outlet hose from the pump to the injecters doesn't even reach the return fuel line nipple on the pump, plus the way they are angled). I also checked every fuse on the car they are also good. Even though I didn't mess with anything else under the hood besides the jumper connecter, I checked all vacuum lines and intercooler piping they were all good also WTF!. So I gave up, disconnected my battery and put it on the charger. I did some research on this forum, too see if I screwed something up and to get some ideas. So I came to the conclusion that I have either flooded my car(after trying to start it so many times), or got a faulty pump from the get go. Going with option one I tried to hold the gas pedal while starting it(hey it worked for others) for 4-5 seconds and even longer as I got pissed off more. Nothing it wouldn't start at all just kept cranking. Then I tried to remove the egi fuse, crank it to clear out the gas then reinstall the fuse and try it. Nothing again,(by now I just want to bash everything in sight with a BFH). I don't know why I tried that, my car has never flooded before. Just a blind hope I guess. Now I'm for certain I got a brand new bad pump. Okay 3 days later now and I just want to drive my car and quit bumming rides off people. I put my old stock pump back in hook everything up, jumper wire etc.., try to start it and it fires up!, yea baby!, Uh oh, it dies after about 7-8 sec, okay no prob. better than the last 50 times. Mabe it wasn't primed all the way, try again it will keep running for sure this time, again 7-8 sec then dies. I try again, starts 2-3 sec then dies, try again 2-3 sec then dies. Back to square one. BTW I also checked the stock pumps outlet and it's shootin fuel, but I did notice that if I left the outlet fuel hose line on and disconnect the return line hose it wasn't returning any fuel at all to the tank, is that right? Isn't it supposed to return unused fuel to the tank? Or does it only return fuel while it's running? Somebody slap some sense in me and tell me what I fucked up. Thanks, if you made it this far.

Ernie

Cameljoe

I'm guessing its flooded. Just taking out the fuse and bottom plugs and cranking the engine wont make it start again you need to replace the oil the gas washed away. This time add some ATF (Automatic Transmission Fluid) to the 2 lower plug holes after you gotten the excess fuel out. Then crank the engine so the ATF can work its way around. Put back the fuse and 2 plugs. When it starts its going to smoke alot. This is normal. Just keep your foot on the gas till the smoke clears and the engine has reached operational temp. before shutting it off.

TonyTurboII

You might want to disconnect the hose between your fuel filter and the fuel rail. Act like your priming the system, and see if you get fuel that far. If you do you know its not the pump. If you dont you know its somewhere behind that point. If it turns out fuel isnt getting that far, you might want to take the pump out, and hook it to a switched 12v source, and set it in a gas can to watch the results.

HAILERS

My first thought is that, yes it should return the fuel to the tank. That's why when you jumper the plug on the r/h strut, you can hear the bypassed fuel hissing and returning to the tank. Just the first thought. Second thought is to put a fuel pressure gauge on the output from the filter. Either there is something stopping up the return or you have one weak fuel pump.The pump puts out something like 80psi. Regulator regulates to 40psi, and you have no return so the pump would have to be putting out less than 40psi. Or you did not have the jumper in to run the pump when you took the return line off, which you know you did not do.

jspecracer7

when I installed my rp competition fuel pump in, my car did something very similar. It started and ran for about a day, then all of a sudden it would do that. Go buy some new spark plugs, then take out the lower plugs out and de-flood the engine. After that, put the fuse back in, and put in the new spark plugs(just go buy 4 X bur9eq leadings...they work fine and will last you a little longer) and fire your rex up!

I'm praying it works anyways

SupSai7

iTrader: (8)

Thanks for the reply's guys. I'm gonna try to get ahold of a pressure gauge and see if it's puttin out enough pressure. But if it isn't that means I have two bad pumps. I'm gonna check the spark plugs and make sure their fine. Mabe add a little atf in lower holes. I'm also gonna try to take the fuel hose off of the fuel rail and check to make sure the fuel is gettin that far. Wish me luck. Thanks again

Ernie

HAILERS

Doubtful that its two bad pumps. How about disconnecting the return line at the engine, and blowing back into the tank or back towards the tank with the return line off the pump??

SupSai7

iTrader: (8)

HAILERS-
Yea thats what I'm thinking, thats a one in a million chance that I got two bad pumps. One that worked before I pulled it out(stock), and the brand new walbro. Now, there is one thing that I didn't replace, the fuel filter. I bought the new filter when I got the walbro and was gonna change it when I did my next oil change. Which I do on a lift. So it would be easier. But now I'm gonna change it outside in the cold with jack stands.This sux, is there anyway that mabe the internals of the filter broke down with the pressure of the walbro and mabe clogged the fuel line? I know I should have replaced the filter when I did the pump, but I was replacing the pump while I was at my friends house in his driveway. For some reason I don't think it's the filter, but I'll try anyways. I'm gonna work on it tonite and let everyone know the results.
Thanks again Ernie

SupSai7

iTrader: (8)

Replaced the fuel filter, made sure the fuel was making it that far and it was, I also made sure it made it to the pulsation dampner and it was. Replaced plugs, I took out the lower plugs first though and turned it over. It had plenty of compression, so I decided not to use the atf. So I just turned it over with the fuel pump disconnected, just in case. Replaced all the spark plugs with new ones and tried to fire it up, nothing. Try again. Whats next? Anybody?

Maxthe7man

I am gonna go out on a limb here and say look at the turbo inlet duct and check it for a crack or leaks, then make sure the airflow meter plug is tight.. Other than that I would check to make sure the fuel pump is getting the required voltage.. Other than that I would have to say that you may have a bad hose connection inside the tank, which means you would be spraying alot of gas around in the tank, but sending very little up to the engine, another possiblity is the ground wire for the pump is not connected well...Max

HAILERS

Disconnect the fuel pump. Buy a can of Starter Fluid. Spray into the snorkel. Start the car. If the car starts for a moment, repeat the process. If it continues to start for spurts when spraying the starter fluid, then you have a sure fire fuel problem. If you get not momentary start of the engine, then we need to look at the spark, timing issue side. So fuel is getting back to the tank now?????? On the return line???????EDIT; This is starting to bug me. How about pulling the lower plugs and ALL THE WIRES OFF ALL THE PLUGS, and with the fuel pump connected and everything else, have someone turn the engine over. You should get a more than obvious mist out of the plug holes indicating the injectors are injecting. It should be a fog of fuel mist. None of this *I think that might be fuel* stuff. Some people do not like doing this, citing chance of an explosion due to the fuel mist and the sparking plugs. Fiddlesticks, I say. At least you can determine if the injectors are working.

Mines RX7

The first thing I would check would be the pressure coming out of the pump. Make sure that is high enough to work. If you've done that and it still doesn't work, maybe try resetting the ECU? I'm kind of reaching for anything after reading this thread. Are the injectors stock? If their stock then they shouldn't be injecting TOO MUCH fuel, but that might be what's causing the flooding. These are just suggestions, I don't know for sure man.

dave007

iTrader: (1)

Is your car Turbo or NA?

SupSai7

iTrader: (8)

No, the fuel is still not returning to the tank, but then again we don't know for sure if it should so I still don't know if thats the problem(btw I checked w/ and w/out the jumper wire connected). I still haven't tried to blow into the return line at the eng., and check to see if air comes out at the tank, fuel pump. Also when I had the lower srak plugs out I turned the eng. over w/ the fuel pump connected and it DID ignite and sent some blueish flames out of the spark plug holes.As per my friend who was standing there and wacthing the lower holes. So I know it's combusting but it's not sustaining the combustion, only for a couple of seconds, probably like 2-3 secs,since thats what my car has been doing all along. For everone else it is all stock execpt for the mods I have on my sig. on the first post, and it is a turbo. Thanks again.

Bambam7

It sounds to me like you car is only using the fuel that is pressurized in the line.
So, I think the pump is only running while the ignition is on, and while the engine is cranking, but shuts off as soon as the engine is running. If you have already determined that and I am a day late- sorry, All those last posts were too long for my lazy dyxlexia!!

My guess- Your fuel pump resistor relay is malfunctioning

The resistor relay drops voltage to 9 V under idle and cruise to lengthen the life of the fuel pump, when it's not needed.

I believe installing a pump that draws more current very well could have fried the resistor relay. Current doesn't go through it while cranking or at heavy throttle. I bet you that if you could somehow be driving your car at full throttle, it would be fine, but as soon as you hit idle or light cruise, and the resistor flips on, it would die


If I were you- I would take a live 12v line from somewhere, and pop it on the pos terminal for the fuel pump (I know, I'm an unsafe idiot), so the pump is running (turn the ignition on first)

***Make sure you hook the wire up to the fuel pump FIRST, then to the battery or whatever, so any sparks are away from the pump.***
See if the car starts and runs- I don't know the wiring for the pump, but if it runs, at least you can determine that is probably the resistor, or other wiring prob.
There is a test in the factory service manual.
The resistor is under/behind the passenger headlight- aluminum box with a heatsink. You can bypass it by jumping the wires at the clip. No harm done- Even if it tests fine- you might want to try it anyways.

Let me know how my shot in the dark is- It makes sense to me.

HAILERS

I'll make the ultimate sacrifice when I get off work and verify that the flow should return the excess pressure to the tank. Just know it should. Thats how it regulates the pressure from a delivery pressure of 80psi down to 37 at the rail. Bleeds off excess of 37 and dumps it back in the tank. There is no pressure sw in the system that shuts the pump off when it hits 37.

ghebert

Just a thought any chance you connected your fuel line wrong? I did this after replacing my engine. The hard fuel line criss cross under the manifold. The line from the fuel filter goes to the primary fuel rail, the secondary fuel rail goes to the return. Hope you figuere it out. Gary

HAILERS

Just got home. Front hard line on the engine goes to the fuel filter. I took off the rear line and attached a line to it and put it in a container. Turned the fuel pump on for one minute. The return line(rear hard line) put 900ml into the container after one minute. Put my mouth to the return line going to the tank and blew. It was restriction free except for the gas that was in it that went into the tank. So indeed, with the fuel pump on, you should have gasoline at the rate of 900ml per minute going back into the tank. Also put the fuel gauge on the pressure line with the return line hooked back up. Just the pump running I get 40psi. Turn the engine on and the regulator drops the pressure down to 32psi. I suggest taking that rear line off at the engine, and blowing back into the tank. It should be restriction free.

SupSai7

iTrader: (8)

HAILERS- Thanks alot for doing that, so it SHOULD return fuel to the tank great. Now all I have to do is blow into the return line and see what happens. So I narrowed it down to either a blockage in the return line, Or what BamBam7 mentioned the fuel pump resister relay, that just might be it also if the pump is putting out fuel but not getting enough volts to put out enough pressure, I seen that it was pushing fuel out so I thought it was fine. I'm going to get ahold of a good voltmeter at work and also get a fuel press. gauge, and test everything. I'm going to try everyones suggestions. I can't work on it today b/c of rain but I should be able too tomorrow morning.(I work graveyard shift). I also need too find something to measure the amount of fuel coming off the return line also, I'll check that so it should be around 900ml per minute. I appreciate the help hopefully I can get it to start.

HAILERS

Well one thing I remember is you had that plug on the r/h strut tower jumpered to run the fuel pump at one time, so that more or less told me the relay was good. And at one time you saw the fuel flow into the tank with the plug jumpered. I think, before I spent any more money, I would take the fuel hose off the front pipe on the engine(the one that comes from the filter, and stick it in a bottle. Then turn the key on and jumper the connector on the r/h strut tower. If you get good flow, put that line back on, and take the return line off that is next to it. Hook a hose to that hard line from the engine(just let the hose you took off lay) and jumper the plug on the r/h strut tower. You should get a good flow from the direction of the engine.. If that works, then somehow blow into the line that returns fuel to the tank. Should get some slight resistance from the leftover fuel in that line but should flow easily after that fuel returns to the tank. Should hear bubbles in the tank. Darn and shucks, if all that works the drat caar should be starting.