Mjedi

My 86 na FC starts and runs for about 2 sec then dies. To start, it’s a newly rebuilt the motor that I built that used to run during the initial start up (as long as I keep my foot on the pedal), because of poor idle and timing was off. I replaced the old injectors because my exhaust was running red hot (this was probably a timing problem), but I could get it to run afterwards. So I went back to the old injectors with new injector grommets. Ever since then, I can get it to run for more than 2 sec. I thought it was a vacuum leak so I replaced all of the vacuum lines and the gasket between the upper and lower intake. Compression was good and the fuel pressure was 60 psi (new fuel pump) and held at 20 psi about couple of minutes. I tested all the injector and they were reading about 2ohms. Check the fuel system solenoid and the ignition coils. What am I missing?

evo_koa

iTrader: (2)

maybe iac valve?

Mjedi

IAC valve?

satch

iTrader: (1)

Did you dead head the fuel pressure gauge or was it inline? I would assume by your reading that it must have been dead headed. Secondly, have you tried jumpering the fuel check connector? This will bypass the fuel switch in the AFM which might be faulty. Have you verified that the flapper door to the AFM is opening up when starting? If it does not the engine would have a very hard time starting and thus running. A large vacuum leak can cause the door to not open besides it just outright being stuck. And are you sure you didn't mix up the fuel supply and fuel return lines when installing the motor?

Mjedi

I connected the fuel line from the pump, straight too the fuel gauge with the ignition 'on' and jumpered. But the manual says 60 psi is on the low side (64- 85 psi) so I was thinking about replacing the fuel pump. AFM? (air flow meter) I haven't checked it, but since developing this problem I haven't connected the air intake duct.

satch

iTrader: (1)

Then if the front of the AFM is not connected you should easily be able to verify if the door is opening or not.

Mjedi

It's not stuck. I can feel opening and closing freely, but how do I check it (being be myself) while starting it up?

satch

iTrader: (1)

You can try to prop it open a bit and go from there. And you have the AFM connected to the throttle body?

Mjedi

That did it. My 13b lives again..... THANK YOU SATCH

satch

iTrader: (1)

What did it? Was it propping open the door or connecting the AFM to the throttle body?

Mjedi

Connecting the AFM back to the throttle body, but i think moving that flap open and close helped. So tomorrow I getting to work the flap and timing the motor.

satch

iTrader: (1)

Yeah, the car cannot start w/the throttle body just exposed to unmetered air like that as it's too much air for the engine to deal with w/o the AFM feeding information to the ECU so it can make fuel corrections.

RotaryEvolution

iTrader: (30)

and the AFM also has the fuel pump switch inside it, if the door remains closed due to no air passing through it then the pump will not run.