iwilder

I haven't been able to find the circuit opening relay. it is supposed to be under the kick plate on the passengers side. I removed the glove box and found two identical black relays side by side. These are above the ECU. Both are number 90987-04002. Which I believe are AC or blower relays. The don't look like the relay shown in the service manual. There aren't any other relays in that location. I know others seem to have found this relay but I need some help. This image shows the relays I found under the kick plate on the passengers side.

Any help in locating this relay would be appreciated.

Thanks,

Ike

hodgi

Mine's a 4cyl, but it's on the passenger fender, close to the firewall.

pete f

In my 89 3.0 It's right above the heater relay with a metal bracket on it.

DeathCougar

iTrader: (23)

its bolted to the "A" pillar above the ECU. Should be behind that relay block, though I have not seen that style block on the pass side before.

Elvota

Try looking higher, just above the relay block you took a pic of.

In my '90 the COR was all by itself, with 5 wires going in... so a little different from your run of the mill relays.

Out of curiosity, why are you trying to find the COR?

iwilder

I started an earlier thread on the trouble I have had with the engine not wanting to run. https://www.yotatech.com/forums/f116...oblems-129911/.

I will try looking up higher but the photo that I took is up about as high as I could see in that area. The photo is of the area behind the glovebox.

I have checked just about everythig else so I wanted to check this as well. The VAFM had a problem as did the EFI relay. I removed the pump which is new and checked it just to be sure and it is working fine. I get about 60 lbs of pressure in less than a second when I apply power.

The problem occurs when the sngine is accelerated, It looses fuel pressure and then will stall. There is about 10.4 volts to the pump when it is cranking. I haven't been able to check if there is a drop in voltage when the fuel pressure drops. I'll have to get it back together and see if I can figure out how to measure that.

Thanks for the help

Ike

I went out and double checked and there is nothing above this relay block. I checked the passenger side and found a relay there above the fuse box but not the COR. I can't find anyhting in the engine compartment thst looks loike it either. All the CORs I have seen pictured had cicuit opening relsy written on them. I checked all the other threads here and didn't find anyting helpful in locating it.

Thanks again

Elvota

My COR was on the passenger side, right near were you are looking. With the glovebox (and attached speaker panel) off, it was sitting there all by itself. Dark grey, if that helps.

Here is a pic of the '90 COR plug for reference. I used a 3.4 COR during my swap and left the 3.0 COR just hanging out :



I just got done swapping a 3.4 V6 into my '90, so I have been scouring the EWD for several weeks now and I don't think a bad COR would cause the problems you are describing.

On the '90, you trun the key on to IG2 (ignition) and that powers up the EFI relay. The EFI relay then sends power to the COR. The COR turns on the fuel pump and starts sending 12v to various components related to the engine.

If the COR stops working, you'll never get fuel, the ECM will most likely stop sending signals as well.

To verify the COR is working, check pin 2 (G-Y wire on the '90) at your AFM. That should have 12v when the key is at IG2. Also, your fuel pump should come on, which you will most likely be able to hear. My COR would click as well, but I could feel it (between two fingers) more than I could hear it. A relay that "clicks" still might not be working correctly, but at least you'll know it's trying to do something.

Without reading your other thread, my guess is your TPS sensor, or a possible vacuum leak/ intake hose hole would be more likely the source of your problem. Sometimes deep in the belows of the intake you'll get a rip, and a bump or twist or the motor under torque will open the tear... causing a stumble or worse killing the motor.

I am by no means an expert, but have learned a lot from the swap and don't think a relay is going to be your problem at this point. A relay is going to work or it's not. When it's not working, your motor will just flat out die.

nate V

It sounds like it might be your vsv controlling your fuel pressure regulator. or might be a leak in the lines somewhere in the pass side. I agree that it would not be the COR. either works or it doesn't.

iwilder

Sorry I haven't replied to this thread. I was out of town for a couple of weeks for Christmas and just got back.

I located the COR. It was below the area I showed in my earlier photo. Only the back of the plug and not the replay was visible. It is mounted on a bracket secured by a bolt. The cable and plug as well as the bracket can be seen in the photo below. The COR tests out fine so I don't need to replace it but as it is part of the fuel pump circuit, I wanted to make sure that it was OK.

Thanks for the help.

Tayopa

HIO: In the first you can see the circuit for starting and running the fuel pump. When you first turn on the switch, power goes to the EFI coil, also -> starter Relay --> Circuit opening Relay prmary coil --> to ground.

It also goes from EFI contact to --> DLC b+, -and to -> the Circuit opening Relay holding coil and through the contacts to the Fuel pump. With no air flow the circuit to the Circuit Opening Relay coil is open, and it will not activate the relay because the air flow switch is not made up..

When you turn on the switch, you power up the circuit Opening relay through the primary coil. This pulls in the Circuit Opening Relay closing the contact passing B+ directly to the fuel pump. (1)

On running, the engine will close the fuel pump switch in the volumn airflow completing the circuit to continue holding in the Circuit Opening relay .

HOWEVER if the circult Opening relay primary coil is weak or bad, it will not pull in the relay, so wouldn't pass on any current to the fuel pump, hence it will not start in the cranking position, But if the vehicle is pulled at idle speed, the Fuel Pump switch in the Air flow sytem will make up the secondary pull in coil closing the contacts completing the fuel pump circuit and the engine will continue running.

When first stopped, it will start again because fuel is still in the sytem under pressure and so doesn't need the fuel pump, but as the pressure falls, the engine will gradually slow, then stop, and not start any more, unless towed at starting speed closing the switchi the air Flow circuit. .

No computer problems OK?

Tayopa

When you turn on the switch and energize the stazrting circuit, you apply power to the COR thrugh the starter relay and the clutch cutout switch to power up the Circuit Opening Relay through the primary coil. This pulls in the Circuit Opening Relay closing the contact passing B+ directly to the fuel pump.

In an emergency in the field, you can open the DCL1 test box, next to the main fuse section in the engine compartment , and jumper from B+ -> FPI. . the terminals are printed inside of the cover. This will allow you to start the engine. Once started, if the secondary coil is ok, it will keep running. Once running, always remove the temp jumper wire for you safety.. If the coil is completely burned up, you can continue back to where it can be serviced or replaced, but for your safety, alway sremove the juper because if you have an accident, the fuel pump will conitnue to load up the engine and if a fuel line is ruptured, it will pump gasonline out into the engine compartment.where it might catch fire. This is the actual purpose of the COR..

scootmonkey

Hi there,

I'm new to the site. I have a 4Runner 1990 V6 3.0 L.

Having problems starting my truck... I live in Manitoba Canada and the winters are cold and blustery. I live rurally. Back roads mostly and about 30 km from where I work.

Was driving home last week and was forced to move over (oncoming vehicle was hogging the road). Long story short, hit a patch of ice and ended up slamming into a very hard snowbank at about 70 km. The truck rolled over the bank and ended up on its wheels. Front passenger side panel is shredded. Wheels and frame seem to be okay.

Had to get towed out by one of the locals. Truck started but then died and haven't been able to start it since.

Have been reading various threads to diagnose.

A friend and my partner are doing the work. Neither are mechanics.

Did an initial visual and some of the wires going to the fuel pump were severed. Did a patch on these.

Tested power at the pump and it started.

Did the paper clip jumper test and it blew the 15 amp EFI fuse twice. What does this mean?

Wanted to check the COR relay but can't find it. I'm hoping that your picture will help me! Just to confirm, it is accessed inside the truck or via the engine compartment?

Also regarding the VAFM there is apparently a switch that controls the air flow? Where is this located? I read a thread that you can feel it by putting your hand inside the hose. Did that, but nothing?

So as you can see, need all of the help I can get This is my only vehicle and it is how I get to work. No truck no work so $$.

So I need to know what to check and where to look. Saving grace is I have a parts truck. Hoping to strip a few parts for this repair. Previous owner was an avid 4Runner guy so many upgrades done.

scootmonkey

Regarding my previous post, we figured out why the 15 amp fuse blew. We didn't have the key in the on position! Dope! Tried the paper clip jumper test again and it didn't blow the fuse, but the pump doesn't come on. It did however come on when we jumped it directly.

Any ideas here? Should I post this in a different thread?

Tayopa

G'evening monkey: first go to --> http://www.wiringdiagrams21.com/2010...wiring-diagram

Follow through. When you turn on the switch you pass power to the EFI relay which in turn passes on curent to the COR contacts which feed the fuel pump, but they are still open.

When you turn to start, you activate the COR 'pull in relay coil' which closes the contact passing power to the fuel pump.

When the engine starts and you release the start relay the COR pull in coil opens and power to keep the fuel pump running is now dependent upon the COR hold in coil, which is now held in by passing power to the coil through the closing the Air flow switch, whch closes when there is a flow of air through the the air intake hose when the engine starts. As long as the engine is running it will hold in the COR relay giving power to the fuel pump

In an emergency the COR contacts may be jumpered, B+->FP, in the relay box in the engine compartment, but remember it ia very dangerous if you have an accident, Read my posts above on this.

Don Jose de La mancha (Tayopa)

Scott Simpson

Cor isin that opening you see