I got the TBI 350 into my 1973 camaro and have it all hooked up. I have a painless tbi wiring harness on it.

When I turn the key on the fuel pump goes on for a couple seconds to, i guess, bring the fuel pressure up. Then when i turn the key on to start it, it turns over but doesnt fire up. No fuel comes out of the injectors. When I stop turning it over but leave the key on the fuel pump comes back on for acouple of seconds. Sometimes a drop or two of gas will come out of an injector when I stop turning it over. There is gas coming out of my return line though.

Does anyone know what could be the problem? Maybe the fuel injectors are bad or maybe not enough fuel pressure? I have an electric 14 psi fuel pump which is mounted near the bottom right side of my firewall. Is this not enough pressure? I know TBI needs 9-15 psi to run right but maybe the fuel pump is too far away from the tank to make enough psi. If there isnt enough pressure would the gas not come out of the injectors? I checked for trouble codes but there arnt any. The oil level is good. Maybe the oil pressure is too low or maybe the oil pressure sensor is bad. Also I dont have any coolent hoses that fit right now so there isnt any coolant in it, could that be it?

Any suggestions or tips?

 

[:'(] although i cant seem to find my GM tbi book at the moment the fuel pressure seems too low, you must also consider volume. GM fuel injection systems are recycling in that they move alot of fuel to maintain a constant pressure(35-50 comes to mind for tbi??) alot of people use the donor vehicles in tank pump and sending unit assembly, this also has the required return port. is this an aftermarket racy race pump?? most pumps are pushers and prefer to be mounted close to the fuel source. your computer is working in that its cycling the pump with key on, does it continue to run while cranking?? can you get a fuel pressure tester ?? the stock lines have test ports. also a noid light will let you know if the injectors are firing. the computer has no capacity to know if any coolant is present only the temp of it.. try starting the car with a little gas down the throttle body if it fires then fuel is definately your problem. i cant tell from the description if your fuel system is complete and proper to make it work on a tbi set up, maybe a little more detail on the fuel system would help us kurt

 

I have sprayed starter fluid into the throttle body and it did fire up. Every tbi book, including the painless instructions, say tbi uses 9-14 psi.

Right now i have the metal stock fuel line cut under the passanger seat. The from tank part is then connected to a little piece of rubber fuel line where it then goes into a fuel filter (placed correctly with flow of gas). Then there is another rubber fuel hose going from the filter up to the lower passanger side firewall where the fuel pump is mounted. Then a rubber fel line goes from the pump to the metal fuel line attached to the motor which then goes to the throttle body. The return line is another smaller diameter metal fuel line on the motor which then connects to a rubber fuel line which currently goes into a little plastic gas tank because I havnt ran it to the back yet. Im to move the fuel pump to under the passanger seat on the frame rail.

 

also, there is as getting up to the throttle body but im not sure about the pressure. would gas only go through the injectors if its pressurized enough?

also, i ont think the fuel pump comes on when i turn it overbut i will check again

 

I just checked the fuel pump and it does come on when i turn the engine over. I also checked the fuel injector connectors and when the key is turned in the on position one of the two wires on bothconnectors have electricity (is there anything else i should check for?)

 

Check for ground with a noid light or LED test light at the injector wireing. That would be your singal to them. If you have no signal have the ignition module checked. Your pump pressure should be fine. Your pump volume if its not enough will cause poor running.

 

what should i do to check the ignition module?

 

i used a test light on the injectors and when the key is in the on position one wire on each injector has power, then when i turn the engine over the power goes off and each injector is completely powerless.

 

Well that sounds like a problem there. Power should always be on. Its the ground that tells the injector when to spray. I will search a diagram in my manual.

 

The power to each injector comes from a two fuses. (one each) Its suposed to be hot in run and start. Then the ground side of the injectors go to the ecm which gets it signal from the module to deliver the pulses at the right time. Maybe youi have power to the injectors hooked up in the wrong spot. Did the painless tell you where to hook those wires up? I did a 350 TBI in an 87 El Camino with a painless but forgot what I did.