When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I know you said you hear the pump working. But, make sure anyway that it is getting voltage. 12 volts or more.
I may have missed this detail in your post, did you u due the fuel line at the filter to see if there is any movement in the line?
I will check next time I go to work on it with my meter to make sure it has 12v or more. I think you have some typos in that reply. But.. I am looking at my fuel filter to visually see if there is any fuel flowing. From my FUEL TANK to my FUEL FILTER. They are only about 3 ft away from each other so it’s a small distance for the fuel to travel. (Before it even hits the electronic fuel pump) I don’t see any fuel in there moving..
Nice fuse / relay box! You'll have to give some more details on that on. Looks clean!
My questions are.
1. How can I fix this?
I would start with simple stuff like a clogged fuel line, assuming that filter is new, if not, replace it with new. Then move onto more involved like replacing the fuel pump, line routing. If it ran before in that configuration, it'll probably work again, you can just make it better. Use KISS (Keep It Simple Stupid)
2. Do I have a clogged fuel line?
Possible, the sock at the bottom of the fuel pump maybe clogged too. If you're doing a new fuel pump, replace that as well.
3. With an electric fuel pump, I don’t need a return line? Correct??
Yes, in-tank electric fuel pumps need an return line, especially if this set up is originally for fuel injection. Carbs don't need near as much fuel pressure to run as fuel injection so the excess fuel needs to return to the tank and you may need to install a pressure regulator too (carbs take 2.5 to 4 psi / fuel injection around 35 psi). You'll need a vent line as well so you don't pull a vacuum while driving or on a warm day, pressurizing the gas tank and taking the gas cap off, fuel may come out. If they're connected together, need to re-route these. Temp bypass for a vent is to take the gas cap off and the tank will vent. If you pull the gas cap off and you hear air moving in or out, vent's not working correct. I don't think these are the reasons you're not getting fuel through the filter though, they would most likely effect the engine after running awhile.
"I also may try spraying some carb cleaner on my carb too, to verify that it’s the “no fuel going to carb” being my reason for not starting."
Since you have a carb, you could replace the electric fuel system with the mechanical fuel pump pretty easy if you can't get this system to work.
Nice fuse / relay box! You'll have to give some more details on that on. Looks clean!
My questions are.
1. How can I fix this?
I would start with simple stuff like a clogged fuel line, assuming that filter is new, if not, replace it with new. Then move onto more involved like replacing the fuel pump, line routing. If it ran before in that configuration, it'll probably work again, you can just make it better. Use KISS (Keep It Simple Stupid)
2. Do I have a clogged fuel line?
Possible, the sock at the bottom of the fuel pump maybe clogged too. If you're doing a new fuel pump, replace that as well.
3. With an electric fuel pump, I don’t need a return line? Correct??
Yes, in-tank electric fuel pumps need an return line, especially if this set up is originally for fuel injection. Carbs don't need near as much fuel pressure to run as fuel injection so the excess fuel needs to return to the tank and you may need to install a pressure regulator too (carbs take 2.5 to 4 psi / fuel injection around 35 psi). You'll need a vent line as well so you don't pull a vacuum while driving or on a warm day, pressurizing the gas tank and taking the gas cap off, fuel may come out. If they're connected together, need to re-route these. Temp bypass for a vent is to take the gas cap off and the tank will vent. If you pull the gas cap off and you hear air moving in or out, vent's not working correct. I don't think these are the reasons you're not getting fuel through the filter though, they would most likely effect the engine after running awhile.
"I also may try spraying some carb cleaner on my carb too, to verify that it’s the “no fuel going to carb” being my reason for not starting."
Since you have a carb, you could replace the electric fuel system with the mechanical fuel pump pretty easy if you can't get this system to work.
Thanks for the reply.
I forgot to add some things.. I do have a fuel pressure regulator and I do have a new fuel filter. I’m not sure if the fuel pump worked before.
Responding to 3.
My question and your answer seem to be mixed up. My question was “I don’t need a return line. Correct?”
your answer says “Yes” and then says “in tank fuel pumps need a return line”. So do I need one or do I not?
There should be a fuel pump in the tank. But, my electrical fuel pump is external and mounted on the frame. (I would provide a photo but it can’t seem to upload at the moment)
I have a carb, I don’t have a fuel injected. I do hear air coming out of the gas tank when I take my cap off. Where would my return go?
I’m coming to the answer that my fuel lines are clogged. But I don’t know how to re-route my fuel lines. Where does “VENT” and my “RETURN” (if I need one) go to? Are there any thread links that you know of? Or do you have an explanation? I’m gonna keep trying to research some threads
Sorry about the confusion, you need a vent line. The vent line is one of the three lines coming out of your sending unit. It's literally just a hole in the top of your fuel tank and should run back to your charcoal or evap canister in your engine bay to trap fumes. Un-loop the return and vent lines and run a line from one of those to your evap canister, mainly to keep water from getting in the fuel system. If you're not going to use a return line, cap the other one off. Note** Can't see what's below the sending unit, so not sure what the pick up tube looks like. Is there an old factor fuel pump on there or something or just a tube with a sock on the end and the fuel gauge float??
Since you have an external fuel pump, depending on which one it is, you may not need a return line. With an external fuel pump, it should be mounted at or below the bottom of the fuel tank. Electric fuel pumps are better at pushing fuel than pulling it, so any help you can give it from gravity will make it last longer.
For you current non-fuel problem, I'd try blowing out the fuel lines with some low pressure air. Blow back to the fuel tank and see if you can hear some bubbling. Also listen to see if you can hear air escaping, I've had a metal fuel line develop a hole before, so now the pump sucks air instead of fuel. If you're not certain about the fuel pump working, check that out too. I'm not a huge fan of out of tank electric fuel pumps since they are prone to burning up faster than in-tank fuel pumps. My advise if you're going to keep that set up, carry a spare one. Just curious, why not use the mechanical fuel pump set up with a carb? It's simple and reliable for you're set up. (Assuming 22R with a Weber carb)
Sorry about the confusion, you need a vent line. The vent line is one of the three lines coming out of your sending unit. It's literally just a hole in the top of your fuel tank and should run back to your charcoal or evap canister in your engine bay to trap fumes. Un-loop the return and vent lines and run a line from one of those to your evap canister, mainly to keep water from getting in the fuel system. If you're not going to use a return line, cap the other one off. Note** Can't see what's below the sending unit, so not sure what the pick up tube looks like. Is there an old factor fuel pump on there or something or just a tube with a sock on the end and the fuel gauge float??
Since you have an external fuel pump, depending on which one it is, you may not need a return line. With an external fuel pump, it should be mounted at or below the bottom of the fuel tank. Electric fuel pumps are better at pushing fuel than pulling it, so any help you can give it from gravity will make it last longer.
For you current non-fuel problem, I'd try blowing out the fuel lines with some low pressure air. Blow back to the fuel tank and see if you can hear some bubbling. Also listen to see if you can hear air escaping, I've had a metal fuel line develop a hole before, so now the pump sucks air instead of fuel. If you're not certain about the fuel pump working, check that out too. I'm not a huge fan of out of tank electric fuel pumps since they are prone to burning up faster than in-tank fuel pumps. My advise if you're going to keep that set up, carry a spare one. Just curious, why not use the mechanical fuel pump set up with a carb? It's simple and reliable for you're set up. (Assuming 22R with a Weber carb)
Im only running electrical fuel pump because I bought it from the previous owner with one. Didn’t seem to work though (I towed the truck home) Also because I’ve read up how some people have ran into problems with mechanical fuel pumps in the past.
So I’m fine with going this route. At this moment I’m planning on dropping the tank and checking in the tank and also blowing out those lines you were talking about. That must be my problem and I hope it solves it. But that link above also talks about how there’s no fuel pump inside the tank for 22r’s w/ Weber carbs. I’m a noob w/ questions and I guess I didn’t know that? Haha.
So I guess I need to drop the tank and investigate and learn myself..
As for my return line.. I’m gonna cap it off.
and my vent line, I can just leave it uncapped and run it into atmosphere correct? I also don’t have a charcoal canister because it was previously deleted. So thats another reason why I don’t want to route my vent line. Any one else have any answers? Hopefully have some results soon. Thanks again. Aloha
Venting the fuel tank to the atmosphere will work, just won't pass emissions if you have to worry about that. I would put something on the end of the vent line, like a simple one way valve to keep water, dirt, or whatever from getting in the tank and run it higher than the tank.
If your's didn't have fuel injection to start with, it wouldn't of come with an in tank electric fuel pump, only one mounted on the side of the head on the front passenger side. I'm assuming you have a block off plate there now. If you do decide to go mechanical fuel pump, make sure the cam is still there over the timing chain that drives the pump. Easy to spot if you take the valve cover off. It's not normal to take it off because you need it as a spacer, but you never know what a previous owner did. Same with what may or may not be in your fuel tank, vehicles with 22R's didn't have electric fuel pumps, only the 22RE's, 22RET's and 22REC's. If you have the problems with carb fuel inlet conflicting the the fuel pump like that article had, maybe consider a spacer at the bottom of the carb for clearance?? I've done that with older V8's with 4 barrel carbs to give them some clearance off the intake to miss something that conflict with linkage, etc.
Did you ever get it to fire by putting spraying carb cleaner or putting gas in the top of the carb? When I was trouble shooting mine, I could get about 30 seconds of run time with putting a little gas in the throttle body. Hopefully blowing out the lines solves you're problems and you'll be wheel'n in no time!!
Hey, sorry for the late reply. But here is what I found and read abit on
Hi Koliah808, Please start a separate thread about this so as not to clutter the thread AND make it easy for future searches for problems similar to yours.
I suggest you copy essential discussion here and post on new thread.
Add the cutoff switch he warns of! Don't be dumb! Don't be me!
Originally Posted by RAD4Runner
Next only to our senses, the multi-meter is the most important electrical diagnostic tool. Spend $6 at Harbor Freight or $$$ blindly replacing parts.
Couldn't agree with you more!
Firstly Rad4Runner, thank you for your dedication on an issue that plagues so many of these trucks!
TL;DR: Replaced plunger and contacts, went from occasional start to no start. Jumpered to starter, starts Everytime. Wired up relay haphazardly, no issues and started every test. Wired up with relay in open space in engine fuse box, let the factory smoke out of multiple wires til the battery terminal melted apart breaking connection.
Fuse circuits! Install a kill in case of 30a relay welding itself permanently on as warned by Rad4Runner repeatedly!
I have a 10/90 so 91? 4Runner v6 (3vze) M/T saved from sitting in a field for 10 years.
Starter began having issues a year ago and has been getting worse so I decided 2 days ago to pull the starter and replace plunger and contacts. Kit came in so I pulled it out, realized kit was wrong but if I reused the contact bolts with new contacts it would work. Put it all together and back in, no start. Too late to keep working in friend's garage so I push start it to get home.
Come back yesterday, pull it, before cracking the solenoid open to check the plunger we run a wire to reach from solenoid to batt+, used jumper cables to ground the starter to batt-, balance the starter on upper ball joint to bolt large diameter batt+ cable to starter motor terminal and it cranks perfectly Everytime.
Great news is, that I didn't rebuild it incorrectly!
I check voltage at battery at 12.5v
Voltage at wire that plugs into starter solenoid 11.4 while cranking at ignition barrel. Only 1.1v of voltage drop is enough for our starters not to crank. Good to know! Also new springs in plunger I'm guessing require more amperage which may explain 0 starts from original wiring setup.
I recall seeing an old post about a diy version of the hotshot relay so I grab a 30a relay and with the starter in that same situation as listed above, I use ignition power to signal side of relay, ground other side of signal circuit. Batt+ to normally open relay terminal and then connect last lead from solenoid to switched power terminal. Crank with key at ignition, works 3x back to back.
I disconnect all the wires so I can run them up the fender to the fuse box where I can tuck the relay. I reinstall the starter. I hook up everything exactly the way I had it but now I have case ground at starter instead but that's about it different.
Key ignition test, kachunk at starter, no crank. Try again, starts up sounds great. Try again, cranks and starts but my buddy yells smoke! Sure enough, I pulled the key, get out and look there's smoke billowing from near my relay and at the firewall.
Ground side battery cable terminal melts the threaded post off.
All the smoke stops. We let it cool, most wires are too hot to touch. I sit down and have my first beer of the evening to help figure out schematically what just happened.
The relay had to have failed. I really wish I had read this thread and how you warn to install a kill switch to make sure what just happened to me doesn't happen.
I'll be back at it today and had planned on getting an old style ford 3 post starter solenoid to handle the amperage. Also having read your entire thread here combined with my new experience, I would like to know thought on putting a 30a automatic circuit breaker instead of a fuse on the hot side of the relay from the battery. Also may wire it in after the 80a fusible link I put in the fuse box when I did the cable upgrade from batt+ to fuse box 2+ years ago. Should guard from any potential factory smoke deletes we attempt today.
I've never looked at the diagram for the hotshot setup but I should now. Bought a 30a circuit breaker at the local APS and didn't get a chance to return to the project yet today.
I have a wiring kit for my LED headlights to be able to use the brights because of the negative side relay issue and am thinking about using the relay I just added to provide power from the normally closed terminal. I'll try to take some pics and upload once I'm done with just the starter relay wiring.
Another one saved! Employed everything I learned from this thread on a 1990 3VZE (old UHaul Box Truck) and it starts every time. It took me 30 minutes to prepare for the job and 1 hour for installation. 3VZE Starter Bypass
Good lookin' job on the heat-shrink. Did you get the crimp-able bare terminals, with the separate crimp that grips the insulated part of the wire? (OEM style)
Thanks! Yes, I used non-insulated terminals ( i dont like to crimp through the plastic insulation) and use thick heat shrink. Regarding the insulation grip, the terminals I used do not have the additional crimp for the insulation; the tooling and terminals get a little expensive for my taste. But the thick heat shrink acts as a pretty good strain relief
Another one saved! Employed everything I learned from this thread on a 1990 3VZE (old UHaul Box Truck) and it starts every time. It took me 30 minutes to prepare for the job and 1 hour for installation. 3VZE Starter Bypass
+1 on the clean work, and for sharing your experience and results.
May we know what year model truck for future reference?
I'm glad to see you're using the meltwall (FIT-300) heatshrink. That's the best for automotive applications. It keeps all the nastiness that floats around in a car, especially the engine area, out of your joins, crimp OR solder. Besides the fact that it makes a decent strain-relief.
I would watch that heatgun you use though. It's made for stripping paint, and so forth. Not electric/electronic applications. Like heat shrink. It's very easy to over heat the shrink, and damage it, eliminating it's effectiveness. You should use one that's designed for this application, like THIS ONE which is what I use for heat shrink.
I'm glad to see you're using the meltwall (FIT-300) heatshrink. That's the best for automotive applications. It keeps all the nastiness that floats around in a car, especially the engine area, out of your joins, crimp OR solder. Besides the fact that it makes a decent strain-relief.
I would watch that heatgun you use though. It's made for stripping paint, and so forth. Not electric/electronic applications. Like heat shrink. It's very easy to over heat the shrink, and damage it, eliminating it's effectiveness. You should use one that's designed for this application, like THIS ONE which is what I use for heat shrink.
Just wanted to mention this.
Pat☺
Yeah that HF heat gun is a little rough lol. ill have to look in to a new one.
07-08-2020, 08:27 PM
