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I tried to locate your response quite a while back but couldn't find it. Thank you for this information. The weather was too hot for me to be working outside so I didn't put it back together and test with current. Good thing. The NGK coil arrived the Monday after Labor Day weekend and was not the same as pictured on the website. Called both Monarch Warehouse who had me call NGK about this and was assured it was the right one. Not being a mechanic I never thought to simply check if the coil wire fit on it before installing. It didn't fit. The wire cap was too small to fit over the coil tip. I ordered another NGK U1157 thru Auto Zone to see if they sent that same one, which they did. And also the 12X from Standard Brand. The wire on it is a tight fit but at least it says for use with an external resistor on it. I installed it today and the truck did not start. Something is shorting out when turning it over as the battery gauge shows it as discharging a great deal as soon as i turn the key to start. Then it dies as it goes back to run. But I also smell something like hot wiring. So tomorrow is another day. To be continued. Will get on my phone and try to send all the photos. Thank you again for helping. There is more to the story but you really need to see the photos I have of the components along with it.
Well at least we're getting closer. One thing I didn't mention (and I should have earlier, my apologies) is now that you have a new coil, you should test for spark upon cranking. At least this will tell you if the ignition system is putting out spark to the distributor. Just take the wire from the coil to the distributor off the distributor center post, put a screwdriver in the end of the wire so it touches the terminal inside the wires' cap, touch the screwdriver shaft to some unpainted metal in the engine bay, and have someone crank the engine over. If the ignition system is working at all, you should see sparks between the screwdriver shaft & the metal. Be careful not to touch any metal when you do this. The coil can produce 30,000 to 50,000 volts and it will "bite" you if you give it a chance.
That NGK coil should have been fine for the application. The wire boots are supposed to be a very tight fit. The Standard UC12 coil I have also says "for use with an external resistor" but my GM HEI setup does not use a resistor. If the above test shows no spark or a very weak spark from the ignition system, I'm still leaning towards the ballast resistor being bad, condenser being bad, or a problem with the points. You never told me if the points you have in there were replaced with new or not. The points also have a gap spec, .018", that needs to be correct. Too big of a gap could cause the rubbing block in the distributor to not allow the points to close, which would cause the coil to not fire. Also are the ignition wires new or no?
Thank you for the positivity. Waiting for someone to be around to check the spark. In the beginning I had fuel and spark but kinda weak spark with the old coil. One new thing before it stopped running, I never used to hear an electric fuel pump when the key was on and the car was not running. In fact I thought I had a manual fuel pump. Still working on sending photos.
I never used to hear an electric fuel pump when the key was on and the car was not running.
You won't, unless the key is turned to start without the clutch pedal pushed down, and the Clutch Cancel switch (if you have one) is not pressed. OR, if you put the jumper in the fuel pump test connector, and turn on the key, not to start, just to On, you could hear the fuel pump.
This is the purpose of the COR. It makes sure the fuel pump doesn't run with the key on, unless it's turned to Start, with the clutch engaged, when you start the engine, or there is air flowing through the AFM, like after it begins running, opening it's vane.
This ensures that in the event of an accident, where the engine shuts off with the key still on, there's no pressure, or fuel flow, in the fuel system. Prevents leaks, or massive squirts of fuel, out onto the ground, rescue workers, you, etc, hopefully preventing fires. Kinda a really good idea, IMHO.
My Experience With This Thread...Positive and How To Simplify
Bottom Line- If you have an old Toyo Truck...don't try to figure out what's wrong. Just start with replacing
everything that should be replaced.It's going to go bad at some point. And nothing costs much.
This thread has a lot (and I mean a lot!) of detail in it. Very appreciated. Thank you 13th Sword.
What helped me-
1) I had to slow myself down...read through it...and create my own checklist
2) I had to learn to use a multimeter well. Measurements can be thrown off if you don't understand what you're measuring
3) Trust my experience. Some of the hints and instructions weren't clear to me. So instead of trying to "figure out what he meant"
I just used my common sense and experience.."What shoud work here"
Making It Easier
1) When ordering a new Bosch style plug..make sure you order the whole package...plug with the wires. There so inexpensive
you can buy several on line for the price you would pay locally.
2) When cutting wires for the new plug...make them 4 to 6" It gets tight in there.
3) Measure the Volts coming out of the old harness with key on. It pointed to a problem with fuel pump. And to the ignition switch itself.
4) I had a bad wire running from resistor area to pump.
1) I created a Y harness for the resistor end to plug into the power side. (Looking back, I didn't need to go through that trouble. Could have
just spliced into the power line.0)
2) Ran a wire back to the pump...and instead of replacing it just spliced it in on both ends
Last edited by John Shoemaker; Sep 30, 2020 at 07:50 AM.
Thank you for the positivity. Waiting for someone to be around to check the spark. In the beginning I had fuel and spark but kinda weak spark with the old coil. One new thing before it stopped running, I never used to hear an electric fuel pump when the key was on and the car was not running. In fact I thought I had a manual fuel pump. Still working on sending photos.
No problem. On Toyotas you generally won't hear the electric fuel pump running, as they tend to run quiet. I had to take my gas cap off & listen at the fuel fill pipe to even hear anything with my new pump, and I could barely hear it even that way.
Just a point of reference for anyone else who may not know - There were some 20R engines made that used a mechanical fuel pump, but that pump was mounted to the cylinder head, on the front passenger side, and is easy to spot under the hood. My research indicates that they were used on 1980 & 1981 pickups with the 20R. in 1982 Toyota switched to the 22R engine and those with a carb mostly came with a mechanical fuel pump. I have seen a few carb'ed 22R models that have the electric fuel pump system, but do not know if this was stock factory or not. Later owners may have replaced the fuel injection with a carb for who know what reason(s).
You won't, unless the key is turned to start without the clutch pedal pushed down, and the Clutch Cancel switch (if you have one) is not pressed. OR, if you put the jumper in the fuel pump test connector, and turn on the key, not to start, just to On, you could hear the fuel pump.
This is the purpose of the COR. It makes sure the fuel pump doesn't run with the key on, unless it's turned to Start, with the clutch engaged, when you start the engine, or there is air flowing through the AFM, like after it begins running, opening it's vane.
This ensures that in the event of an accident, where the engine shuts off with the key still on, there's no pressure, or fuel flow, in the fuel system. Prevents leaks, or massive squirts of fuel, out onto the ground, rescue workers, you, etc, hopefully preventing fires. Kinda a really good idea, IMHO.
Is this a small help?
Pat☺
SLV is working on a 1977 RV model of the truck and it has a 20R with a carb, so there is no fuel pump test connector or AFM (Air Flow Meter). To the best of my knowledge those are only found on 22RE Fuel Injected engines. You are correct about the COR though; it works the same way for either type of engine. The only difference being that on carb'ed models of the 20R or the 22R, the signal going to the COR is from the Oil Pressure Sender Switch, while the 22 RE EFI models use the signal from the AFM
Bottom Line- If you have an old Toyo Truck...don't try to figure out what's wrong. Just start with replacing
everything that should be replaced.It's going to go bad at some point. And nothing costs much.
This thread has a lot (and I mean a lot!) of detail in it. Very appreciated. Thank you 13th Sword.
What helped me-
1) I had to slow myself down...read through it...and create my own checklist
2) I had to learn to use a multimeter well. Measurements can be thrown off if you don't understand what you're measuring
3) Trust my experience. Some of the hints and instructions weren't clear to me. So instead of trying to "figure out what he meant"
I just used my common sense and experience.."What shoud work here"
Making It Easier
1) When ordering a new Bosch style plug..make sure you order the whole package...plug with the wires. There so inexpensive
you can buy several on line for the price you would pay locally.
2) When cutting wires for the new plug...make them 4 to 6" It gets tight in there.
3) Measure the Volts coming out of the old harness with key on. It pointed to a problem with fuel pump. And to the ignition switch itself.
4) I had a bad wire running from resistor area to pump.
1) I created a Y harness for the resistor end to plug into the power side.
2) Ran a wire back to the pump...and instead of replacing it just spliced it in on both ends
You're most welcome and thank you for the kind words. I glad that what info I could give helped you get it done and I'll try to be more clear and simple in the future. There is always room for improvement.
Wiring is extremely basic. It's just a Toyota truck. I have some diagrams. If I can find easily I'll put up.
If ou are handy, you can just follow the wires.
Or look for color codes on either end to match up...send some volts through to test.
For replacing the pump, I didn't want to drop the tank.
So I cut a circular hole in the floor above the tank for access...and finished it with a deck plate for boats.
Having a hard time figuring out this website let alone my 1977 Chinook wiring. Some of these threads are a little old. Like the Chinook. Is anybody out there that can help still?
Good Morning...If you are still looking for a wiring diagram and other help on working on the Toyo...
1) Haynes Manual...Toyota Hi-Lux Pick Up 1969-1978 ( I have a '77)
Has several pages of wiring diagrams in the back.
2) Have you seen "How to keep your Toyota Pickup Alive" by Larry Owens. 1975-1987 Models.
Very,very thorough (400 pages) Step By Step. Practical and useful.
If you are allergic to spending money, there are PDF copies online...including one of the Chinook owners sites.
The original copies are around $100.00 Well worth it for me. The PDF copies are cumbersome to search
through. But you can print out the pages you need.
I have found a number of specific manuals hiding out there.
3) Some of the Toyota Factory shop manuals. The trick there is
they had about five of them...one for each part of the truck. IE Body, Electric.
4) Found Chinook specific manuals...in of all places, Etsy.
I wonder how much experience you have working on cars and trucks?
I say that because if you don't have much experience...have a bureacratic mind..
and need an Exact Step By Step source...or can't handle too many details at once
you might get very frustrated.
1) None of these are totally complete. What I mean is, all the answers are
not in one place. Different ones have different strengths. Many leave out
steps that are important assuming you have a certain level of knowledge
and experience.
2) Diagnosis and Fixing are two different stages. Some books help you
diagnose. Some are more specific to Fixing.
If you want to save yourself lots of frustration ...don't limit yourself when searching to just Toyota or Chinook.
I found that when you get to specific sites (like this one) that there are many
"half experts". So you can be better off going to a site like 2carpros for real
answers about general problem...like replacing fule pump...which are universal.
And get more correct info than so many guessers or hacks. They mean well Im sure
But info can be off.
The labels for the pictures did not go thru. First is taking apart the coil assembly. 2 is the condenser that sits next to the coil 3 and 4 the fuel pump relay 5 what I am calling the igniter sitting on top of the coil bracket. You can also see the blue separator for the 12 V camper system. It is a Dodge part. and the last one shows the difference in size of the distributor wire connection to the coil the original Nippondenso on the left and the NGK on the right. The wire boot would not go on. Plus it does not say for use with an external resistor. It is not the one that is shown on their website for that number. The U12XBlue Streak from Standard Brand is a very tight fit. I had to pull the connector end out of the cap to insure it was connected properly. .And a side note to proper fitting I bought a new rotor for the distributor at Advanced Auto which was same exact
Duralast that I have made in Mexico and it did not fit! It was too tall and so tight I was really careful pulling it back off again...I certainly appreciate all the input i have received. I have more photos to post.. I have to send them to my daughter to post and i will do that later today, 4 hour time difference between us. So I have spark with the new coil. The points which I did have replaced once look brand new. There was a little bit of dirt in the grease at the rubbing bar but slid a cardboard business card thru and it cleaned up. I need feeler gauges tho to be exact. I am going to go back thru with my testing. Make sure I have my settings right for what I am testing. I have a little experience in car repair replaced a starter and power steering pump in a jeep. Did the breakdown to replace a timing chain in a Courier to cut repair cost. .But none in electrical. My one advantage is that I realize when something is not right and get it taken care of so I am not broken down on the road. Learned thanks to Walmart auto centers how to change my own oil when one of their attendants didn't put on a new filter. Which was a good thing because now my cars last til 300K miles. I have all the orignal maintenance manuals for this 77 Chinook so if anyone needs me to look something up I can. I had to take time out to get online and search for another vehicle. 4x4 for under $7K within 75 miles of Denver. Pickings are pretty slim right now. Base Toyota pickups especially. To be continued. Gotta get back under the hood again and get down to specifics.
@13Swords Guess what? My fuel pump is out again. I have installed a fuel regular and noticed the pump fluctuating between 0 - 3.5 psi before it died. From the last time we had this discussion, I connected a constant current of 12V to the BY wire at the relay end in the car. Did a visual inspection of the fuses today and all are good. Tomorrow I will be getting under the truck to test the voltage at the tank connector. I have another in tank pump on hand so I will be replacing it with that one if the voltage at the tank reads well. I have done this job so many times that I got it down to a 2hr job. What I will be doing this time is scrubbing the rails where the tank meets the frame with a wire brush I'm guessing that is the tank ground. If the reading at the tank end is not good I will be getting under the truck and putting hands and meter probes on the wires. I have to start looking for an external pump option, this is the 3rd time I will be replacing the fuel pump. It was last year when we did this dance and the warranty on the pump is one year and I guess that's how long they last. I was looking at this pump I can install it in the engine bay next to the fuel regulator on the passenger side. I'm planning on removing the smog pump and all its vacuum stuff to make room for the fuel pump.
@John Shoemaker That is my plan to just replace what no longer works. Problem I'm having is nothing is made any more and no one knows or wants to work on this truck.
I know why your fuel pump is out again. You said "I connected a constant current of 12V to the BY wire at the relay end". Doing this, you are bypassing the fuel pump resistor. The stock pump is not designed to run on constant 12 volt battery power. That burns them out in short order, like you have just experienced. The way Toyota designed the fuel pump circuit, the fuel pump only receives full battery power when the key is in the start position and there is no oil pressure. Once either full oil pressure is achieved (either by cranking the engine or engine start), the "start" side of the relay opens and shunts voltage back to the "run" side. I posted the diagram for the fuel pump circuit previously in this post, but here it is again:
Note the fuel pump resistor in the circuit. The BY (Black with Yellow stripe) wire comes from the ignition switch "run" position. That's why the diagram is marked showing the BY wire from the resistor going to a terminal in the relay marked "R" for "run". This resistor is rated at 1.4 Ohms and is meant to drop the voltage to the fuel pump with the key in the "run" position. Note that there is another wire BW (Black with White stripe) that comes directly from the ignition switch "start" position.
The reason for the fuel pump resistor is fuel pump longevity and quiet operation. The pumps are NOT designed to run constantly on battery voltage, which is actually 13.8 volts, The resistor drops that voltage to the pump to something near 9.85 volts. The math on this is simple. 13.8 volts (battery) divided by 1.4 Ohms = 9.857 volts. That's about a 30% difference in voltage, so basically bypassing the resistor like you did, you've been "overdriving" the pump by that much. The electric motor in the pump wasn't designed to handle that, so it wears/burns out quickly. So you NEED that resistor in the circuit or you're just going to burn out the next new pump again in about the same time frame as the last one.
You can test the voltage at the tank connector, with the key turned on to run, but without the truck actually running, you are only going to read full battery voltage, with the way you have it wired up now. I'm not at all sure why you decided to wire full battery voltage to the relay. Are you still using the stock ignition switch or no? If you are, you should already have full battery voltage at the "inlet" at the fuel pump resistor, with the key in either the "start" or "run" position. Again, I posted pics of the resistor before but will do so again. It is located underhood, passenger side, top of the wheelwell.
Note the green connector. You can take this apart and measure the resistance of the resistor. Cold, it should be 1.4 Ohms. !.5 or higher and you need another resistor. I have info on a mod for this that isn't too hard, and I also posted that info previously.
Also, with that connector apart & the key in the "run" position, you can use a volt meter to see what voltage is getting to the resistor from the ignition switch.
Any specific questions or anything you don't understand here let me know, and I'll try to explain it.
You are correct, the fuel tank does ground to the frame, and a good ground connection is always critical. The stock in-tank fuel pumps, as long as they are quality, will last much longer than the 1 year warranty. Mine is a WVE/Wells-Airtex brand (part # E8188) and has been working fine for over 3 years now with no issues.
The aftermarket fuel pump you linked to is overkill. It's rated at 110 gallons per hour, which is about 4 times more than you need; a 30 GPH pump would be plenty. This one is pretty commonly used: https://www.holley.com/products/fuel...umps/parts/42S
I don't remember if you are running a Weber carb or not, but the fuel pressure on that one is perfect for the Weber. I also recommend a fuel pressure regulator setting for the Weber at 2.5 PSI. They don't like much beyond that or they like to flood.
If you're still using the stock carb, this one would work; it's got the proper PSI spec: https://www.holley.com/products/fuel...s/parts/12-427
You should never mount an electric fuel pump in your engine bay, for several reasons. 1st, underhood heat, which can easily exceed 200 degrees F, can shorten it's life. Heat kills electric motors; that's why most pumps are mounted inside the tank, the gas sloshing on them keeps them cool. It's also a fire hazard to mount an electric pump in the engine bay. More importantly, electric fuel pumps work best when placed as close to the fuel tank as possible. This is because they are better at "pushing" as opposed to "drawing". Mechanical pumps are just the opposite. The electric pump is going to have to work harder to draw fuel all the way from the tank to the engine, so it's always best to mount it as near to the tank as you can. Commonly on these trucks, when people go to an aftermarket fuel pump, they mount them on the frame just ahead of the tank. So no need to remove all that stuff, unless you're going to do a complete de-smog, which is a whole other subject.
I get the parts shortage, but I have been able to overcome most of this. Again, anything specific just ask, I have work-arounds for most everything, and they work well.
@13Swords This time it was a false alarm the wire connector to the tank wiggled out. You are correct about the resistor I was by passing it straight from the battery. The last time the pump went out I was doing all the work on the street and needed to finish so I rushed the process. I have ordered a resistor and will be installing it when it arrives. I'm running a Weber carb with a fuel regulator and I have the pressure set to 3psi.
Understood, and thank goodness it wasn't anything more major. Good on the resistor; that will keep your fuel pump alive for a lot longer. I also had a fuel "incident" this week. After more than 3 years later of the fuel system being completely fixed, I started to smell raw gas coming from the front of the truck while driving. Of course this HAS to happen away from home & proper tools. Pulled over and had a look, and found gas all over the passenger side of the carb, dripping. From the looks of the location of the leak, I thought maybe one or more bowl cover screws had come loose. Grabbed a multi-tool I keep in the glove box and tried tightening all the screws. Found three of them a bit loose. All the lines seemed dry so didn't suspect those. Started it up & went straight home, still smelling the gas, hoping I didn't become a car-b-q. Got home, looked again while it was still running. There was tiny jet of liquid gas shooting out between the metal inlet fitting & the carb! The bolt that holds the fitting to the carb had somehow "backed out" & gotten loose. One 17mm box wrench & 10 seconds later, no leak. Guess who's gonna start looking for a cheap set of wrenches to carry in the truck from now on?
I'm glad you didn't have an inadvertent ignition problem.
Thanks for letting us know what it was. That'll be a great help to someone, I'm certain.
I carry a complete set of tools in both my trucks. Crescent wrenches, a socket set, a few different size screw drives, both phillips and standard, AND spare parts. Since I give them a tune up every spring, I always have a set of spares handy. You know, plugs and wires, distributor cap and rotor, radiator hoses, belts, etc. Handy if anything fails on the road. I put the stuff I pull off in the storage, and throw away the previous year's parts. All my spares are thus less than 1 year old. Comes in handy on occaision.
Have fun now that you're less likely to become a car-b-q!
Pat☺
I see this post is 15 months old. I have a 77 Celica that needs a resistor. has 2 eyelets that will have to be soldered. I just ordered the resistor from Mouser and it doesn't look like the one pictured in the post.. Mine that arrived today looks like this: I will try to post a pic. This one has HS10 1R5 F printed on it. It is 10W 1.5 OHM. The pic in the original post is threaded with a nut and lock washer . Is this the correct one? Thanks for your input.
The resistor you received will work just fine and is the correct one. It is obviously an aluminum-cased power resistor rated at 10 watts, which was the original wattage spec. Original Ohm spec was 1.4 but a 1.5 Ohm resistor will not cause you any issues.
The type/style of termination (terminals) really doesn't matter, as long as you can securely install the resistor into the circuit with good contact. In fact the "eyelet" style of resistor you are showing in your pic will make soldering it to the existing wires easier.
For clarity and for anyone else reading this, the original picture I posted of the Ohmite HS10 1R5 F resistor is a catalog "stock" picture from Mouser's product listing here: https://www.mouser.com/ProductDetail...WgobfMBw%3D%3D
If you look at the specs for the part, it does specify that it does indeed have "solder lugs" on it.
Last edited by 13Swords; Apr 1, 2021 at 04:23 AM.
Reason: spelling
Sep 28, 2020 | 07:18 PM
Pulled over and had a look, and found gas all over the passenger side of the carb, dripping. From the looks of the location of the leak, I thought maybe one or more bowl cover screws had come loose. Grabbed a multi-tool I keep in the glove box and tried tightening all the screws. Found three of them a bit loose. All the lines seemed dry so didn't suspect those. Started it up & went straight home, still smelling the gas, hoping I didn't become a car-b-q. Got home, looked again while it was still running. There was tiny jet of liquid gas shooting out between the metal inlet fitting & the carb! The bolt that holds the fitting to the carb had somehow "backed out" & gotten loose. One 17mm box wrench & 10 seconds later, no leak. Guess who's gonna start looking for a cheap set of wrenches to carry in the truck from now on? 
