Fuel pump problem- help needed!
 

1984-12A

My story:

The other day I had a battery cable problem. Got a jump. Got home no problem. Left car running while I cleaned batt terminals and tigtened cables. While doing so (successfully) the engine died. Unable to start. Poured a little fuel in carb and started but died when that gas was used up.

Found that with ignition on ,no sound from fuel pump. Removed it. Checked it by connecting directly to a battery. Works. There does not appear to be any current flowing to the pump when the ignition is on as evidenced by hooking the pump back up. Didn't make a sound. Tried a new pump with same results.

What am I missing here? In the manuel I see reference to a "pump cut relay". I have no idea what or where that is. Could that be my problem? Sure would appreciate some advise from the forum. TIA

peachpitter

You can make a short jumper wire on your fuel cut relay,(under dash, right of steering wheel) to make it run, but it should be replaced for safety. I will post a diagram tomorro, if nobody else does.

:withstupi

The following thread might help with that

https://www.rx7club.com/1st-generation-specific-1979-1985-18/84-85-fuel-pump-relay-trick-273215/

Yet another...

You guys are the GREATEST! Thanks-will check out the relay
 

Eom

Well as a remider to all. on 84-85 12A cars, the fuel pump doesnt work in ign on. Its a simple logic circut. The conditions that need to be met so power goes thru the relay are as follows.

ign in start position (car cranking) OR
ign on and engine running.

correction: when you turn the key to the on position, the pump will work for a few seconds. IF then the engine is not cranked, the fuel pump will stop. That's the function of the relay, AFAIK.

I don't know if that's right or not. My fuel pump is very loud and I have never heard it kick on when turning the key to the "on" position (85 GS). But what you said makes sense to me as a mechanism for getting the fuel system primed up before the engine is started (possibly quicker starts and therefore less tear on the engine.) But I'm probably talking out of my ass.

I haven't had any success finding that relay
 

to the right of the steering wheel. I will continue to look. I did find a relay under the hood on left side along side the Check relay that is promising but the terminal pattern is not exactly as shown in Haynes.. Any comments or advise?

Peachpitter

did u look at the thread referenced above? if you follow the drawing in that thread, it's impossible to miss it.

Have you checked your fuses?

Yes, checked the fuses

I wonder if it could be mounted in a different location depending transmission type. I wouldn't think so since I would think the desired place would be as close to the keyswitch as possible. I have a manual tranny and it was exactly where the diagram had it, which also showed a manual.

Digital camera is dead so I can't post a picture. It's held in place by a small tab with a 10mm bolt (I think). It's covered with a vinyl-like wrapping with probably 4-5 wires going to it. You probably will not see the relay shown in the picture on that thread because it is wrapped, or at least mine was. Crawl under the driver's side dash and look up towards the direction of the console.

Hope that helps... But probably doesn't... :confused:

Ok. Here's some pics of where it should be. Notice the a/c duct is removed.

http://img.photobucket.com/albums/v2...3-1327_IMG.jpg

http://img.photobucket.com/albums/v2...3-1328_IMG.jpg

http://img.photobucket.com/albums/v2...3-1329_IMG.jpg

http://img.photobucket.com/albums/v2...3-1330_IMG.jpg

Notice that mine is not hooked up, but wrapped in electric tape. It has the permanent bypass, so no relay per se, just the connector.

And the relay looks like this:

https://www.rx7club.com/attachment.p...chmentid=60544

It lives ! Using a mirror I was able to spot the relay
 

and by removing the AC duct was able to jump it successfully. had One misstep when I had the pump leads connected in reverse but that was quickly rectified.

Took it for a test drive. Guess what? Tac doesn't work. Makes me remember something I read on a previous thread about the Control unit being the cause of my pump problems thru its influence on the pump relay.

I hate to keep bothering you guys but anyone have a fix for my tachometer? And if it has something to do with the control unit- where is it and what do I do? Thanks again to all. You have been great!

Peachpitter