KingFish

Can someone tell me where I can find the fuel pump relay on my 85 with a 12a?

I'm having an issue with getting fuel to the carb.
It seems that the fuel pump isn't kicking on. I just picked this car up yesterday and it sat for about 8 months in a barn before I tried to start it. The car fired right up with the choke pulled out and it ran great until it warmed up, then it didn't want to idle. You could keep your foot on the gas and keep it running, but as soon sa you let off the car would die. So I let it sit for 2 more week before going back to pick it up and trailer it home. When I got there the car would start at all. I changed the plugs, wires, cap, rotor, oil, fuel filter, and air filter. Now when I put gas into the carb and it fires right up. I popped the fuel line on the carb and cranked it over and got no gas. I then took out the rear compartment and got to the fuel pump wires. There was no voltage on either wire. This is why I think the relay could be bad, but I can't find it. The previous owner told me he installed a new fuel pump on the car a year ago so I don't see how that could be going bad already.

any help would be greatly appreiciated!!

thanks
Fish

KingFish

No one knows where the fuel pump relay is on an 85 RX7 with a carb 12a engine?????????

cdrad51

under the dash, to the right of the steering column. Little evil black box. Let me know if you need pics. Oh BTW, had you done a search you would have found it without having to ask. Remember, the search button is your friend.

Dom

Body and Electrical, page 11.


http://www.wankel.net/~krwright/cars/rx7/85_manual.html

CarlRx7

took me forever to find it on my 85 12a. right above your right knee as if you where sitting in the car. you dont need to remove any panels just some a/c ducting if you got it.

Carl.

KingFish

thanks for the info guys!! Much appreiciated!!

I did try the search option and came up with a couple threads about fuel problems on 2nd and 3rd generation RX 7's, but nothing on first gen's. I hate redundent threads as much as the next guy......

cdrad51

Hmm, this is what a search on "fuel pump relay" on the 1st gen section gave me:

https://www.rx7club.com/showthread.p...uel+pump+relay

Jeff20B

iTrader: (13)

Yet another '84-'85 fuel pump related problem thread. Hmm.

seanrot

iTrader: (2)

One other little thought to keep in mind is the fuel pump wont work unless the engine is running. Kinda funny PITA but the trailing ignitor sends a signal to the fuel pump. If the enigne isnt running the no signal no gas. I once disconneted the trailing ignitor to try and diagnose another problem. Well, when I went to connect it again the prong missed the connector and my car ran till the carb was outa gas. A day later found the problem. started right up. good luck getting it running

cdrad51

Really? how strange. Fuel pump will run on my car without the engine running. Did the little trick to bypass the relay and so the fuel pump comes on as soon as the key is in the on position. But I don't think it's got anything to do with trailing ignitor.

gsl-se addict

iTrader: (3)

The stock setup will energize the fuel pump whenever the key is in 'START' while cranking or when the key is 'ON' with the car running. This function is controlled by the control unit under the passenger side floor. The control unit does get its running signal from the trailing coil. If no ignition events ar detected within a precribed amount of time, the control unit wil think the car is not running and shut off the fuel pump. The signal from the control unit is used to energize the fuel pump relay which powers the fuel pump.

cdrad51

Oh so that is if the relay is not bypassed. That would explain it.

KingFish

ok I found the relay and it's working. I hooked 12v directly to the pump and beat it silly with a hammer and it kicked on. Now my car will run great until the choke kicks off the it won't idle. It'll start back up with a few pumps of the gas and I can drive it as long as I don't let it get below 1000 rpm.

Any suggestions?

Yea I know..... The search button!

I'm going to do that now....

KingFish

BTW Thanks for the link to EXACTLY what I was looking for! I can't believe I didn't find that.. lol

Anex 570

Rebuild that crudy carb and you will be able to idle.

KingFish

Hmmm Rebuild a carb..... That sounds a little tricky...

Is there any type of cleaner I can spray in there and it magically eats all the crap away?

What would a good replacement carb be? If I can put something else on that's going to give it a little more power that I wouldn't mind just doing that...


thanks

KingFish

after doing a search I found that different hi-po carbs are EXPENSIVE!! haha more than I even paid for the car.

cdrad51

You're learning, you're learning

Try also the 1st gen FAQs

Jeff20B

iTrader: (13)

Sterling carb.

seanrot

iTrader: (2)

Boy I hate being the first to say this......

1. Car runs with choke
2. Car dies without choke
3. Will stay running with the gas pedal not letting go below 1000 RPM

Sounds like the MYSTERIOUS VACUUM LEAK to me

Good luck finding it.

KingFish

Vacume leak I thought of and went thru the Haynes manual to try to figure out a good place to start looking... Where would you suggest me starting? Is there a specific vacume line that would control the idle?
Is there an Idling position sensor or something simialr that could have went bad?

thanks for the help

hornbm

just get a can of carb cleaner and start spraying around the vacuum lines. If the rpm goes up, you've found your leak.