cuate

i have a 93 rx7 and im having a problem with the fuel pump and the injectors when i put the key like im going to start the car the pump goes on and doesnt stop as the injectors pursh gas in and floods the motor and i dont know what to do if any body has and answer let me know thanks

Tim McCreary

Do you have a manual? If not start here. How mechanically inclined are you:
http://www.wrex-racing.com/web/fd/info.htm

First, Determine if the mechanicals are working properly, check the pressure regulator at the end of the fuel rail going to the return line, check the inline fuel pressure. Determine if the fuel injectors are leaking (most likely the cause). You can make an inline fuel pressure tester by taking a brass barbed Tee. Run two small fuel lines onto it, one up to a pressure guage. I just made one a few days ago and it works great. I got a 60psi pressure guage for $9, brass tees for $5, and a barbed fitting for the guage for $1. You might want to opt for a higher pressure guage like a 100psi since there may be an issue with high pressures. Do a leakdown test also.

Email me direct at mccreary1@atlanticbb.net for a picture of my setup.

Next, look for the wiring diagram for the fuel pump. Trace and find the relays involved with the fuel pump. Determine if the fuel pressure switch is working properly. There is also a step resistor that changes the voltage to the fuel pump. It may have failed.

Good luck.
Tim

Mahjik

iTrader: (1)

Your injectors shouldn't open until you crank the car. Is your fuel system and ECU stock, or is it modified? Describe your system for us.

cuate

My bad guys, new to the forum . My car is a 93' twin turbo, automatic, all stock. let me better describe the problems. when I first turn on the key the fuel pump stays on and the injectors stay on at the some time. You can hear them spraying continiously. Here is what Ive done to find out what the hell happened. If I take out the fuel pump relay out , and crank the engine to unflood it, then connect it, then clean the spark plugs. Car will start breafly then flood it self out. I am mechanicly incline, but will admit that its my first rotory Ive worked on. There u have it any ideas, I think it might be the ecu. ANy body know any shops that work on RX7's here in vegas. Any help would be appreceated. THANKS.

cuate

Bump to top. Sorry guys really trying to find the problem on my car. Seems that there is no shops that work on RX7's here in vegas. Budget kind of tight to take it to the dealer. If it is the ecu, I cant seem to find one for an auto, how hard is it to swap to a manuel tranny. I could get my hands on a ecu, and tranny from a guy that did a ls1 swap in his. any idea what else is involved and were I could find the pedal asembly. thanks

rxrotary2_7

sounds like you need to injectors cleaned if they are sticking open. Send them in for cleaning service: http://injector-rehab.com/

Mahjik

iTrader: (1)

As rxrotary2_7 mentioned, your first steps need to be either or both:

1. Test the injectors by sending 12V to them and listen to hear if they click
2. Remove the injectors and send them out for cleaning and flow balancing

If you have someone local with an auto, you can try to swap ECU's to see if it is an ECU problem. However, injector problems are far more common than ECU problems so I would place my bet there. It could also be a wiring problem as the emissions harness (the part of the harness which connects the injectors to the ECU) is prone for getting brittle from the underhood heat over time.

Basically, you need to break out the tools and start testing or removing stuff if you don't want to take it to a shop.

dgeesaman

iTrader: (7)

Those guys ^ are right. I'd start with the 12v test, and if you get clicking, go another step: Remove the TB, UIM, coil pack, ACV, and solenoids. Unbolt the fuel rail and carefully lift it up of the block a little bit. Make sure all fuel lines are still connected ok.

Now go the diagnostic box between the fender and battery and jumper the terminals FD and GND using a paper clip. Turn on the ignition - this will circulate fuel. If one of the injectors leaks, remove them and get them cleaned.

Another thing you can do is repeat the click test (I used a 9v battery and long wires to stay clear of any fuel vapor) and observe the injector spray pattern. I had an injector not working right that would shoot a stream of fuel instead of a spray. That's another sign you need them cleaned/flow balanced.

You can also test your fuel pressure this way, although if you're flooding the motor I suspect it's not for a lack of fuel pressure.

puma

iTrader: (2)

dgeesaman meant FP and GND, not FD.

Also, if the fuel pump runs when you put the key to ON, i would try an other ecu as the fuel pump shouldn't run until the car is cranking i beleive on stock ecu. Combined with injectors stuck opens, i would suspect an ECU.

Also, removing the fuel pump relay shouldn't unflood it as the fuel pump should still be working since the relay is only to make it run on higher speed, the fuel pump can still work with the resistor. To stop the fuel pump completly, you need to remove the green relay in the box on the driver side fender. What this mean is that even if you remove the fuel pump relay, the pump will still run but you would miss fuel in higher rpm or bigger load since it would be stuck on slow speed.

cuate

What is the chances that all four injectors would get stuck open at the same time. or why the pump and injectors stay on with the key in the on position. Or will the pump stay on because the injectors are on and not building up pressure to prime the fuel line.
Man, if I could find someone here in vegas with an auto I would swap the ecu to check mine. but cant find any only manuels is the automatics alot more rare.

Mahjik

iTrader: (1)

You should go here:

http://www.vegasrotary.com/

and see if you can get some local help. We can't do anything here unless you start removing and testing stuff. We can shoot the breeze and guess about what could or couldn't be the problem. However, at the end of the day, you are going to have to start eliminating things which aren't the problem by getting your hands dirty.