NO power to TBI

[redrock82002]

HI all,
last night I wired in a ez tcu for a 4l80 I put in my suburban. before I started, my burb would start almost instantly, but after the install I cannot get the truck to turn over without spraying starting fluid in the throttle body. For some reason I have no power to the fuel pump nor any power to the injectors. I ran juice straight from the battery to the fuel pump plug and it lights right up. they only thing out of the ordinary that happened was the hot wire to my cig plug arced on some metal when I was repairing it.

I have checked all the fuses in the fuse block along with every other one I could find and they all checked out just fine with power to both sides.

I checked what I assumed was the relay for the fuel pump (passenger side firewall) and it had power to the large orange wire.

I did some research on the site and found info on the ecm plugs and to check for constant power to B1, and C16. the thread stated that A6 should have keyed power which it did not have.

during the install i did tug on some wires trying to arrange the mess but I didnt pull hard enough I feel to break a wire.

Any help would be great. the deer hunt is in two weeks and I need this baby running so I can haul the camper to the mountain.

thanks

 

[1low4x4]

Isn't on a TBI, you have to have spark to have fuel? When you wired the tcu to the ignition system did you mess something up there? I had the ez tcu for a 4l80e and I'm trying to remember how it all went together.

 

[redrock82002]

The only 2 connections to the fuel system were the tps plug and a tach signal from the negative side of the coil. The rest was a wire to both sides of battery, a keyed 12v wire, and two plugs to transmisson. The rest are not yet connected yet since they are not required for normal operation. The truck will start when sprayed with starting fluid so there is spark.

 

[1low4x4]

The only 2 connections to the fuel system were the tps plug and a tach signal from the negative side of the coil. The rest was a wire to both sides of battery, a keyed 12v wire, and two plugs to transmisson. The rest are not yet connected yet since they are not required for normal operation. The truck will start when sprayed with starting fluid so there is spark.

Yeah I missed the part about the starter fluid, so if it has spark, then fuel should follow on the TBI. You said you had power to the fuel pump relay but not at the pump? I'd get out the book with the wiring schematic and start the process of elimination with your meter or test light. Might look for any blown fusible links, not sure there are any on the fuel wiring but it's a thought.

 

[yevgenievich]

Does fuel pump runs when power applied to test connector at thw relay? Is there a switched 12v coming in to the relay

 

[redrock82002]

Yeah when I get off work, I'm gonna chase wires with my meter, not very versed with using one so it should be fun.

On the relay there was a test port that i tried to send power thru but could not gst the pump to run i'm gonna doube check which wire had the power when I get home

I'll let yall know what I find.

 

[redrock82002]

So i rechecked the relay before I left for work and I am only getting power to the orange wire, there is no 12v switched source at the relay plug. I sent 12v to the test plug running from the relay (red wire) and nothing happened.

you know Ill be chewing on this all day at work now. I hat leaving things unsolved. lol

 

[yevgenievich]

Switched 12V will be at the relay only for couple of seconds when key switched to on position and it should be on when engine is cranking. But the pump should run if power applied to test connector. You might be getting a signal to the relay, but appears to be either a break in the wire from relay to pump or grounding of the pump

 

[1low4x4]

Yep, what he said. Sounds like problem between relay and pump

 

[redrock82002]

Fixed

Well it took a new relay to get the pump to spin. To get the injectors power,I chased my ecm 1 wire (pink, with black stripes from the fuse box to the splice on passenger side of engine, and discovered it had worn thru the sheath and contacted the intake. Thanks for all the input.