'73 CIS FP Relay ok for '77 CIS??

[djudge1845]

On the '73 FP relay wiring diagram, power from the fuel pump comes into 30 and if 85 (VR D- ground) and 86 (VR D+/61 blue wire) are energized, the circuit to 87 (wiring to WUR) should be completed.

I have a '77 2.7 CIS w/ the WUR, Air valve and thermo valve wired using the above mentioned configuration. When i look at the '77 wiring diagram, it appears these three devices are wired directly to 30 on the FP relay with no need to be energized by D+/61 which appears to be the alternator warning lamp. Since the WUR, etc should be getting power whenever the fuel pump is on, running it through a relay involving the alternator warning lamp is not logical as it would either energize when the ignition is on (alternator not yet charging) or energize when the engine is already running and alternator charging. That would make starting difficult.

At present, I do not have power on pin 10 when the ignition is turned on but I know I have power at FP relay 30.

Does anyone know if the '73 was wired that way and is not compatable directly w/ '77 2.7. If so, was my thinking correct that I should just wire pin 10 directly to FP relay 30.

Thanks for any information and suggestions.

[Gogar]

I did not know there was such a thing as a '73 FP relay.

[E Sully]

The '73.5 cis is different than the later cis, it does not use a thermotime switch or fuel pump relay.

[djudge1845]

Sorry I should have posted the link to our host site. I probably shouldn't refer to it as a FP relay as it appears to get power to 30 from the FP relay and appears to power the wur when energized.

http://www.pelicanparts.com/911/911_Parts/Electrical/911_electrical_1973_CIS_add.jpg

Does that help? Thanks for the help

[djudge1845]

Thanks Ed. Ok this isn't a FP relay, what do we call it - a WUR relay? I know I am attempting to power three devices on the '77, but still should work as they are all wired together and if I can get power to 87 in the relay shown above they will all be powered.

Thanks Ed - beat me to posting the relay diagram.

From the diagram above, can anyone tell me how 85 and 86 can be energized ALL the time once the ignition is turned on. 86 is the blue wire from the alternator and goes to the alterantor warning lamp. Seems to me 85 and 86 can energize 30 and 87 either when the lamp is on (ignition on alternator not charging) or when the lamp goes out because engine is running and alternator is charging. Is it possible that in the '73.5 that what was intended or do I just not understand how the relay is working?

[ossiblue]

Maybe I'm missing something but I don't quite understand the problem.

I have a 73.5 with a 76S engine--nearly identical to your set up. The fuel pump has no relay, as you know, and the relay shown in the diagram is for the WUR and shows it's powered when the engine is running (alternator is charging). Why do you need to power the WUR, AAR, and AAV with the ignition on instead of the engine running? My devices (WUR, AAR, AAV) are set up to get power from terminal 87 just as shown in the diagram and I have no problems with starting. Your car should start without difficulty with no power to the devices mentioned--just the fuel pump--as all the devices powered by terminal 87 are supposed to change their operating functions through "warm up". In a cold start, they are all in their correct operating mode with no power. With the engine running, they all change specs through wired power and engine heat conduction so there is no need to power them before the engine is actually running.

[RWebb]

my 73.5 had no FP relay either - quite an oversight by P AG

it would be very smart to add one, along with some of the other components of the more advanced CIS ... assuming you don't remove all the CIS and put on some decent fuel system, of course

[djudge1845]

Thanks L.J.
Great point - they WUR, AAR & AAV are in the correct mode for starting and only need correction as they engine warms. Power would only be needed once the engine is warming and by that point there s/b suficient charging from the alternator. Of course if the alternator or regulator are not operational we'll also have poor engine performance.

I was foolishly looking for power at the WUR with the ignition on. I will reinstall the alternator (have it wired but not installed) and anticipate there won't be an issue.

Appreciate everyone's input - stops me from banging my head against a wall.

[boyt911sc]

Originally Posted by djudge1845

Thanks Ed. Ok this isn't a FP relay, what do we call it - a WUR relay? I know I am attempting to power three devices on the '77, but still should work as they are all wired together and if I can get power to 87 in the relay shown above they will all be powered.

Thanks Ed - beat me to posting the relay diagram.

From the diagram above, can anyone tell me how 85 and 86 can be energized ALL the time once the ignition is turned on. 86 is the blue wire from the alternator and goes to the alterantor warning lamp. Seems to me 85 and 86 can energize 30 and 87 either when the lamp is on (ignition on alternator not charging) or when the lamp goes out because engine is running and alternator is charging. Is it possible that in the '73.5 that what was intended or do I just not understand how the relay is working?

djudge,

I re-read your initial post several times and got the impression that your are referring to the WUR's relay ('73) as FP relay found in the later CIS engines. The #30 terminal in the electrical diagram submitted by Ed Sullivan is not the same as the #30 terminal (FP relay) that supplies power to FP, WUR, AAR, & TV. The '73-'74-'75 (911) are wired to make the FP run when the ignition switch is turned @ ON position. But not the '76-'83 CIS engines (with FP relay).

While it could be done to supply power to the FP, WUR, AAR, & TV utilizing the '73 set-up by tapping @ #87 (WUR relay), I would not recommend it. Instead install a 5-point relay similar to that of the later CIS engines so that the safety feature offered by the AFS is fully utilized.

When the ignition switch is turned @ ON position, there will be no power at #10 (14-pin connector) or at #30 (FPR) which you don't have but you have the #30 (WUR relay) which would have power. These #30 terminals you are talking about are two (2) totally differeng things. Keep us posted.

Tony