So ive turned my attention to the engine in my trans am while i was waiting for my floor pans to arrive. I discovered that the enginr is a 727 block with 193 heads and apparently came out of 92 truck, LO5. It has the truck serpentine belt system on it which i guess im going to continue to use. It has edlebrock intake with holley carb. The car was originally a cc quadrajet and all the connectors are still there. They had the fan wired to a toggle instead of fan switch in head, i went to swap it out and noticed the plug is still in the head yet i cant get a 3\8 extension in it. Those were 3\8 drive correct. Also i bought a coolant temp sensor for the gauge but the threads are two small for the intake, any clue there? also the block is not set up for mechanical fuel pump so po installed a electric in line but it was wired straighg to battery. Im trying to wire a relay to oil pressure sensor behind dist. However i cant it to send signal with ignition on/ cranking to start the pump. Also when ign is on the op gauge reads above 60 same as unplugged. Also the return line is cut and crimped shut is this going to hurg anything. I think that is it for now unless i think of more

 

You got alot going on here. If i miss something its either I missed it or I have no clue.

1.Is the square 3/8 hole clean of dirt and or paint. May need to tap it in lightly to get past paint buildup

2. I'm guessing its a factory style sensor your putting in a aftermarket style intake. Some parts stores should find you a adapter like Napa where there employees actually know a thing or two.

3.You have to have a regulator or a inline pressure switch for electric fuel pump and carb combos or it'll flood. Carbs only need 5-8 psi as most electric pumps have over 100 psi. Obviously way to much

3 1/2. I wouldn't hook my fuel pump to my op gauge. I dont see how that would work.

4.Your oil pressure sensor is bad. Once I used carb cleaner with the straw to clean out the tiny hole in the sensor and it did start working again. Must have gotten contaminants in it some how. If that doesn't work get a quality ac delco one. Otherwise the cheap generic replacement will probably not last. Its just one of those parts that you have to get the quality made one.

5.Yes you need a return line. you'll burn up the pump with out it

 

Usually requires grinding a old drive down for a perfect fit
That plug is a bear to get out , often requires application of heat to the head as same time as wrenching on it to break it free

Prob need a 1/2" to 3/8" NPT reducer , avail any plumbing supply shop or better parts shop

http://www.summitracing.com/int/part...1204/overview/

Do you have full time 12v on the Org wire of the connector , will the pump run if you jumper the connector ?
If not you have no power to the switch.

 

So many things wrong there

Elec pumps come in different operating pressures and style; low pressure for carbs and high for EFI
Some elec carb pumps ( like a Holley Blue ) are designed to be dead headed to the carb so they don't need a return line or a reg
Only the top end HiPo pumps like a Aeromotive require a bypass reg and return line

Obviously don't know these cars.
Stock they have a oil pressure switch that runs the fuel pump as soon as you crank the engine over , a backup to the fuel pump relay
See diagram above

Because a carb holds fuel in the bowls and doesn't need the pump running to prime for startup like a EFI car , many wire the fuel pump through the pressure switch
so the pump runs as soon as the engine cranks over and turns off when the engine stops.
No need to remember to turn the pump switch off and on

 

[QUOTE=vetteoz;5696583]So many things wrong there

Elec pumps come in different operating pressures and style; low pressure for carbs and high for EFI
Some elec carb pumps ( like a Holley Blue ) are designed to be dead headed to the carb so they don't need a return line or a reg
Only the top end HiPo pumps like a Aeromotive require a bypass reg and return line

TRUE vetteoz. Should have asked what kind of pump he has before I made a suggestion.

What kind of pump do you have Midge54?

 

My camaro is a 87 that used to have a factory quadrajet like midge54's 87 trans am(last year for factory carbed f-body). When I bought my car it already had a mechanical fuel pump and factory quadrajet. I thought it came that way factory(please correct me if I'm wrong if mechanical fuel pump never came factory on the 87 carbed f-bodys). If so does my camaro have the connections and provisions for a electric fuel pump. Wouldn't the PO have to modify the sending unit in the tank to accept a mechanical fuel pump or like midge54's car to put on a in line electric pump outside the fuel tank.thanx

P.S. I have no OP sensor. I ONLY have a mechanical OP guage. I did all the rewiring when I took the 305 out and put in the 350. No wire to OP guage for fuel pump.

Obviously don't know these cars.

When a guy says"I don't see how that would work" that means "I don't see how that would work." I already admitted that I didn't know but thanks for telling me again.

 

I can't say for certain, as I haven't dealt with an 87, but yours may have come with the in-tank electric helper PLUS the mechanical up front.

 

I've torn down about everything on my car and put it back together minus fuel tank and front suspension. Would be nice to know exactly how it works seeing as my tank never needed work or modification for my setup.

 

What kind of pump do you have Midge54?[/QUOTE]

It had a purolater pump on it but it quit working so I need to get a new one

 

Krisner89 your camaro should be like my trans am was meaning that you had a mechanical pump on the block and an in tank pump to prevent vapor lock

 

IIRC
carb cars also had a return line from the mech pump for the same reason;
to allow the elec pump to pump fresh cold gas up to the mech pump when the key 1st turned on

 

http://92b4crs.tripod.com/86wiring/dia-pics/23-4.jpg