1983 Mazda RX7 GS - new clutch needed and think fuel pump is going

Spectre

The Deported
Joined
Feb 1, 2007
Messages
36,774
Location
Dallas, Texas
Car(s)
00 4Runner | 02 919 | 87 XJ6 | 86 CB700SC
His car should be carb'd. Mazda didn't move to fuel injection until '84 or '85.
I am aware of that, but I was giving more general info with that statement. Too low a voltage can cause a carbureted car to not start, but a fuel injection car is even more susceptible to the problem.
 

Spice_Rack

Active Member
Joined
Mar 11, 2007
Messages
188
Location
Boise, Idaho - USA
Car(s)
2004 Nissan 350Z Roadster, 1983 Mazda RX-7 GS
Thanks for the responses guys... I think my problem may be fuel related because I got the car to start by removing the fuel check valve. I took it out and put the hose from the carb going into a glass jar. As soon as that hose was disconnected the engine seemed like it wanted to start. After a few tries I got the engine to run... after about 10 seconds of running fuel started coming out of the hose. I put it all back together and it is starting ok now, but still feels a little hesitant even on warm starts. I have to give it a little throttle to get it to start which I never had to do before on warm starts.

Now I think there may be some electrical problem somewhere because when the engine is running, alternator output voltage is about 14.5, but shutters and drops for an instant very frequently. Using a voltmeter I see the voltage jumping around... I've seen 9, 5, 4, and even as low as 1 volts. It is jumping constantly and at no point is holding 14+ volts for more than a second or so. I get the same reading at the battery, but about 13.6 V when the engine is running... it also is jumping around and I see the same drops to low voltage while the engine is running.

I tried to adjust the tension on the belt but that didn't seem to make a difference. It is an old belt but there are no cracks... there is about 1.5-2 cm of deflection when I press hard with my finger on it. It probably should be replaced but i'm not sure if this is my irregular voltage problem. What do you guys think?

Again as for the starting issue I don't think its electrical, I didn't touch any electrical stuff to get the motor to start, all I did was remove the fuel check valve and its hose, start the engine, then reattach it. It is as I said starting ok now if I give it a little throttle.
 

Spectre

The Deported
Joined
Feb 1, 2007
Messages
36,774
Location
Dallas, Texas
Car(s)
00 4Runner | 02 919 | 87 XJ6 | 86 CB700SC
You probably have one or more bad engine grounds. Check, clean and/or replace them.
 

Spice_Rack

Active Member
Joined
Mar 11, 2007
Messages
188
Location
Boise, Idaho - USA
Car(s)
2004 Nissan 350Z Roadster, 1983 Mazda RX-7 GS
Well the damnedest thing... it was a loose ground, a big one. I don't know how i missed it because I was under and above the car at least 10 times trying to find it. A buddy of mine was over looking and just happened to look in the engine bay and spotted it. Needless to say it was a moment of pure happiness, and anger, mixed into one strange sensation.

Anyway, the missing ground is now hooked up properly and everything is running good again. System is charging the battery and its starting right up. Now only problem left to sort out is the engine cutting out when WOT in 2nd gear or higher.

Thanks for the help guys. You had the right answer I just didn't find it on my own.
 

Spectre

The Deported
Joined
Feb 1, 2007
Messages
36,774
Location
Dallas, Texas
Car(s)
00 4Runner | 02 919 | 87 XJ6 | 86 CB700SC
Well the damnedest thing... it was a loose ground, a big one. I don't know how i missed it because I was under and above the car at least 10 times trying to find it. A buddy of mine was over looking and just happened to look in the engine bay and spotted it. Needless to say it was a moment of pure happiness, and anger, mixed into one strange sensation.

Anyway, the missing ground is now hooked up properly and everything is running good again. System is charging the battery and its starting right up. Now only problem left to sort out is the engine cutting out when WOT in 2nd gear or higher.

Thanks for the help guys. You had the right answer I just didn't find it on my own.
It's amazing how well things work when they're plugged in properly. :p :mrgreen:
 
Top