Fuel Pump????

[todd914]

Maybe I'm just no understanding the way it works, but I have yet to figure out what tells the fuel pump to kick on. I have isolated the + for it and I have a good ground, but when I test it with a test light, no power. What is a good way to manually turn the fuel pump on through the relay? I have just reinstalled FI on my 1.7 and kind of lost. The relay holes are getting power at the board. Any help here guys?

[pbanders]

Check out my fuel pump operation flow charts at:

Fuel Pump Flowcharts

[Dave at Pelican Parts]

Bill Williams wrote up a (lengthy) description of how the fuel pump circuits work as well. It lives on Tim's 914 Fan Page. http://www.914fan.net/fuelpump.html

You can rig up a jumper on the fuel pump relay--from pin #30 to pin #87--to force the fuel pump to run all the time. And I do mean all the time, even when the engine has been shut off. That technique got me home from an autoX once... It can also let you verify the wiring from the relay board to the pump, and the pump itself.

--DD

[JRust]

Okay where is the fuel pump & filter. I see the picture in haynes manual but not sure of location

[Dave at Pelican Parts]

Lower right front corner of the engine bay. Visible from underneath, if you can manage to look around the heater hose. That's on the 70-74 cars.

The 75-76 cars have the pump up under the gas tank; there's a special access panel at the back of the front trunk compartment.

A popular place to move the pump in early cars is in the steering rack compartment. If you don't find it in the stock location, look there. Remove the gravel pan and look around.

--DD

[vwzorm58]

On 70-74 1.7 and 2.0 with d-jet FI (not sure of the others), the fuel pump should have power for about 2 seconds every time you turn the ignition from "off" to "on". This is to prime the pump and (hopefully) build pressure in your fuel loop. Then the pump will continue to get power as long as you're cranking the engine. If the engine starts then the pump continues to run, but if it doesn't start and you stop cranking, no more power to the pump. Hope this helps.

BTW, I see you're in San Antonio. I was there from 1989 - 2000 (and had my 914 on the road from 1995). There are several guys in PCA that are in to 914's. If you're not in PCA, you might want to consider it. When I was there, we had like 10 autocrosses/yr!

[JRust]

On another post the heater blower is mentioned. In checking these out does the heater blower turn on with the key? Or does it only come on when engine is running? Mine does'nt come on with the key. Of course it won't start either. So I'm going to check my fuel filter, pump & all wires connected. How do I check for the heater blower. Thanks for the info guy''s I think I'll have it licked by tomorrow

[Dave at Pelican Parts]

With the key, but only when the "DEFROST" handle is up all the way.

--DD

[JRust]

Hotwired the fuel pump & it worked fine. Sounds like I got a bad relay? Heater blower also not working. I'll be pulling off my fuse panel & making sure nothing is corroded. I'll be checking the relay too & if that don't fix it I'll be back

[Dave at Pelican Parts]

Could be the relay, could be something else. Go through the flowcharts and/or article--those will tell you where the problem is.

--DD

[JRust]

Hey your troubleshooting guide for the d-jet was great. After about a half hour of tests I found I had a bad relay. Bought a used one from Parts Obselete close by. Would like a new one but didn't have the $300 to pop for it. The used one ran me $50 bucks & he gave me 2 just in case. They are primarily a 356 place.
Until last summer that is. They bought a Porsche junk yard in Cali.
They carted up 17 semi-trucks full of parts. Including tons of 914 parts. [COLOR=red][URL]http://WWW.356SHOP.COM
Talk to Gary Emory there. Thanks for all the fuel tips guys!

[pbanders]

Jamie, $300 for a round relay? Can you say highway robbery ? Even $50 for a few used ones is pretty steep. Pelican sells them new for $18.10, and I can usually get them from the local junkyards for almost nothing.

Paying too much for 914 parts is something we all do. I'm currently soaked for $500 on some items that I didn't take the time to verify the conditon of before I sent the check

[JRust]

Sorry I meant to say my relay board was shot. The relay itself was ok in the new board. Minor difference in price huh? I would have prefered it to be just the relay. Thanks again for your guide Brad