#1
IP: 69.117.234.216
|
|||
|
|||
Coil & fuel pump bench testing questions
Just bought a ’67.
My first hope is to get it running here without the alternator tied in, and then figure out what I have in the way of alternators. I need a bit of advice on running leads to the coil and the use of an electric fuel pump (my first). Gentlemen , do I understand right that without the alternator I can run a positive lead directly from the battery positive to the coil positive ? (as long as it’s not on when the engine is off) I‘ve successfully jumped the starter by rigging: 1) a ground from the engine block back to my battery negative. 2) a cable from battery positive to the large connection on the starter solenoid I have a switch in between the “S” on the solenoid and the large positive connection ; of course when I throw the switch she turns over. My next move, I think, is to: 1) rig a switch that will run from the battery positive to the coil positive 2) give the fuel pump power Here I’m on shaky ground. Facet Pumps websIte has NO specs on this pump. There are two reds exiting the oil pressure sensor, and a black that leads to the pump. It looks very obvious (last words); just run 12V positive to the red lead with the fuse. Perhaps using the same switch that will give 12V to the coil. This assumes the pump always has 12V. Yes ? |
#2
IP: 24.152.131.153
|
||||
|
||||
Correct on all counts.
Let's talk about the OPSS. You report and your picture shows two red wires and one black wire connected to the OPSS. Can you confirm the two red wires connect to the same terminal? What follows assumes that's the case. The two terminals on the OPSS are merely a single pole switch. One terminal goes to a 12 VDC [+] source, most commonly the ignition wire, and the other goes to the fuel pump [+] (the black wire). The pump picks up it's 12 VDC [-] from the mounting bracket. Note that the terminals on the OPSS are not polarized, it can be connected either way. Judging by the picture and again assuming you have a 2 terminal OPSS with both reds on the same terminal, connect one red to the coil [+] post and the other to your makeshift ignition switch. The other side of the ignition switch goes to your 12 VDC [+] hot source.
__________________
Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#3
IP: 199.168.148.136
|
|||
|
|||
The "stock" set up is to run a switched hot lead to coil+ so it is energized when the key or switch is on then a wire from coil+ to one side of of the OPSS. The other terminal of the OPSS is connected to the fuel pump.
One of the red leads was probably connected to coil+ and the other lead went somewhere to energize something else when the key or switch was on. I would ditch them both and run a single wire from coil+ to the OPSS. Or you can connect one of them to coil+ and cut the other one off. If you want to bench test the engine you can temporally connect the fuel pump directly to coil+ and bypass the OPSS. TRUE GRIT |
#4
IP: 69.117.234.216
|
|||
|
|||
The two reds have independent connections to the switch
Thanks guys.
As you can see in this new shot, the two reds have independent connections to the switch (this OPSS is totally new to me also; nothing like it in my 10 years with the A4 in my own boat) One red shares a connection with the black to the pump, and so I’d think this is the one to give power to. (Or not ! If there is switching going on then it must be between the two contacts on the switch face) What’s confusing me is that the other red has the fuse. Yup. Confused. |
#5
IP: 24.152.131.153
|
||||
|
||||
The second red connected to the same terminal as the black went to a certain type of starter solenoid to operate the pump during starting regardless of oil pressure. Some like it, some don't. I think it complicates issues and is unnecessary. Use a single wire to each terminal and connect it as John suggested and you'll be good.
Thanks for the detailed picture.
__________________
Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#6
IP: 199.168.148.136
|
|||
|
|||
Hook one end of the wire that has the fuse in it to coil+ (or the switch) and the other end to one terminal of the OPSS.
Cut the red wire away that is co joined to the fuel pump lead and hook the fuel pump to the other terminal of the OPSS. Explanation: The co joined red wire is a OPSS bypass wire. Some A4s came this way. Mine did. The other end of the co joined wire goes around to the starter so as the engine is being cranked the OPSS is bypassed and the fuel pump will operate before the engine starts and the oil pressure comes up. You can run the co joined wire to the starter if you want to preserve this feature. As Neil noted some like this feature but it is uneccssary. TRUE GRIT |
#7
IP: 24.152.131.153
|
||||
|
||||
A word of caution regarding the bypass wire: not all starter solenoids have the 'R' terminal (I think it's 'R') where this third wire goes. Especially for bench testing I'd forget about it. This is the time to keep things simple.
Be sure you do not connect it to the 'S' solenoid terminal or your starter will engage when the oil pressure comes up.
__________________
Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#8
IP: 199.168.148.136
|
|||
|
|||
That friggin wire had me guessing for ~ a year.
I was getting shut downs and couldn't figure out why. When I did my rewiring project I removed the bypass wire to the starter and noticed that where it turned the corner by the distributor the insulation was worn away. With that wire being shorted to ground coil+ was being grounded when the engine was running and the OPSS was closed! Why it didn't start a fire I don't know. The wire did look a little fried. Fuses are a good idea. TRUE GRIT |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Possible bad Facet fuel pump? | TomG | Fuel System | 8 | 05-17-2011 05:23 PM |
How much fuel should a fuel pump pump if a fuel pump does pump fuel? | Baltimore Sailor | Fuel System | 6 | 12-02-2009 09:22 PM |
Fuel Pump ID? '79 Catalina 30 | NorfolkRagbagger | Fuel System | 5 | 08-24-2009 03:41 PM |
Facet fuel pump notes | rigspelt | Fuel System | 3 | 01-03-2009 01:31 PM |