Werewolf SS

iTrader: (3)

Hey everyone I have a baffiling situation that you all might have some answers on.

My camaro was a tbi swapped to carb. Fuel Pressure Regulator mallory set to 5 psi.

The engine ran fine prior with the fuel line working with out issues.
All of a sudden now the fuel pump won't turn on during the 3 sec key turn or when the oil psi is above 5.
The weird thing is when the 3 sec fuel pump key turn happens I don't hear the fuel pump whine or make noise but I do hear a click from the relays near the firewall and then after 3 seconds another click.

Which realy should I look at our is there another answer?
I checked the fuel pump fuse at the battery and it's fine.

Any help would be appreciated!

camaronewbie

You will NOT get the 3 second prime of the fuel pump without the ECM in place - the ECM makes this happen. The only time your fuel pumpo will turn on at all now is when your oil pressure sending unit gets an oil pressure signal and turns on the pump. All other fuel pump issues are handled by the ECM (which you don't have anymore).

I took the fuel pump wires from my OPSU and rigged them into the original fuel pump relay - I did this for 2 reasons:
1) NOW my fuel pump runs anytime the key is on
2) It tales the OPSU out of the equation - a bad OPSU can make the fuel pump not run, and it can also make the fuel pump run always regardless of the key - I've had both cases happen in the past and thus decided to take the OPSU out of the fuel pump picture for those reasons.

Werewolf SS

iTrader: (3)

Thanks for the response let me quickly clarify.
My Ecm is still in the car (I took the Check ENG light out) just to make sure I would still get the 3 second prime to fill the fuel bowl of the carb.

I can hear a click from the front relay's on the driver side firewall and 3 seconds later another click during the prime stage. It worked prior as I had the engine running with the carb for awhile before it suddenlt stopped running the fuel pump during the prime stage and even when the cranking of the engine gets the oil psi over 5.

I'm hoping it's just the relay but wanted some confermation prior to getting a new relay.
Thanks for the help though.

camaronewbie

Hmmm. Might be the relay then. What about the fuse at the battery? Its in a weather pack tucked in the fender just behind the battery. But, if it's blown, I don't think the fuel pump will run at all, regardless.

No real need to 'fill the fuel bowl on the carb' by using the ECM and relay function. All carbs hold enough fuel in the bowls to start the car, and usually drive a block or two. That's why there are bowls there, to hold fuel until the pump starts pumping fuel.

Might want to consider getting rid of that system, rigging the relay directly to the pump using the wires from the OPSU, and running a hot-in-run wire to the relay like I did. One of these days that OPSU is gonna mess with you like it did me, and leave you stranded until you figure it out. I was at the GM Nats in Carlisle PA (400 miles from home) when it happened to me - luckily I had the tools and wiring necessary with me to bypass all that and get her running again to get home! Now with my setup, only 2 things can go wrong, fuel pump and relay - and the relay is available at any parts store.

lilhack69

iTrader: (7)

did you set the fuel pressure regulator up one line in two lines out. two lines out meaning one fuel line to carb and one returning to fuel tank. if you didn't most likely you fried the pump. the returning fuel cools the fuel pump.

vetteoz

iTrader: (13)

Fuel on the supply side cools the pump; return line doesn't run through pump