Fuel pump mod???
09-25-02, 09:13 PM
#1
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Fuel pump mod???
CALLING ALL UNITS!!!!!!!!!!
I met this guy that said he removed the check valve from the fuel pump so that the car won't flood at startup. He said it works... I don't know... Any comments on this will help many people.
I met this guy that said he removed the check valve from the fuel pump so that the car won't flood at startup. He said it works... I don't know... Any comments on this will help many people.
09-25-02, 09:40 PM
#2
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the check valve that goes to the charcole canister? what would that have to do with flooding, it doesnt even go the the injectors or any of that
09-25-02, 09:50 PM
#3
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I don't know what check valve. Does the pump have one inside? He was talking bout not having pressure at the fuel rail at the moment of startup. I know nothing about the inside of the fuel pump.
09-25-02, 09:57 PM
#4
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This is a bad idea but I'm sure it works if the hot-start is due to leaky fuel injectors ONLY...
The check valve in the fuel pump keeps pressure in the fuel rail to prevent the fuel from boiling off and 'vapor-locking' the motor. If you have a leaky injector, it leaks down this maintained rail pressure and washes down the rotor. Without oil the rotor won't seal and then you have a no compression hot-start.
Removing the check valve will result in no rail pressure and subsequently no leaking of fuel into the motor. It also allows what fuel does remain to boil off and vapor-lock the rail. Now you'll have a long cranking fit to get the pressure back up.
Not much of a solution in my opinion
The check valve in the fuel pump keeps pressure in the fuel rail to prevent the fuel from boiling off and 'vapor-locking' the motor. If you have a leaky injector, it leaks down this maintained rail pressure and washes down the rotor. Without oil the rotor won't seal and then you have a no compression hot-start.
Removing the check valve will result in no rail pressure and subsequently no leaking of fuel into the motor. It also allows what fuel does remain to boil off and vapor-lock the rail. Now you'll have a long cranking fit to get the pressure back up.
Not much of a solution in my opinion
09-25-02, 10:08 PM
#6
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If I recall, Mazdaspeed 7 mentioned this. It's on the solinoid rack. After removing everything he said that he couldn't get his car to flood no matter how hard he tried. I could be wrong tho. Ask the man.
09-25-02, 10:17 PM
#7
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The check valve that maintains the fuel rail pressure is inside the fuel pump.
Up on the 'rack' is a soleniod that will temporarily increase fuel rail pressure (on S5 cars at least) during cranking. It does this by disconnecting the fuel pressure regulator from the manifold and preventing the vacuum signal from the manifold from lowering the fuel rail pressure.
Perhaps this is waht you're after?
Up on the 'rack' is a soleniod that will temporarily increase fuel rail pressure (on S5 cars at least) during cranking. It does this by disconnecting the fuel pressure regulator from the manifold and preventing the vacuum signal from the manifold from lowering the fuel rail pressure.
Perhaps this is waht you're after?
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09-25-02, 10:26 PM
#8
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Actually he gave me the fuel pump to try. I just want to know if the check valve can be put back in. I got a dead TII pump at home.
09-30-02, 05:19 PM
#16
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I hate saying it, since the Fuel Switch is a really rigged mod that screams "I can't fix the real problem, so I'll work around it", but the switch actually does serve it's purpose VERY well. I haven't had any probs with mine after installing a switch, but it still seems like the "using a 30A fuse cause you keep blowing 20A fuses" fix.
09-30-02, 05:30 PM
#18
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Yes, it's a band-aid, but if your engine does flood (and it will), at least you won't be caught in the rain or some similiarly bad position.
I run 4x720's and my engine will still flood on a very hot day.
At least the switch doesn't inconvenience me in any way like the other methods I used to use (pull fuses under the hood, pull fuse in the kick panel, pull relay on steering column).
A $2 switch and some connects makes it a $5 job and an hour of your time.  Very cheap considering your other options...
-Ted
I run 4x720's and my engine will still flood on a very hot day.
At least the switch doesn't inconvenience me in any way like the other methods I used to use (pull fuses under the hood, pull fuse in the kick panel, pull relay on steering column).
A $2 switch and some connects makes it a $5 job and an hour of your time.  Very cheap considering your other options...
-Ted
09-30-02, 06:35 PM
#19
Originally posted by RETed
A fuel pump cut-out switch will cure almost ALL flooding problems without breaking the check valve out of the fuel pump.
-Ted
A fuel pump cut-out switch will cure almost ALL flooding problems without breaking the check valve out of the fuel pump.
-Ted
Never flooded after that and even still, the Fuel Pump Cut of Switch acts as a great securuty measure.
09-30-02, 09:17 PM
#21
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My car does not flood at all ever!!! I just need a TII pump and he gave me this one. I got 550 primaries and 720 secondaries on an 87 n/a turbo engine, auto tranny and ecu. I just wanted to know what was up with that check valve thing.
09-30-02, 11:20 PM
#22
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the security measure I won't argue with, but since my car has never had any threats of theft, I'm not that worried about it. I have a Viper alarm that's only armed when I accidentally hit the button in my pocket, so it's not that great of a bonus. However, if it's used for anything other than a theft device, then it's merely a "lazier" way of pulling the fuses under hood. Not that I'm knocking it, since I use it myself but I'm just saying it's really rigged and the real problem needs to be addressed.
To Angel Guard... I don't believe the check valve will make much difference, and like was mentioned earlier, the pressure related explanations are the same reason I'd use.
but I'm just saying it's really rigged and the real problem needs to be addressed. To Angel Guard... I don't believe the check valve will make much difference, and like was mentioned earlier, the pressure related explanations are the same reason I'd use.
10-01-02, 12:19 PM
#23
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the security measure I won't argue with, but since my car has never had any threats of theft, I'm not that worried about it. I have a Viper alarm that's only armed when I accidentally hit the button in my pocket, so it's not that great of a bonus. However, if it's used for anything other than a theft device, then it's merely a "lazier" way of pulling the fuses under hood. Not that I'm knocking it, since I use it myself but I'm just saying it's really rigged and the real problem needs to be addressed.
To Angel Guard... I don't believe the check valve will make much difference, and like was mentioned earlier, the pressure related explanations are the same reason I'd use.
To Angel Guard... I don't believe the check valve will make much difference, and like was mentioned earlier, the pressure related explanations are the same reason I'd use.
10-01-02, 01:08 PM
#24
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Lol, I actually bought my first TII by selling "modified fuel pumps" when I was 17to 18. I did the mod on my first rx-7 vert, because I couldn't get it to stop flooding and I wouldn't ghetto rig a damn switch to my injectors and clear it whenever the car flooded. People said to do everything from hook up some purge thing that let pressure off the fuel system sold by Mazdatrix, to hooking up the ghetto switch. Since my dad and I had dealt with an injector leak on an old project 240Z w/a v8 by removing the pressure valve on the pump, I gave it a try. It worked great and my car never flooded again. Yes, the car will take a second longer to crank, because it has to build up to the 35 or so psi maintained by the stock fuel system. If you can tell that it takes longer to crank, you have issues. I would bet that you couldn't tell a differeence when cranking my TII Convertible with a modded FD pump and another TII.
To do it just take the pump out of the car and get some needle nose pliers. Then rip the little plastic looking basket thing out of the fuel pump opening.
You won't be able to put it back in. Really, you'll break it pulling it out.
This will save you from the embarrassment of have to clear your motor with that ghetto "theft detterent" switch, and you won't leave a big plume of white smoke when you get the car started.
Some people may not like this mod, but to all their own. I would only have a switch like that in a car that I didn't have passengers in. Both are patches instead of solutions, one just doens't require any intervention or maintenance.
PM me if you have any questions or issues.
To do it just take the pump out of the car and get some needle nose pliers. Then rip the little plastic looking basket thing out of the fuel pump opening.
You won't be able to put it back in. Really, you'll break it pulling it out.
This will save you from the embarrassment of have to clear your motor with that ghetto "theft detterent" switch, and you won't leave a big plume of white smoke when you get the car started.
Some people may not like this mod, but to all their own. I would only have a switch like that in a car that I didn't have passengers in. Both are patches instead of solutions, one just doens't require any intervention or maintenance.
PM me if you have any questions or issues.
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