Tyanez74

Hi Everyone. I am having a problem getting my IROC started. It’s 5.7l TPI and it cranks but no start. I have changed the fuel pump out and the fuel pump relay. Still only says 20 psi fuel pressure. I have checked the fuse located on the inner fender near the battery and all was good. I have tried testing the pump by jumping the ALDL and the pump kicks on although when I turn the key forward, the fuel pump doesn’t kick on. Any suggestions on what to test next? Oh and forgot to add that it will start with a shot of starting fluid. Definitely fuel related.

_the_ragged_hat

Hey Tyanez, Is your car equipped with a VATS Security system? Should be able to tell by looking at the ignition key. If it does it will have a black rectangle with rounded ends (Stadium) with a silver line in the center. If this is present, You may have a faulty lock cylinder or bad wiring to it. If this system has experienced a failure it will isolate the fuel pump relay via the ECM and it will not send fuel to the engine for starting.

Tuned Performance

iTrader: (92)

vats will not kill fuel pump relay control. what year is this ? The ecm controls the fuel pump relay for prime on the relays green/white wire.

Tyanez74

Thanks for the replies. I do believe it is equipped with VATS. A couple other things I may add I replaced the ignition control module and the fuel pressure regulator this weekend. Still the same. Could it be possible my ECM went out? I was able to read the codes and it is reading code 54, low voltage to the fuel pump. Not sure what next to test and hate having to keep guessing by replacing parts. Also, when I do crank the engine, after I stop cranking I can hear return fuel going back into the tank.

_the_ragged_hat

C54 Fuel Pump Circuit Low Voltage.
The status of the fuel pump signal (Circuit 120) is monitored for voltage by the Engine control module, and is used to compensate fuel delivery based on system voltage. This fuel pump signal is also used to store a trouble code if the fuel pump relays is defective or the fuel pump voltage is lost while the engine is running. There should be about 12 volts on Circuit 120 for 2 seconds after the ignition is turned "ON" or any references pulses are being received by the Engine control module. Code 54 will set, if the voltage on Circuit 120 is less than 2 volts for 1.5 seconds since the last reference pulse was received. This code is designed to detect a faulty relay, causing extended crank time, and the code will help the diagnosis of an engine that "Cranks but will not run." If a fault is detected during start-up, the "Service Engine Soon" Light will stay on until the ignition is cycled off. However, if the voltage is detected below 2 volts, with the engine running, the light will only remain on while the condition exists. (Code 54 for 5.0L (VIN F) & 5.7L (VIN 8) "F" Cars, Page 6E3-A-58 Of Dealership service manual for 1988 Chevrolet Camaro)


I Also have the trouble chart for this code, I'll upload that next.

_the_ragged_hat

I Apologize in advance for the poor photo quality.

Tyanez74

Thanks _the_ragged_hat for all that information. I will follow the diagram for testing. Do you know if there is a diagram that displays the CKT numbers?

_the_ragged_hat

Yes there is a wiring diagram, I'll take a picture of it and upload it as soon as I get home (Around 6:30pm EST USA)

Tyanez74

Thank you. _the_ragged_hat

Tyanez74

So I am getting a little closer. I replaced the pigtail to the fuel pump relay along with the relay and now the pump kicks on when I turn the key forward. Although I have the fuel pressure tester hooked up and it’s not even getting 20psi. I disconnected the fuel line and I see fuel coming out in a steady stream but not a strong flow. It’s like barely turning on a water hose. Anyways. I have already replaced the pressure regulator too. Same. Any suggestions on what to check next. Remember that the fuel pump, sending unit, and fuel filter are all new too. Thanks in advance.

Tyanez74

Any suggestions?

kestell123

Are you sure you installed TPI pump and not a TBI pump?

Tyanez74

This pump is a Delphi CFE0110 from Autozone and it it shows it’s rated at 58psi. The one before it was an AC Delco brand new. Did the same. Only about 20 psi, so that’s why I pulled the tank back down and put in the Delphi. So that’s what is bugging me. I surely don’t want to pull the tank down again if I don’t have to.

New parts:
gas tank
sending unit
fuel pump
fuel filter
fuel pressure regulator
fuel pump relay
fuel pump relay pigtail
ignition control module
new battery

Abubaca

iTrader: (3)

I'd wanna check and make sure I had good voltage back at the pump. Like verified at the pigtail under the car, not under the hood at the relay. ...I'd also wanna confirm pressure coming OUT of the pump as close to the pump as possible. You could have a kink or blockage in the line somewhere.

Tyanez74

Thanks for the reply. I checked the voltage at the connector where the pump plugs into and with the key forward it’s 12 volts and when you crank the car it goes to 11 volts. I checked for kinks and I don’t see any at all.

any recommendations on a pressure tester that I can hook up in line close to the fuel pump?

Abubaca

iTrader: (3)

I knew you were gonna ask that! Honestly no, I'm not sure the best way to do that. I bet you could cobble together some adapters for a few bucks at the hardware store though. I don't have the specs for what you'd need off hand.