i swaped my car from TPI to carb and when i went to turn the motor over for the timming i noticed the fuel pump didt kick on at all none of the wires that go to the distributer are connected so i dont know if that would matter and also the oil sending unit on the back of the motor isnt connected i ended up cutting the wire i also heard that could be why it doesnt prime when the key is turned. really i just need help with getting my fuel pump to kick on and stay on.

 

ive also head about running a 12v wire from the FP relay to something that runs 12v like the windshield wiper motor kinda leaning towards that route if anyone has done that can they explain exaclty what i need to do i have no experince with wiring so ill need a step by step

 

I did it. I linked to the thread I posted to discuss it, a solution is also discussed.

https://www.thirdgen.org/forums/elec...lay-wired.html

 

The pump is initially primed when you turn the key to "ignition on" by the computer. As long as you left the computer in tact after doing the swap, you should hear your pump initially prime. Even with the computer unplugged, however, your fuel pump relay should still be able to power the pump but it won't prime if the computer itself isn't plugged in. The oil pressure sending unit is used kind of as a fail safe. In other words, if your fuel pump relay fails to power the pump, then the oil pressure sending unit will kick on the pump once two lbs of oil pressure are detected.

If your computer is not still hooked up, you can either hook it up and listen for the pump to prime or you can crank the motor over and see if fuel is coming through the lines. If no fuel is coming through after you try to turn your motor over, check the relay which is located on the drivers side of your firewall. You will see two similar looking relays right next to each other. The one you are looking for is the one on the right.

 

Also, before you try to time the car your going to want to connect your distributor wires. You aren't going to have much luck timing it without it initially running first!

 

we got it to fire once and tried adjusting the timming with no luck and i ran power to the fuel pump wire but the whole time its on it sounds like its priming the whole time not like when i still had the 305 and it would prime for a few sec then stop it does it the whole time i have power to it now

 

i put power to the relay on the left towards the motor to the tan and white wire

 

So the pump is priming? When you say it sounds like its priming the whole time do you mean that you can hear the fuel pump constantly running? Or do you mean that it sounds like the fuel pump turns on then shuts off and then re primes etc?

 

To clarify, if you can, turn the car over again and when you shut it off, listen to see if the fuel pump keeps running. If you can hear your pump constantly running and it continues to stay on even when the motor isn't running, your best bet is that there is a problem with your oil pressure sending unit mishap.

 

The computer is responsible for the pump priming in seconds. If somehow you have eliminated the computer wires to the ECM, it will lose that ability. As far as running the hot wire from the fuel pump relay to the wiper motor. I wouldn't recommend it.. The amperage that the wiper uses is alot more and could cause a wire melt down with the extra draw from a fuel pump. If you wanted to run it anywhere, I would find another circuit that you can use with a 20amp fuse that is ignition switched on and off.

 

i no longer have the oil sending unit and we havent got the car to run yet it wont fire up so i dont know if the pump withh turn off but the whole time i have the pump on it sounds like then it primes it doesnt shut off it just stays that way the whole time

 

If you can hear it priming then the motor should still be able to start, if only briefly. Pull the fuel line off of the carb and then turn the key. If fuel comes out of the line then your pump is properly priming and fuel isn't your issue with the motor not firing. If you do have fuel, play with your distributor while someone else attempts to start the car. Your timing might just be off. If no fuel comes rushing out of the fuel line, post back and we'll help you from there.

 

I think i need a diffrent distributer and that why it wont start and it primes but it does it the whole time makes that noise because i have it on a toggle switch so it has power i put the oil sending unit back in and hooked it up and it didt do anything

 

If you left the computer controlled distributor in the car and are now running a non cc carb setup, you will need an hei vacuum advance style distributor in order for proper advance to occur but if I'm not mistaken, your car should still be able to run as is. Try adjusting the timing by loosening the distributor hold down bolt and rotating it while someone else cranks the motor over and see if you can get it to start. Your better off trouble shooting these areas of uncertainty before throwing $$ at parts that might not even be your no start problem.

If you are positive that you are getting fuel to your carb, then you more than likely have an ignition issue. First make sure that all of your wires are in the correct firing order and then adjust the timing like noted above. If this still fails to start your car, test to make sure that you are actually getting spark and then report back.

 

it is a non cc carb and we have tried to adjust the timming multiple times with no luck im thinking on just buying a new HEI distributer and go from there scince i think thats the problem instead of the plug in that comes from the base my plug in now comes from the wiring harness of the car

 

Just to clarify, you've tried to adjust the distributor and start the car with no luck? Have you pulled a fuel line off of the carb yet? Are you SURE that your at top dead center and your distributor isn't 180 degrees off? The only reason I keep pushing for you to check these things is because when I did my tbi to carb swap, the same problem happened to me. I checked for fuel and I had it and it turned out that my timing was WAY off. I've started a car with a non cc carb before with a cc distributor and it will start and idle, the effects of not switching to an HEI won't even be noticed at idle. Yes you are going to need to get an Hei BUT theres no point in spending that money when you have everything that you already need to make sure that the car starts and runs in the first place! That's just my $.02, though. Whatever you decide, report back and let us know.

 

Carb has gas i have a fuel pressure gauge that shows it and we have re adjusted the distributer got the number 1 cylinder up and had the thing in the distributer pointing that way and all the plug wires should be on right

 

The rotor in the distributor should be pointing at 6:00 on a clock, or straight ahead at your radiator/front of car. Grab a spark tester, theyre very cheap and will tell you if you are getting adequate spark.

 

staight ahead??? i was told to get the number one cylinder all the way up and have the rotor pointing at the number one cylinder..

 

Woops, I meant to say the rotor should be pointing at 6:00 on a clock, or straight ahead at your radiator/front of car OR before, say anywhere from 4-6 on a clock. Technically, the rotor can be pointing anywhere, as long as you put the spark plug wire for cylinder 1 on the distributor cap post that the rotor is pointing to when at TDC. Now, are you SURE that you found TDC of cylinder 1 on the compression stroke and not the exhaust stroke? The piston will come up twice, you should pull number 1 spark plug and put your finger in the threads of the hole while someone else spins the motor. When it comes up once, you will feel air being pushed out of the hole at your finger. When it comes up again, you will not feel any air. On the compression stroke, which is what you are looking for to set TDC, you want to be able to feel the air. If you do not, you are on the exhaust stroke and will want to spin the motor and bring #1 up again. Use your timing marks located on the top of your harmonic balancer as well, if they are readable. You will want to align your white line on the harmonic with the "0" mark.

 

im almost starting to think now maybe the plug wires r off but if all were say to the left 1 to far it still shouldt back fire. im not sure the next time ill be able to work on the car this is just very frustrating after putting a $4000 motor in it

 

The #1 piston comes to TDC twice for every rotation of the distributor.

You could be in the #6 firing position, or the #1 firing position.

 

still no luck if we dont figure it out tonight i might just take it somewhere to get fixed, been at it over a week with no luck at all

 

Tell us what you have tried thus far..Have you made sure that you were correctly at TDC like previously suggested?

 

Okay im 99% sure we got the timming figured out but it still wont fire we gaped the plugs right and it wanted to run but it would its the closest to running we have had it so far we pulled the plugs and found something werid it seems like the back two plugs on each side seem to be getting gas and the front ones arent at all or are getting very little... the car is up on ramps but i dont think that should matter at all to make the gas only go to the back plugs

 

just because I am curious about why, I have to ask.. You have an EFI fuel pump that is trying to keep the fuel line at 43 psi by the regulator and you have a carb that requires 7-9 psi. I have been told that the line size is a major player in this also. Is the fuel pump too much? Alot of people don't understand EFI so they switch to Carb, which IMO is a huge mistake. But, to each their own.

 

i have the stock fuel pump because i really dont wanna drop the tank and the regulator set up should work and i know its not at to high of PSI because of the gauge. and i switch to carb exactly because of that i guess carb is something i can handle plus i have vortec heads and would need a vortec intake for the TPI

 

Is your new pump going to be able to suck fuel though the GE rotor pump already in the tank ? That is an experiment I have never tried.

 

im using a return style regulator not a pump off the motor im still using the in tank pump

 

Are you using the Mallory 4309 regulator? And your sure the return is hooked up correctly?

 

By the way, did you ever test for spark? That would and still will eliminate a ton of this guess work for ya.

 

its a aeromotive one and yes i tested every plug to make sure it did

 

Well if it's getting fuel and spark but not firing then the spark must be being delivered too early or too late, a timing problem but you've already been down that road...hmmm

 

well figured out one reason it wont start myuncle adjusted the rockers or valves cause they seemed really loose and that was a big mistake engine builder said he already had them where they where sapouse to be and that if to tight like they probly are it wont run so we coulda messed up a valve or push rod... seems like everything that can go wrong does ... might just sell the car or trade