Pondboy

I searched the forum and didn't find my solution so here is my problem. I swapped my engine and it is all in except I haven't locked all the accesories down or the timing because it hasn't cranked yet. I has tried two/three times so i know i am getting spark. I disconnected the fuel lines at the tank and turned the key... no fuel coming out of the line. I swapped the pump and nothing. The relay (under the hood) is clicking when you turn the key. The fuel pump fuse is NOT blown. I tested the pigtail at the pump and have no power. When I swapped the engine, i didn't do anything to that part of the wiring harness. I checked and it doesn't even go up into the engine bay, it goes in the cab. Please let me know what you all think.
I wish we had a Smilie that showed me bashing my truck with a rock!

myyota

It would help to know what year truck your working on and what engine it has ???.

Pondboy

Oooops, sorry. In my head i said all that. Really pissed off right now.
1994 pickup with a 22RE

myyota

If your sure the fuel pump and fuses are good, check the core relay, if its bad it won`t send power to the fuel pump.

snobdds

Plus make sure your AFM is hooked up and the flapper door is operating like it should. It sends a signal to the ECM that tells it to send power to the fuel pump. There is a AFM check on 4crawler's web site.

I don't know if the AFM is year specific, but I would also check/research that whole system to make sure it is operating properly.

Pondboy

Core Relay is under the hood, in the fuse box on the right fender right? That relay is clicking when the key is turned. I don't know how to check a relay other than that. I am researching the AFM thing now.

Pondboy

ok, i can't find it....what is an AFM?

EDIT: Air Flow Meter

Pondboy

in reading through this page http://http://www.4crawler.com/4x4/CheapTricks/AFM/index.shtml it appears that this condition would only apply once the engine is running. My engine gets 0 fuel and isn't firing at all. The engine has bumped off of vapors so there is spark and such. I will play around with the plug anyway because it is the only thing that I did disconnect in the install process that has anything to do with the pump. Please keep the ideas coming.

Pondboy

Post edited. I found the info on my own.

myyota

The core relay is in the cab, above and to the right of the computer. The AFM is mounted to the air box and has a large electrical plug going to it.

Pondboy

I am going to check the relay today. Like i said, the big plug on the AFM is the only thing I "touched" in the install. I will read up some more on playing with that first.
Is there a way to "check" the relay? I usually just listen for the click as it opens/closes.

myyota

Ive never had to test the relay before, but look in the service manual, it tells you how to test the relay.

Pondboy

Assuming that I understand all the posts, I found the "Circuit Open" relay above my ECU. There is no water in it or evidence of water near it. There is a wire that matches (white w/black stripe) the wire on the Fuel pump. What I can't find is how to check the relay. I have been looking through the service manuals but no luck yet.

The diagnostic port has a lot of patina/corrosion. Is that an issue? I don't know how that happened, truck has never been wet like that.

4Crawler

iTrader: (3)

From the FSM:
- http://www.4crawler.com/4x4/CheapTri...ORelayLocation

Pondboy

ok, I have reached the end of my patience. I started swapping the engine in March. July and it still aint running. I tested continuity on the fuel pump wire it was good. CO Relay is switching (heard it with dash pulled down) all fuses even it they don't apply are fine and all the fusible links. I don't know how to test the actual relay but its over. I am having it towed tomorrow. Thanks for all the suggestions. I will be sure to post what the solution ends up being.

I admit defeat.........

4Crawler

iTrader: (3)

See the link above for "how to test the CO relay". It is all there. Relay clicking means the coil inside is intact and getting power. Click sound is from the internal steel part getting pulled to the magnetized coil in reaction to the current. But the contacts may be pitted or dirty and not sending power to the pump or there may be a problem with the wiring to the pump, power or ground side. Easy enough to check for good power at the pump.

Pondboy

Thanks, I checked the power side from the relay for continuity and that was fine. If the sensor/flapper on the intake wasn't working, would it prevent the relay from sending power to the pump? I tested the wire from the relay to the pump while i tried to turn the engine over and had no voltage even though the relay clicked.

4Crawler

iTrader: (3)

AFM contact turns on the CO relay:
- http://www.4crawler.com/4x4/CheapTri...shtml#FuelPump

Power comes from the battery via the fusible link, EFI fuse and main relay as shown on the diagram on the page above (or below):


Fuel pump test jumper forces the relay to turn on with the ignition. But of there is no power to or from the relay, figure out why.

Hadmatt54

Firstly, if you plan on working on your own vehicles instead of paying someone else to do it you had better develop lots of patience, because vehicle repair is one place where "Murphy's Law" really seems to flourish. You need lots of patience and you need to develop logical troubleshooting skills, You look at what should happen? What is actually happening? What can the cause be? Ruling out the most obvious first moving towards the most complicated.
If you are sure that the relay clicked then there has to be voltage present. It's the current flow through the coil in the relay that makes it an electromagnet thus drawing the movable contact in to mate with the stationary contact. If your voltage measurement was across the contact and it was closed you won't measure any voltage, both sides of the contact are at the same potential. Always take your voltage measurements to a known good ground, if you really want to be sure you have a good ground connect one voltmeter lead to the negative post of the battery. I know voltmeter leads are not that long, but a good addition to your tool box is a couple of test leads about 12 feet long. one red and one black with small insulated alligator clips soldered on to each end. Most electronics parts stores sell test lead by the foot and they sell the clips individually.
Did you jumper the fuel pump check (test) connector to see if your fuel pump works? I don't recall seeing it in any of your posts. In your truck this closes the contact in the AFM and sends current through the COR to power up the pump. If you tried this and nothing happened then you need to rule out a pump problem first. Assuming that your grounds are all good run a 12v source directly to the colored wire (most of the time it is blue, the white/black wire is the ground) that goes into the pickup assembly of your tank. Put an inline fuse in this wire for added protection. Make your solid connection at the tank and touch it to the positive post (you do not want any sparks near your tank just in case there may be some gasoline vapors. If your fuel pump is okay you will hear it and you will be able to hear fuel moving through the feed and back to the tank through the return line. Now that you have proven that your pump is okay, you need to check for continuity from the COR to the tank, if it doesnt test, there should be a plug under the front passengers seat that you can seperate and test for continuity in both directions. Once continuity is established in the circuit, you need to test the COR as per 4Crawler's instructions.

Pondboy

Why is it always something embarrassing! Hadmatt54...I did even replace the fuel pump and run a seperate wire to both fuel pumps before having it towed. Well, after a year the Yota is running!!! I had it towed to the shop where it sat for 6 months. My mechanic was just starting RE WIRING the fuel system when he found a little bitty wire under the air intake. Turns out the computer was not turning on thus neither was anything else! That little wire was the ground for computer, I had no idea the computer grounded to the block. As many of you probably know, this wire is not in the harness which I checked a gazillion times. I hope this helps a newb like me later. Thank you everyone for all the posts, you are an awesome bunch of guys. Now that my truck is running, i look forward to question about how to customize it! "Its always the ground....why is it always the ground!"