Not getting power to injectors. Anyone ideas?
 

I have been getting the 7 together after being down many of years. I installed 400lph pump, and have 1600 secondaries that will be installed AFTER i get running. Although I can not get her to crank up. Pump turns on (its loud) checked fuel pressure to primary fuel rail (its definitely getting there!) but when trying to crank no start, pull spark plug absolutely NO GAS on plugs. If we spray brake clean in throttle body it will ignite and get a nasty loud exhaust firing. Swapped out primaryies with a second set i had laying around but same result. then used test light to probe injector wires and getting GROUND pulse to wires but absolutely NO POWER to injector wires. PFC ECU just came back from Apexi and everything check out good with them on bench test ad everything looks good on our side connected to computer. Just wondering if anyone else has ran into this same issue and what the fix was or any other ideas what to check for/on? I have been told to check the EFI main relay switch which i will do next time i get a chance to look at the car, another opinion from someone was the ignition switch but i would imagine if the ignition switch was bad it would let the car try and crank (i might be wrong). Any help and suggestions would be greatly appreciated. Thank for your time.

-Jason :scratch::scratch:

The injectors get their power from the ECU.
First and foremost, check the service manual to track the power wires specifically.

The EGI fuse in the engine bay is the fuse for the ECU. Ensure it is not blown.

Do you have a power commander and is it lighting up as normal?

If so, then the ECU is getting power. From there, you need to test continuity from the wires on the injector plugs back to their source.

Sorry but nope. The ECU triggers the ground side of things. The main relay feeds battery + to the injectors and the voltage to the main relay comes from the 30A EGI fuse. The main relay also provides +12 volts to the AIR PUMP relay,ECM PIN 1B, the solenoid valves, and electrical load control unit.

Measure for battery voltage at the data link connector B+ point with the key in the IGN position. If you are good there then the main relay and EGI fuse is ok. I would suspect youR problem is at connector X05 or the harness between that and the injectors....

ditto that, check the easiest first and make sure you didn't remove the EGI fuse and forget to reinstall it.

next on the list is be sure the gound terminal is bolted to the rear rotor housing at the fuel rail/rats nest. that is the ground that the ECU uses to pulse the injectors.

Dammit! And I hate mis-information. Sorry about that, I should have called it as I "beleive". Thanks for the chime-in guys!

Check voltage at the main relay first. Make sure it is switching on and that 12V is coming out of it.

Wow great amount of info thanks guys. ALSO would these test results procedures change being I'm running parallel set up with rats nest deleted? I will test all the previously stated possibilities on Wednesday.

fuel flow has no bearing on injector signal.

but if you have it all ripped apart, check to make sure the rails are getting the proper pressure.

When we unscrew the bolt for the rail there is plenty of fuel pressure there. Although i do not have an exact reading of pressure

Okay found some fraid wires in the harness where meets the ecu repaired them thinking x02&x05 wires. Injectors fired GREAT........but now the fuel pump doesn't turn on when you turn ignition to ON position. Checked relay and fuse both good. Had to jump it in the diagnostics port to get engine to start firing. ANY IDEAS WHY THE FUEL PUMP ISNT TURNING ON NOW? ????

+1

Also, have you applied voltage to the pump connector itself to be sure that the plug isn't bad or the pump didn't coincidentally die?

Did not test pump relay with multi meter. Did hear and feel relay click though. Did not test for plug power at top of tank although why would it work before but no longer? What would have changed? Stock fuel pump with did not do a fuel pimp rewire kit.

Pump can't be dead if it works when jumped in diagnosis port. Also don't understand why plug to the pump would be bad if the pump runs and works when jumped.

UPDATE ANSWER FOUND:

1: minor stripped wire in ECU harness right near the Power FC.

2: Mostly contribute issues to this: Eccentric shaft sensors bad connection on the plug. unplugged, cleaned off, Started right up!

Thanks for all the input guys.

Which wire was stripped by the pfc? I'm having similar problems to yours.

My 2 e-shaft (crank) pos sensors had a break in the wire right before the plug; repaired those and added few extra engine grounds and still no life from the fuel pump(supra fp, stock wiring till I resolve this problem). I do hear my fuel pump relay click with key on. Also I am getting spark so I'm assuming the crank position sensors are working.

Thanks in advance.
-Dan

The wires repaired were x02 & x05 wires. Have you checked to see if your fuel pump is good?

I havent jumped the fp yet, I'll test that tomorrow. Which pins did you jump in the diagnosis connector to power the fp?

Thanks for the reply.
-Dan

Fixed it... Rewired the FP and I had the fuel lines backwards in the bay :P

Thanks again,
-Dan