trochoid

iTrader: (6)

Unless you have a stock 1st gen fuel pump installed, 95% chance you will need an fpr. Post a pic ot the specs on your fuel pump. Switched ignition source is just that. It has power when the key is in the on position. You can either test wires in the FC harness or wire a fresh one in.

Valdez

iTrader: (1)

Hi Trochoid,

So what you are saying is that the fpr uses a wire that only is hot when the key is in the on position, and from that wire, I splice it and run it to the solenoid connector as well? Or I could also find a wire that is already doing that and run it to the solenoid? I am quite certain that I have a first gen fuel pump. I doubt I can get a good picture of it. It is tucked up above the gas tank and under the body of the car. I can barely see it, but I can see that the hot wire that used to go to the second gen pump was cut and is now running to the other pump. There is also a ground wire coming from the first gen pump. The second gen pump is now simply acting as a hose for the first gen pump to draw fuel through.
I have taken the air horn off to oil the needles and put the retaining clips on. I noticed that there was only a little bit of gas in the front bowl and nearly none in the bowl near the firewall. Still having difficulty with the retaining clips. If they are installed in a certain position they work, but they seem to eventually swivel around and get caught under the float arms so they barely move. While I was working the needles up and down with the floats attached I watched it happen.

I have attached a few pictures:
One is of the the connector that I found. No idea what it is for yet. Might not be needed at all or have nothing to do with the solenoid.
The other two pictures are of the clips attached to the floats. The one with the arrows drawn in shows the retaining clip (yellow arrow) stuck under the float arm (red arrows). The other pic shows the clip out of the way and doing its job (until it swivels and gets in the way too).

trochoid

iTrader: (6)

Top part of the clip goes across the tab and should not be rotating, if it is, bend down the end of the top clip so it stays in place. I need to pull the carb apart I'm working, again, lol. I can post a pic later of how the should set. The fpr is strictly mechanical, no electricity needed.

To power the solenoid, find a wire that is dead with the key off, hot with the key on. To simplify things for the moment, run a wire off of the - side of the trailing coil to power the solenoid. That should open the solenoid for now and it is switched power.

Valdez

iTrader: (1)

With the retaining clips in and the air horn inverted, the distance between the float and the gasket has increased by 4mm.
With the air horn in the normal position, the float distance remains the same, but some times when pushing up on the float it can get locked in place by those clips binding on the float arms and gravity won't pull it down again.

Valdez

iTrader: (1)

A picture sounds good Trochoid, These clips are frustrating.
I'll poke around for a wire to use with the solenoid, once I get these clips working and carb back together.

trochoid

iTrader: (6)

Went and looked at a carb I have apart, your clip is in right. You might try taking the plunger and spring out of the needle, cleaning and oiling them. Might be part of the binding.

Valdez

iTrader: (1)

Nope it's the clips. They are binding up the movement of the floats and pins. Some thing just doesn't seem right. There is too much play and they don't have a smooth action. If the floats are super floaty then maybe there won't be much concern. I'll try them anyways and see what happens.

Valdez

iTrader: (1)

Here is another update.
Not a lot of progress. I put the oiled needles and clips in a few days ago. It flooded on me the first try and since then I only got it going again yesterday. when it did go, it still only ran for a minute then crapped out again.

Valdez

iTrader: (1)

Hi guys,

I tried to hook up the soleniod you mentioned. I found an unused connector that had power only when the key is in the on position. When I tried it, it only seemed to make things worse. When cranking, fuel was pooling up big time in the chamber marked with the arrow. Once I unhooked it, there was no more pooling. When cranking over, the carb is also pissing gas into the chambers. Shouldn't it be more of a spray? Could the dying out after a minute be caused by fuel overdose rather than lack of fuel? I think I may have to break down and get a regulator as nothing else seems to be helping.

Valdez

iTrader: (1)

It's been a few weeks since my last post. I got a little busy doing other things. today I decided to do a volume test to see how much gas is being pumped out. The instructions say to leave the key in the on position (don't crank). I did this and no gas came out of the line. If I crank it, the fuel comes out thou. This doesn't sound right. What could it mean? It will start now, but will only run for about a minute before it dies out.

Valdez

iTrader: (1)

bump

Valdez

iTrader: (1)

For some reason I've stopped getting fuel. Since I got the car, the gas gauge has been on empty, so I assume it could be out of fuel. I fill my jerry cans and put $27 or 30 Liters in the car. Now that I should have enough gas, I decided to test the pump. I disconnected the hose off the end of the pump and turned it over for half a minute. Not a drop came out. I could hear the pump and feel it vibrate, but no gas. Could this be just a bad pump or could it be a problem inside the tank?

Remember I have a 2nd gen with a 12A setup. The 1st gen fuel pump draws thru the unpowered 2nd gen pump in the tank (like a straw).

Also, why would my gas gauge still be on empty after adding that much gas? Seems like the guage isn't working. Hard to say how much gas was already in it.

trochoid

iTrader: (6)

You could remove the FI pump from inside the tank and extend the pickup tube. A better option, imho, would be to use the 2nd gen pump, then add a Mallory 4309 fpr to bring the fuel pressure down. If the intake pump is bad, you can pick a Walbro 255 lph for around 100 bucks on eBay.

That way you could plumb the fuel system back to stock and perhaps eliminate some problems. While you have the fuel pump/pickup assembly out, you can inspect the tank for contamination, along with the pickup screen.

13BT_RX3

You may want to install a fuel pressure gauge. This will tell you when you have fuel pressure and if it is too high.

If you remove the line that feeds the cab and switch the pump on does anything come out?
If not try connecting power to the 2nd gen pump and see if it can move the fuel. How does your fuel filter look? Have you changed it lately? You may have junk in the 2nd gen pump inlet from running the tank down.

I agree with trochoid that it would be OK to run the 2nd gen pump on it's own if you get a fuel pressure regulator installed (with gauge).

When you get fuel flowing again and have a pressure gauge you should turn the pump on, but not the car and adjust the floats so the fuel is at the marks on the windows. If you have fuel coming out the carb with the engine stopped and the pump on there is a seat problem. It could be a sticky seat and float assy, debris under the seat or too much fuel pressure. You need to get the carb to hold a constant fuel level with the pump on and the engine off.



When you get the flooding problem and you remove the needles and seats do you find any dirt?

coldy13

Using the FC pump with a pressure reg and gauge would be better than the 12a pump. Take off the top of the carb and leave the fuel line on, turn it upside down and turn on the fuel pump, the floats should seal and no fuel should come out. Make sure the needle is moving freely and the floats are at the right level.

Valdez

iTrader: (1)

Thanks for the input everybody. I'd rather not pull the 2nd gen pump out unless it is screwed, as I may want to put another 13B in one day. I should hook it up again like suggested and see if it gives fuel. If it does then I guess it is safe to assume it is the 1st gen pump having problems. The pump only is on when the engine is turning over, with the car not running and the key in the on position, the pump stays off.

I can't test much at the carb for now as fuel isn't even making it out the pump. When I did take the carb apart a couple weeks ago to oil the float needles and install the clips, there was no dirt or grime in the needles and float assembly. They moved in and out with ease. I am concerned with the clips getting in the way of the float tabs thou.

Anybody know how to trouble shoot a non-working gas guage?

trochoid

iTrader: (6)

On the 2nd gen fuel system, the pump does not start until the engine is cranking. Once the the engine has fired up and the key returns to the run position, the ecu recieves a signal from the afm that the flapper is open. If it does not recieve that signal, the pump shuts off.

A work around for this is there is a jumper to test the fuel pump with the key in the on position. Download the 87 FSM, you will find the jumper connector in Sec 4A, p. 66.

For the gas gauge, there is a test in the manual for the sending unit. If all of the wires going to the tank were disconnected to disable the oem pump, the fuel sender is unplugged too.

Valdez

iTrader: (1)

Hi Guys,

Thanks for all the advice so far. Here is an update.

The car is now getting fuel. I believe I had a blockage in the fuel pump. It is now running smoothly. My problem is now the flooding of the secondairies. I am unsure of the air vent solenoid as well (see pervious reply with pic).

This thread is getting kind of long, so I will start a new one from the point I am at now.

Valdez

iTrader: (1)

If anybody's still following:
https://www.rx7club.com/1st-generation-specific-1979-1985-18/secodaries-flooding-593963/