1992 toyota pickup 22re. Will not start. no power to fuel pump, jumped from battery to fuel pump and started once but have not been able to repeat this, it just cranks and does not fire. Changed circuit opening relay and swapped starter and efi relays to test and the engine cranked [leads me to think the efi relay is okay since they seem identical]. Read that air flow meter controls ground signal to circuit opening relay but do not know how to test this. Is it possible that coil igniter is to weak [am getting spark at both distributer and spark plugs but it seems weak] to close relays? First thing I did was new fuel pump; not very good diagnostics.
Hi and Welcome to Just Answer! My name is XXXXX XXXXX I will do my best to help.
First, install circuit opening relay back, as it is not the same as EFI or starter relay
it is possible that you have low spark, but this will not cause relays not to operate.
to check Airflow meter use Digital volt meter set to Ω-ohm checking. test as you touch both leads to each other, meter must show 0.00 or 0.3 Ω- which means there is continuity. go to Air flow meter and use needles to back probe wires at pins 1 and 2 - respectively brown and green yellow wire. make sure you have good contact
at this point meter will show no readings- meaning open circuit (normal state) have someone to crank the engine as you observe meter, once engine is cranking meter must show 0 to 1 Ω meaning that sensor is working fine- this is how you test this circuit
if all good go to next step, if not you can bridge the two wires temporarry to by pass air flow meter.
next or maybe start with this step is to check EFI fuse
use test light to check for power on both sides of the fuse - must have battery power all times. if not check connection between fuse box and battery- there is fusible link
if all this is good, check if you have ignition power to EFI terminal coming form fuse -IGN using test light check EFI relay, you must have one constant power and one ignition power
if no ignition power comes when key is turned to ON position- then check IGN fuse - if fuse is good, check if you have power coming out of ignition switch on black and red wire
if no power to blck and red wire or power is weak- replace Ignition switch
and check ignition switch power supply
if there is something you do not understand
Hey Pavlin, My initial problem is no power to the fuel pump, cranking or not. I tested this at 2 points. I have jumped from battery to fuel pump plug beside tank and from the battery to the blue wire in the plastic casing on the passenger side floor [right where it goes from 2 blue to 1 blue wire; I was searching for broken/shorted wires] and the pump started both times. But with normal circuitry I get no power at either point where I jumped to. I guess I did not make myself clear as to my relays; I replaced the circuit opening relay with a new one. I switched the efi and the starter relays [because they look identical] just to test the efi in the starter position and the engine cranked. This indicated to me that maybe the efi relay is functioning, let me know if I'm missing something here. I have checked the efi fuse and every other one in engine fuse box, driver's side fuse panel and the 2 below the circuit opening relay and all are ok. I have a question as to the 2 blue wires combining to 1, I assume 1 is for the cranking fuel pumping and the other is for pumping with the engine running. Is this so and does the air flow meter control both? And how do I get into the meter,from the underside, through the plug or by cutting through the silicone around the horseshoe-shaped black plastic piece on top of the air intake housing? You say to check the "connection between the battery and the fuse box-there is fusible link" and I don't understand this, there is no visible fuse between the two. As far as the ignition goes, doesn't the fact that I can constantly turn over the engine and have spark [though it seems weak to my untrained eye] mean that ignition is not a problem?
EFI relay supply power to Circuit opening relay, which is activated by air flow meter. you must check first id there is power to circuit opening relay from EFI relay on the white and red wire. power to pump will come after engine is cranked or running. measure fro ground signal at circuit opening relay, then you will know is air mass sensor is working. you can also ground the relay for testing. no need to spend time to go to air mass sensor for now. do you have test light?
please click here to see wiring diagram- if car does not run when fuel pump is powered, it means there is more than just power to pump. you will see on diagram blue wire splits to go to diagnostic connector. please verify we have power at circuit oppening relay white and red wire with engine cranking.
Okay Pavlin, Hey my apologies for the delay in answering, had to help a neighbor and was away from the computer. I will be sitting by it constantly until we finish with the diagnosis. I unstrapped circuit opening relay to expose the feeds to it and got power to the white wire with just key on and when cranking and no reading on the red wire when key on or cranking. The first time I jumped from battery to plug next to fuel tank I was able to start engine. I was not able to in following jumps but hope that solving this problem will lead to solutions.
Pavlin, In looking for green/yellow wire I find a fried and broken wire that connects to the center receptacle above where the red and white power feeds are. I think at the base of it I see maybe green/white or yellow insulation. Is this a shorted ground and how can I repair it? Must they be soldered on or is there a slide on fitting?
okay I exposed the wiring on the engine side of the firewall and want to pull back on the proper wire. Is it a green wire with yellow strip or yellow/green.
It has disintegrated all the way back to the firewall so I want to pull it back toward the front of the truck so I can identify which wire I need to splice to thread through the grommet and into the circuit opening relay. Also the fitting in the housing of the relay, do I push it through to the front of the housing [the side where the relay mounts] or does it pull back out toward the burnt wire side?
As I said, the broken wire had disintegrated all the way up to the firewall and right to the fitting of the circuit opening relay. I need to be able to identify exactly which wire I am going to connect to in order to jump to test or to fix. Have tried to find continuity between remaining end near sheaf at firewall and the green/yellow and yellow/green in bundle near fuse box but cannot. May be because the remaining wire is so brittle but could be poking my needle probe into the wrong wires.
use diagram to identify wires. if this is the only broken wire there then this is the wire, you can wire this relay terminal to direct ground briefly. relay must click when key is in ON position.if relay click when grounded at this terminal. crank and attempt to start,
I don't think my model is an SR5 so the diagram is not exactly like mine, however since the middle port for receptacle is the ground and the shorted wire, according to the diagram you sent i should be looking for a wh/red wire by the fuse box. If you can find another diagram please send.
This is what I assume the diagram means with relation to # XXXXX ports and these are my colors:
3. black/red 4. broken wire 5.yellow/orange
1. white 2. red
From the diagram I think #3 goes to starter and #4 to the air meter. #5 looks to be the middle port and the ground, where is it grounded to and what color is it when it gets there as this is my burned wire?
all diagrams are same for all pick up trucks. black and red goes to starter
White black is ground. Green/yellow is ground from mass air flow(ground), blue goes to fuel pump, white and red is power supply.
So white/black is probably my broken-burned wire, but where does it go to ground? The joint sheaves at the firewall are near impossible to get to.