Shadow 88' RX-SEVEN

So I am having some problems with my RX-7 still. I replaced the fuel pump, cause there was no pressure getting to the fuel rail, I tested the fuel injectors hat were in the car and also replaced those cause they were not reading any Ohms, so i also replaced them t. I tested the injector plugs with noid lights and when I crank the motor over the noid lights arnt flashing. So What is my problem? Is there not power going to the injectors or is it my ECU? The car will run in primed with gas and will run off a bottle for a while until you take the fuel away.

nicdchris

iTrader: (1)

The fuel pump is on a relay that turns it on when the system is cranking and when the engine starts gulping down air. It doesn't turn on or prime like many other cars with just the key in the 'on' position.

You can trick this system by opening the MAF with the key on. This will turn on the fuel pump for testing purposes. I used a hammer as it was too heavy to get sucked into the engine.

I think it was a bad idea to replace the injectors if you couldn't even get fuel to the rails.

Shadow 88' RX-SEVEN

So how do I jump the fuel system, seeing how i am new at this whole now electric wiring system. I am use to older cars (1900's to 1970's) with just a carburetor. So what is the MAF? And yes the fuel was getting to the rail after I replaced the pump. The previous owner I got it from said the fuel was never making it to the rail and never seem to crank over with fuel getting to the rail. So I replaced the pump and it sure in making it to the fuel rail now.

satch

iTrader: (1)

So now you have fuel to the rail. And what is your current problem? And are the EGI fuses in working condition?

Shadow 88' RX-SEVEN

I don't know exactly where EGI fuses are. Are those the fuses by the wheel well strut? And my current problem is that the injectors aren't getting the signal ,i am guessing, to squirt fuel from the rail into the intake. So its still the same problem. Not sure if my connectors are bad or that the injectors are bad. I know the injectors should be good cause they're brand new.

satch

iTrader: (1)

Yes, they are by the battery. And check the 15 amp Engine fuse (interior)

Shadow 88' RX-SEVEN

And that would be under the dash? And how can i tell which 15 amp it is? I well be on later I have to go to class and take an exam and i will be back home around 5 or so & possibly out side with my laptop if it stops raining.

satch

iTrader: (1)

The fuse panel has a diagram on it to tell what is what and the FAQ section has a pic of the diagram. It's the third row from the bottom and the second from the left situated between a 10 amp fuse and a 7.5 amp fuse.

Shadow 88' RX-SEVEN

Alright thanks Satch! All do that when I am done here at school

Shadow 88' RX-SEVEN

Okay i checked the fuses under the dash. The fuse doesnt look blown so its not that. But there is a fuse under it thet looks to be missing.

satch

iTrader: (1)

How did you go about testing for fuel at the primary rail?

Shadow 88' RX-SEVEN

Took the return line off and cranked the engine. Put a glass jar under neath to catch the fuel. And was squirting the fuel out of the rail. But when i put it all back together its still not starting. I un connected the fuel rail and the injectors and cranked it over and the fuel rail is free flowing the gas out where the injectors go so i still dont know. Im still thinking its the injectors not letting the fuel go in to the intake.

satch

iTrader: (1)

And which fuel rail did you remove to test for fuel flow. Was it the one on top or the hard to access rail? If you removed the primary rail and removed the injectors and had fuel flow out the openings then you need to test the injectors themselves.

Shadow 88' RX-SEVEN

Yes i tested the primary rail. And the injectors are new so they should work. So i don't know where to go from here cause i tested the injectors them selves and they were reading 2 or more ohms. So i dont know if its the connectors?

nicdchris

iTrader: (1)

The injectors should have power when the key is on, pull one of the secondary injector's clips and see if either of the pins in it have power (ground to engine/frame, hot in one of the pins)

If that checks out, then you might want to start pulling up the passenger carpet and kickplate and checking the ECU to make sure it is grounded/plugged in correctly.

If you ask REALLY nicely i'll pull my good ecu and drive down there this weekend and help you sort it out. I'm up in Spokane. PM me.

satch

iTrader: (1)

Your car was designed for high impedance injectors and not low impedance. You have the wrong injectors. Early 2nd gen's were low impedance and this changed during 1987.

Shadow 88' RX-SEVEN

I got the same model injectors as the previous from bostech. I might need help. The previous owner stripped the interior and so I pieced it back together as best as I could. I know I can also access the ECU behind the kickplate. I will check that out tomorrow after i get home from school tomorrow in the morning. Thanks for the advice. I will see what happens and tell you guys what happens. And if i do have more problems I would be glad if you came down and looked at my car.

satch

iTrader: (1)

If your car has the Resistor Box wired into the Emission harness or there are individual resistors wired into the injectors then they would need to be low impedance injectors, otherwise they would be high impedance injectors.

Shadow 88' RX-SEVEN

I don't see any other injectors? other than the main injectors them selves. are they under the throttle body?

satch

iTrader: (1)

I'm not sure which injectors you refer to as there are the primaries and the secondaries. What I am trying to point out is the early 7's had low impedance injectors (2-3 ohms or so) and that was changed during 87 when Mazda switched to a high impedance injectors (11 ohms or so). The low impedance injectors require resistors to change the impedance so they would work properly. 88 and later models do not require these resistors. The Resistor Box came from the factory but some individuals will have to wire in resistors when they are involved in switching engines from series to series.

misterstyx69

iTrader: (142)

there are Two fuel rails and 4 injectors.
One rail that you can plainly see is the SECONDARY rail,located roughly under the top manifold.(BUT it is bolted on the inside of the lower manifold,and injects into the lower manifold)
The PRIMARY rail is located on the engine,in that space between the lower manifold and the engine.If you follow the fuel line from the Filter to the engine it will lead you to it.
The rail sits on the engine itself.Injectors inject into the engine keg itself.

Shadow 88' RX-SEVEN

Well I am going to start taking the throttle body off and see if I can get to the secondary injectors and see if there is any problems their. All do that trough out the week seeing how I have finals this week.

nicdchris

iTrader: (1)

leave the throttle body attached to the upper intake manifold and unbolt the part of the intake where it meets the part of the intake that goes into the engine.

Order a gasket for that now from mazdatrix, they ALWAYS fail when you pull it apart.

take some masking tape and label the vacuum lines as they come off (you don't have to pull them all the way out, just get them out of the way)

You'll need a 10/12mm socket/wrench and at least a 3 inch extension. Keep the bolts in order.