acm123

Hello Guys,
Well this little project of ours is becoming kind of a headache. Lol.. we have a no start condition on this vehicle and after following the directions and diag procedures listed here for the relays

http://www.electronikrepair.com/page6.html

d. Testing the fuel pump circuit: The circuit from LH Pin 20 goes to the Fuel Pump Relay pin 85, check for continuity between these two points. From the Fuel Pump Relay pin 87 the circuit passes through fuse 42 then to the fuel pump motor. Pull the fuse, check the fuse, and clean the connectors. Check the continuity of this path. Bridge Fuel Pump Relay socket points 30 and 87; the fuel pump should run. If the pump does not run, check for battery voltage at the "+" terminal of the fuel pump and check for a good connection from the "-" terminal to ground.
BRIDGED THE 30 AND 87 AND FUEL PUMP RUNS
e. Check for Voltage to Relays: There should be 12V (nominal battery voltage) at the fuel pump, EZK and LH relay pins 30 at all times. This same circuit connects to LH connector Pin 4, check for 12V there too. If there is no voltage, check the + battery connector, which is the point where this circuit begins. TESTED ALL PIN 30'S AT RELAYS AND ONLY READ 8V SAME AT PIN 4 ON THE LH CONNECTOR.

f. LH to Relay connection test: The LH relay pin 85 connects to LH connector pin 21, check for continuity between these two points. CHECKED FOR CONTINUITY BETWEEN 85 AND PIN21 OF THE LH CONNECTOR CHECKED OK

I am puzzled where to go next and what to test. Why would I only be 8v.. Is there a power distribution block or something that would be causing such a large voltage drop??


Any assistance would greatly be appreciated :-)

rnixon

When you measured the relay voltages, what were you using as ground? I'd check that ground.

acm123

Hello guys,
my mistake it looks like the voltages are ok since I used my voltmeter instead of the test light :-). They are reading battery voltage.. 12v.. humm and other ideas of what I should check?

Thank you

Alan

Try to start with the fuel pump jumper in place...

What happens?

Alan

jtrygstad

I had the same situation last fall with my "new" 89GT. Checked all the easy stuff. New relays, etc. Jumped the fuel pump, but that didn't work either. (BTW, put a pressure gauge on the fuel rail - wish I had done that first). In the end it was a failed ECU (unfortunately, too common). Replaced it with a Speake unit. Fired right up.

FiveElements

slowly take the cap off the fuel loop and see if the fuel pressure is there. It's right at the font of the engine under the plastic cover for the fuel injection loop. The fuel pump might run, but that does not mean it's working or pushing fuel correctly.