4age smallport injectors not firing

[mark01]

Hey, I've done a search but haven't been able to find what I'm looking for.

I have a Starlet KP61 rally car that I recently put a smallport 4age in.

It was running until I put it on a trailer, travelled up the country, and then it wouldn’t start to drive off the trailer.

We have traced it to the injectors not firing. It has spark and the fuel pump is pumping fuel to the fuel rail. If you spray some start ya bastard in the inlet manifold then the engine will run.

Got a multimeter, and with ignition on there is 12 volts going to the injectors, and also 12v at the end of the injector wires at the plug for the ECU. I used the multimeter and checked connectivity on the brown earth wires from the ECU and they are sweet, because as I understand the ECU just grounds the circuit to fire the injectors.

I’ve checked the 4 wires from the distributor to the ECU that times the system and they are all connected. Also did a connectivity check on the wires that send a pulse from the ECU to the ignitor and then back to the ECU that tell the ECU that there is spark and they are connected. I even replaced the distributor, and the car still won’t fire.

My first thought was that there was a wire come loose during the trailer ride, but as far as I know I’ve checked everything related to the injectors and it all seems fine, so I’m now thinking maybe it’s the ECU playing up, because I've run out of ideas. But before I try to find a replacement ECU I thought I’d check to see if anyone else maybe had a suggestion?

Thanks for any help! Cheers

[Grrrrrrr!]

My guess would be that you've got a wiring short somewhere (something rubbed thru as you drove it up country) and you've blown the injector drive circuit. There might be a fuse inside the ecu (probably soldered to the board). Pop the lid off the ecu and look for signs of badness would be my first step.

[mark01]

Thanks. The car is at the other end of the island at the moment, so I can't take a look just yet, but when I'm back up there I'll take the lid off the ECU and have a look.

cheers

[Allister S]

Hey,

Had a similar problem on a older 4AGZE with Link computer - everything checked out fine but still no fuel coming out. Car had been sitting for quite a while.

I ended up just taking a wire that the Link should be earthing and sparked it on earth - I believe the injectors were stuck and this "longer" duty cycle unstuck them.

Worked fine after this... Bit brutal but shouldn't hurt injectors.