Deeavi

iTrader: (16)

I hope I am posting in the right section. I need some help with a project.

We have a 98 Camaro that we are changing from efi and going to a Demon carb and Edelbrock intake. It came with a MSD ignition/timing controler. I am bypassing the ignition and fuel injection harness, but want to leave the factory computer for other functions. I installed a "Race Pumps" fuel pressure regulator designed for use with an efi pump and carb. The (racetronics)pump on the car is fairly new

After setting everything up the fuel pump seems to quit pumping after intial startup. When I turn the key on. The fuel pump initializes and the pressure gauge reads correctly, then goes down quickly. Then the carb will run out of gas in few minutes and the engine shuts down. I can turn the switch off and back on the it does the same thing. There were no problem with fuel delivery before the swap.

Any ideas? Appreciate any help!

Magic Man

The pcm will only run the fuel pump run for like 6 sec and if it doesn't see startup it shuts the pump off. I don't know but what interface to it or signal you have taken off but it sounds like the problem is in that area.

98Camarod

iTrader: (43)

I'm pretty sure the fuel pump needs a rpm signal. Any particular reason you wanted to do the carb setup?

I see you're in summerville, thats not too far from me.

Deeavi

iTrader: (16)

The crank sensor and the cam sensor are pluggerd into the msd box now. I am going to try and jump the signal from the crank sensor back into the pcm harness as was suggested by someone else.

Thanks, guys

I am trying the carb for two reasons. I have spent a bunch of money on tuners and parts trying to get my car to idle correctly and consistently, but have not been able to get it done. So I am switching to a carb for that reason, and also it is different. As soon as I cranked it up with the carb it ran pefect until it ran out of gas.

As long as I don't have to pass emissions, I will be OK. I actually live near Bowman now, but my wife and I both still work in the Charleston area

98Camarod

iTrader: (43)

Tuning is expensive, thats why I got hp tuners and I'm doing it myself.

Off topic: what track do you run at? I went to the Dorchester track and couldn't hook for anything. There has to be another track around here

Deeavi

iTrader: (16)

I have HP Tuners also. My car has been a challenge. I have had three so so-called experts look at it, but they could not get it right. Oh it runs great other than idle. Right at 500 rwhp and 500 rwt.

I have not run my car at a track since I put the 427 in it. There are not many decent tracks around. Most are 1/8 mile. There is one here near me, but it is narrow and has a big cement divider in the middle? There is a nice track at Jackson, SC near Augusta. They run 1/8 and 1/4

Lonnies Performance

iTrader: (16)

To run your pump without the computer, run a wire from the ignition (switched 12v key on) to the fuel pump relay coil terminal. In this wire, insert a pressure switch that opens on a lack of oil pressure (normally open contact) connected to your oil pressure gallery in the engine (set at about 5#). This way your pump will not run without the car running & seconds after you crank the engine over, the pump will run.