I decided to switch to carb, I went with the stock pump and a mallory 3 port reg. I got no response from the pump after 2 or 3 seconds of key on. So, in order to move the car I threw in a cheap inline carb pump, while leaving the stock pump energized.

The car ran surprisingly good, so I took it for a spin. About 15 minutes later the engine slowly started to shut off. I'm assuming that the stock pump is screwing with the carb pump (pickup) causing problems?

My question is...do I need to drop the tank and throw in a good carb pump...doing away with the regulator, or does my problem lie elsewhere?

 

You weren't getting anything from the stock pump, because the ECM isn't seeing reference pulses from the distributor to turn the pump on anymore. The oil pressure switch should still have powered the pump after the engine started though.

 

also if you are going to stay carbed the drop the tank and swap to standard carb pump, easier to change than having to drop tank again.

 

Yea I know...I'll be dropping the tank soon and doing this the right way. I honestly think this regulator is a pain. Any suggestion on pumps? I've heard the holley pumps don't last long.

I am confused by the oil pressure sender and the oil pressure switch. Are they the same thing? I have a cylinder looking device (with one spade crimped wire attached to it) just to the rear of the manifold. Don't know if it is a sender, a switch, or both.

 

that sounds like a simple sender unit, basically the same but one has a switch internally for the pump if oil pressure gets tooo low. also the switch unit has 2 terminals. folks here in the desert are doin great with the edelbrock pumps.

 

Oh I see, so if I swap my sender for a switch/sender combo I should be alright?

I was digging in the area around my sender. I found a plug that was rather orange/red in color...2 wires. Would this be the plug that I am looking for?

Pics...(sorry night...had flashlight in one hand)

 

yeah it looks like someone has installed an older sender unit to make your gauge work and the orange connector appears to be the corect one. the wire colors should be orange/black, tan, tan/white.
the tan is the original gauge wire the other 2 go to the fuelpump relay.

 

also if you find those wires put a jumper between the o/b and the t/w temporarily to see if it solves your problem if it does the you can just splice a toggle switch between them under your dash and it gives you instant security system.

 

Yup...that was it. I only only saw two contacts on the plug...but it I saw where the tan wire was pulled. I guess it just snaps into a metal clip internally.

So all that jargon leads me to this. If my in tank pump was working properly, I would be able to fire and run for awhile, right? However, the only way my car ran (drivable) was by installing a 7 psi boost pump in the engine bay. After the oil pressure dropped, the ECM cut power to the fuel pump.

This tells me that while the pump was energized it was open, but not pumping gas correctly. But when the pump was deenergized it cut all access entirely...including supply available to the booster pump.

Does this make sense?
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I hear ya...but that doesn't solve the problem of low oil pressure, correct?

 

may have just lost the original bypass that was put in before you bought the car. the oil pressure could be watched by the gauge then you would know whether you have probs or not. the external switch just gives you a way to save some money if your oil gauge works