My first garage thread / fuel pump, Relay board modification. Options

[914boy]

The car was carbs and the fuel pump was on constant when the key is on.
I am trying to put it back to factory settings.

As far as I understand in djets, when the key is turned on, there is a pulse to turn the pump on for a quick second then once the car starts the ecu keeps the power on to keep the fuel pump running.

I am not getting that pulse. The relay clicks and I even switched the relay.
I noticed that the PO modified the connectors on the relay board for the carbs.
(See pics) please help me she's some lights

The car is a 1.7 djet year 1970

Thanks

[914boy]

More

[worn]

Well it looks like the relay board is OK, which is sort of too bad because if that was the problem you could just swap. The owner would have wanted fuel pump when he turned the key and thereafter, and probably didn't want an injector brain. It looks like the biggest changes were to the engine harness. You can trace things though the schematics - not that bad because there are lots of resources or you can find a new harness. Look at Jeff Bowlsby's sites whatever you do.
(IMG:style_emoticons/default/welcome.png)

[914boy]

He had the gree/yellow wire shown on the second pic, attached to the fuel pump wire (black with red stripe) , where was the green/ yellow going originally?

[timothy_nd28]

[timothy_nd28]

Looks like the green/yellow wire is part of the optional sportomatic transmission. This wire is unused, and it is possible the PO decided to install a switch somewhere near the dash to toggle on/off the fuel pump? Do you have a picture of the fuel pump wire splicing into this green/yellow wire?

[Dave_Darling]

Remember that the wiring can differ slightly from year to year. For instance, my 74 has a green wire looping from one pin of the 12-pin connector to another.

Here's the 71 relay board, the 71 should be identical:

(IMG:http://www.914world.com/bbs2/uploads_offsite/www.pelicanparts.com-121-1370298770.1.jpg)


Compare the colors in the connections to what you have.

It looks like you may be missing a couple of relays on the board? You need the middle two to run the pump; one of them powers the FI and the other powers the pump. The pump will not run unless the FI tells it to, BTW.

--DD

[914itis]

Remember that the wiring can differ slightly from year to year. For instance, my 74 has a green wire looping from one pin of the 12-pin connector to another.

Here's the 71 relay board, the 71 should be identical:

(IMG:http://www.914world.com/bbs2/uploads_offsite/www.pelicanparts.com-121-1370298770.1.jpg)


Compare the colors in the connections to what you have.

It looks like you may be missing a couple of relays on the board? You need the middle two to run the pump; one of them powers the FI and the other powers the pump. The pump will not run unless the FI tells it to, BTW.

--DD

Dave

All the relays are there except for the rear window defog.
In my 74, When I turn the key on, it primes the pump, is it the same case for the earlier cars?

[Dave_Darling]

All D-jet cars should prime the pump for about 1.5 seconds when the key goes from "off" to "on".

--DD

[timothy_nd28]

Interesting, pin 11 (brown white wire) from the 14 pin connector is the same tract as this green/yellow wire pin 10 of the 12 pin connector. This is the wire you had in question. The brown white wire has its insulation stripped for whatever reason. Both wires serve no function, if I'm reading the diagram right and if your car is indeed a 1970.
This gives me a great idea for my car. I need to feed a wire for my trunk solenoid to the dash board. Since pin 11 and pin 10 are not being used, I could steal that wire for a clean trunk switch installation.

Towards your problem, you say you hear the relay click, or is it clicking from you testing it? I'm assuming you removed the carb and already installed the brain and the other Djet FI stuff?

[euro911]

A jumper to ground on the relay board is typically needed to keep the pump running when installing carbs.

Post a pic of your whole relay board. We're looking for a jumper to ground from one of the terminals (marked I, II, III and IV on the image Tim posted, and marked 1, 2, 3 and 4 on the image Dave posted) located on the rear driver side of the board.

Don't quote me, but a jumper from terminal III (3) to ground appears to complete the circuit for the coil in the relay (75) (which would close the contacts and keep the pump running when the ignition key is on).


Again, post a pic so we can see what's going on there (IMG:style_emoticons/default/popcorn[1].gif)

[914itis]

Yes the III was grounded, in addition pin # 10 on the 12 pin connector (yellow-green) is jumped to the fuel pump wire ( pin 13 of 14 pin connector b/r)

We understand the reason for the ground as Mark pointed out on carbs for constant on, but don't understand the reason for the jumped wire.

We will put the full system together and troubleshoot from there.

[914itis]

Update:
we put the fuel injection system together, including ecu, injectors, harness, throttle body, and mps. The only thing that's not connected is the coil. I turn on the key, the relay clicks but the pump did not make that first turn.

Can it be a bad relay board? or the 1.7 djet does not turn the pump momentarily when the key is on (IMG:style_emoticons/default/confused24.gif)


We have not attempted to crank yet.

[914boy]

We solved the issue with the fuel pump. The pump primes fine. One of the relays was bad.

Phase 2 :

We try to start the car, it cranks but does not start.

Timing and TDC are checked and spot on,

the coil will not spark.

Just to confirm. The thick black/ purple is on the positive (+) side of the coil and the small black and condenser on the negative (-)

With the ignition on, I get 12 volts at the + / black/ purple wire
with the ignition on, I have ground on the negative side of the coil,
when I crank, the negative side of the coil switches from ground to 12 volts positive

I replaced points and condenser, Same issue.