all that for nothing

[Wayne]

My recent trials and travails of diagnosing and ultimately deciding I needed to replace my fuel pump are well documented here. Well yesterday I spent hours getting the damn tank out. I got the effing pump out and hooked it up to a fused cigaratte lighter cord and it runs fine. I can't effing believe I went through dropping my tank just for this. I hooked 12v to it when it was in place, and heard nothing. But there's no way I could have heard this thing run in the tank, I could barely hear it whispering even in my lap.

back to square one.

 

[mikebontoft]

you could have also jarred the commutators into operation again just by removing the pump. It can also have flow and no pressure.

What was your diagnosis process? You say it's well documented, where's the link?

 

[KidVermicious]

I agree with Mike, the act of taking the pump out could have knocked internal connections back into place momentarily. Don't put it back in, because if you're sure it wasn't working when you gave it 12 volts right at it's connector, then it won't stay working.

I think you should still replace it.

 

[Wayne]

I banged on the pump when it was in the tank much harder than any jarring it received since then. While I think thats possible, I don't think its likely. I don't have time to look up the links just check the three threads I've posted on recently. The eseential point that was never addressed in my diagnosis process is why wasn't I getting 12v to the blue/orange wire which feeds the pump, even when someone was cranking the engine, and why did it seem the fuel pump(circuit opening) relay wasn't energizing? This points to something other than a dead fuel pump, IMO, which is why I procrastinated a month before finally dropping the tank. But I'm not very good at electrical testing so I saw no other option for further testing. But now I will be tracing the wires back to the relay. I had the circuit opening relay tested and its good.

 

[EatonKyleH]

I read through your diag in your previous thread. Some questions it left me with....

Is there 12 volts from the 20 amp EFI fuse to EFI relay?
Did you jump the relay if there was?
Did you then have 12 volts to the circuit opening relay?
Did you jump the relay if there was?

I don't know if you know what I'm talking about or how to check these things but these are just steps that would to involved in diagnosing why there is no power to the pump and what the cause of that is.

I can assist you with more detail in testing procedures and what the outcomes mean if you need.

 

[TheDurk]

I read through your diag in your previous thread. Some questions it left me with....

Is there 12 volts from the 20 amp EFI fuse to EFI relay?
Did you jump the relay if there was?
Did you then have 12 volts to the circuit opening relay?
Did you jump the relay if there was?

I don't know if you know what I'm talking about or how to check these things but these are just steps that would to involved in diagnosing why there is no power to the pump and what the cause of that is.

I can assist you with more detail in testing procedures and what the outcomes mean if you need.

You must be new at this internet thing. Analytical troubleshooting is too much work. Please keep your posts to random guesses or your stories of fixes to unrelated problems. You'll get the hang of it.

 

[Wayne]

I'm not good at electrical problems or diagnosis, as I disclaimed in at least one of those threads. No, I did not do those tests and no I don't really understand all of them. I did understand that not getting 12v to the pump when the engine was cranking was a sign something other than pump might be involved.
And yes, I would appreciate instructions on how to do those tests. I can (probably) do it if somoene leads me through step by step in detail. All I have is an analog multitester though, and an incomplete understanding of how to use it.

The EFI relay clicks with the ignition on, so I think that answers your first question. I think the next question would be a good place to start.

 

[the great him]

I read through your diag in your previous thread. Some questions it left me with....

Is there 12 volts from the 20 amp EFI fuse to EFI relay?
Did you jump the relay if there was?
Did you then have 12 volts to the circuit opening relay?
Did you jump the relay if there was?

I don't know if you know what I'm talking about or how to check these things but these are just steps that would to involved in diagnosing why there is no power to the pump and what the cause of that is.

I can assist you with more detail in testing procedures and what the outcomes mean if you need.

you keep posting stuff like this and you will soon make us all look like fools! this requires actual work and is much too strenuous for 80% of us, please refer to [MENTION=10169]TheDurk[/MENTION] 's post above

 

[A.Wilson013]

I read through your diag in your previous thread. Some questions it left me with....

Is there 12 volts from the 20 amp EFI fuse to EFI relay? Disregard that it is clicking. Get out your multimeter and check it.
Did you jump the relay if there was? If it has 12v, do a quick google search of how to jump a relay. It's easy. If it doesn't, your issue is before that. I am not a mechanic, and if your issue is before the relay I don't know... Bad fuse? I am sure you checked that. I imagine if it's clicking you're getting 12v though.

Did you then have 12 volts to the circuit opening relay? Now with the EFI relayed jumped, use your multimeter to check the power here. Don't have 12 volts? I'd say your EFI relay is toast.
Did you jump the relay if there was? Now with this jumped as well, is the pump working? If not, I'd say the circuit opening relay is your culprit.

I don't know if you know what I'm talking about or how to check these things but these are just steps that would to involved in diagnosing why there is no power to the pump and what the cause of that is.

I can assist you with more detail in testing procedures and what the outcomes mean if you need.

Hope my points in red help you, OP.

Kyle, please correct me if I am mistaken. I am a parts replacer at best.

 

[Wayne]

Just to be clear, I brought my efi and circuit opening relay in and had them plugged into a tester. Both tested fine, which confirmed my "click" tests. The circuit opening relay does not seem to click unless I switch it with the EFI relay. So I suspect it is not getting powered. I can do the jump test tomorrow

 

[EatonKyleH]

You must be new at this internet thing. Analytical troubleshooting is too much work. Please keep your posts to random guesses or your stories of fixes to unrelated problems. You'll get the hang of it.

Ahh screw it then. Just replace the alternator they go bad all the time I've heard. My sisters boyfriends cousin had the same problem.

 

[EatonKyleH]

you keep posting stuff like this and you will soon make us all look like fools! this requires actual work and is much too strenuous for 80% of us, please refer to [MENTION=10169]TheDurk[/MENTION] 's post above

Lol I honestly have no intentions to make anyone feel foolish or to show boat and I hope my posts don't give off that kinda vibe.

 

[BrianSD_42]

Lol I honestly have no intentions to make anyone feel foolish or to show boat and I hope my posts don't give off that kinda vibe.

It's just that there are so many posts where people just start pulling parts without real analytical troubleshooting. Actual logic is very refreshing.

 

[EatonKyleH]

Hope my points in red help you, OP.

Kyle, please correct me if I am mistaken. I am a parts replacer at best.

Right on man, you could really go straight to the circuit opening relay to test for power if the Efi relay is clicking. If it has no power then there is a problem between the Efi and circuit opening relay. If it has power but does not click the control side/relay grounding side circuit has a problem. Jumping the relay eliminates the relay and the circuit that grounds it. I'd probably leave the fuel tank out with the pump connected while testing until power is restored and you can hear it run on the vehicles own circuit since already there.

 

[TheDurk]

Lol I honestly have no intentions to make anyone feel foolish or to show boat and I hope my posts don't give off that kinda vibe.

My comment was my backass way of showing sincere admiration and no criticism of your posts or their tone was involved. I am always trying to get people to troubleshoot rather than just swap parts on a guess. I WAS trying to make gentle fun of some things that go on here, but not the OP or anyone specifically in this thread.

 

[Wayne]

How do I know which terminals to jump? The relays aren't marked. I can see which one is blue/orange on the circuit opening relay (that is the power to the pump) but I don't know which one to jump it TO, and I can't see any wire colors on the relay box under the hood. Remember I'm a self-admitted electrical moron.

 

[EatonKyleH]

How do I know which terminals to jump? The relays aren't marked. I can see which one is blue/orange on the circuit opening relay (that is the power to the pump) but I don't know which one to jump it TO, and I can't see any wire colors on the relay box under the hood. Remember I'm a self-admitted electrical moron.

No problem man and I forgot these relays don't have the pins labeled lol so I ran out to my runner to snap a few pics for a better explanation.

So here is our style of relay used for EFI, circuit opening, and well... many other things like the tail light relay, power outlet relay, and so on. (my hands don't get much cleaner than that)



When the relay is operated it completes the circuit over the 2 copper colored pins. So to jump it we will complete the circuit with a wire, paper clip, etc.

I did this on my tail light relay to verify I had it right before continuing. I'd recommend you do the same. With the key on turn your lights on and remove the tail light relay and verify the taillights went off. Jump it as shown below and check to see if they are now back on. If they are (and should be) you have successfully jumped the type of relay also used on your fuel pump circuit and are ready to do just that.



If you suspect a relay to be bad you can swap it with one from another circuit that uses the same relay like the tail light relay previously mentioned. These relays are the same down to the part number. So you can swap them and if all of a sudden the fuel pump will run but those taillights wont come on... there is your bad relay (follow me?).

Now if the fuel pump runs after you jump either the efi of circuit opening relay it doesn't mean that the relay itself is bad because jumping a relay is bypassing the circuit that controls its on/off ground side as well as the relay. We will know that the control side is the problem area if the pump runs when you jumped either relay but does not when swapped with a known good relay from your taillights/etc.

Before I keep rambling on let me know what you find. Also you will be able to check power on the piece of wire in the relay with your DMM or test light. If the pump doesn't run let me know if you have power to either relay.

Good luck man and hope this helps.
-Kyle

 

[EatonKyleH]

Lol. I think I might do a little 3rd gen specific electrical diag tips write up.

Would anyone be interested in that? Or diag tips for other problems? Noises, a particular trouble code, etc?

If anyone is interested I'd be glad too I just don't want to waste my time if no one is interested.

suggestions?

 

[LittleCaesar]

What a nice concise but extremely helpful write-up Kyle. I, for one, are anything but electrical savvy, but have a couple of paper clips used to complete circuits testing AC circuits, etc. on other autos.

If you want to take a little time, I think it would be good for all here and the powers that be could make it a DIY sticky.

 

[EatonKyleH]

What a nice concise but extremely helpful write-up Kyle. I, for one, are anything but electrical savvy, but have a couple of paper clips used to complete circuits testing AC circuits, etc. on other autos.

If you want to take a little time, I think it would be good for all here and the powers that be could make it a DIY sticky.

Thanks man, lol the paper clip is an extremely powerful electrical diagnostic tool and can be used in a pinch to get home or to bypass a failed circuit. I've helped a few friends over the years get their cars started, their lights back on, etc to make it home or to my shop this way. They always find it funny when I grab a paper clip or ask a girl for one of her hair pins so I can start her car with it. Feels like some silly party trick sometimes but understanding electrical circuits can open up a lot of possibilities when it counts.

I'll work on a little 3rd gen electrical diagnostic guide. Maybe include basic circuit testing and testing common sensors and components specifically used on the 3.4L 3rd gen 4Runner. I think keeping it gen specific would be the only way I could keep component and circuit testing simplified enough. Also it makes pictures a lot easier since I own one. I do all makes and models at work including hybrids so the 3rd gen stuff is easier for me to keep in layman terms.

I really like electrical and its probably one of my stronger diagnostic areas. So this write up would be kinda fun for me. Also kinda why I tend to respond to help needed with electrical issues.

Sometimes it gets nuts though: (Show off alert...SORRY! but a little about my background)

A little sample of my normal electrical show off life although not a 4Runner....
figured some might find it interesting.

Last week:
(repairing circuitry inside of the high voltage battery pack of a Ford Escape Hybrid)

Throwing up the horns and yelling "HIGH VOLTAGE!" because I'm a nerd. (wearing hybrid service gloves so I don't kill myself)



I find it funny that these packs for the most part look like a bunch of old D cell batteries in rows..... Man I could power my boom box for the next decade on this thing!



A few years ago I was building extended range plug in hybrids out of the older Prius when there was tax credits for it.

I've also built several bizarre electric and bio fuel vehicles for New Belgium Brewing (a huge client of ours). They pay well and free beer is a plus in my book.

I honestly don't really care for hybrids but as my career progressed I found advanced electrical and driveability diagnostics is where the money is and I like money a whole lot more than cars lol.

apparently it is now known I like electrical diagnostics and repairs. Might have to go underground now all Snowden like.

I'll hopefully have something of a write up to share and get input on for the 3rd gen stuff in the near future.