just put the motor back in,76. F.i. so i crank it with the fuel pump on it wont start , but pumps enough pressure..to start after i Take + wire off pump , it starts no problem . And revs nice till about 4500 rpm , Put wire back on while running , Wont even go past idle ,bogs ,with a lite touch of the gas pedel. take wire off ,instantly good again I have 2 of each and checked and tried all combination , Pressure regulator , checked . they both open at 30lb.s , double relay , both are same function All vacum is where it should be , afm box hooked up etc. bought a new sensor installed today , when i connect it with the engine running , it dies instantly same as last sensor... i know it could be many things but the fuel pump bit and sensor is weird Injectors? Any ideas??? thanks so much for the help. gas tank was cleaned out too.. new filter all new lines inclunding all rubber in firewall etc.
I would suspect that the earth connection for the fuel pump is shared with some sensor on the FI so when current flows through the pump and through the shared earth there is a voltage drop so the sensor reading apparently changes. Clean all the FI earths or return the fuel pump earth somewhere different as an experiment. Bad earths are known to cause some FI problems.
will try thanks . soome mentioned the fuel injection ground on the motor . but i never took that off after the redoo of the engine , david roberts is lending me a air box and the computer to try and see if it is that ...! thanks dave . !
Its all factory so i have to say no, I read something anout putting a relay , but not sure what its all about ,,
What sensor are you taking about, how long does it run with the fuel pump disconnected, where are you disconnecting the fuel pump, directly on the pump, is the pump wired the right way round?
Disconnecting at the pump ,, positive is lower one , or bottom . How the pumps mounted , from factory , it will idle for a bout 5 to 10 minutes without the pump hooked up ,,After i crank it with the pump hooked up to prime for five seconds or so... Head sensor ,,,
