Jumped the fuel pump via diagnostics ..nothin
Mar 26, 2018 | 06:58 AM
#1
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Jumped the fuel pump via diagnostics ..nothin
so I can’t start my truck. I’ve done some reading and jumped the two ports in the diagnostics port, turned the key to on and gas tank is silent. Then I cracked the cold start injector and tried turning it over. Dry as a bone. Would fuel filter be next or pump?
Mar 26, 2018 | 07:35 AM
#2
Not a bad idea to check filter. But would check power to pump at pump plug. You want the full voltage. So multimeter not a test light. Could be fuel pump relay. Or a broken wire. I had a broken wire in harness to pump. Had like 8v going to pump. Took me a bit more research to figure 8v is not enough to run pump.
Mar 26, 2018 | 08:49 AM
#4
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Before you start digging out the harness at the fuel pump, do some simple remote testing. With key-off, you should get less than 10 ohms to ground on the FP connector. If the resistance is much higher, you have an open (broken wire). With key-on, test VOLTAGE to ground at B+. It should be about 12.6v. if a little lower, your battery is probably discharged. A lot lower points in the direction of the EFI relay, fuses, ignition switch ...
muddpig had a high-resistance connection to the fuel pump, which is hard to detect remotely. At the fuel pump with key-on (and jumper in), you should get at least 12v at the pump (whether or not the pump is running). If it drops to less than 10v, the pump may not run, and you have a bad connection somewhere. If it holds at 12v, your pump is probably toast (and you would have gotten very high resistance to ground from FP).
DON'T "crack" the fuel line anywhere (oh -- too late!) Whenever you open a fuel line connection, you must replace the two crush washers. Cheaper than dirt, but only from the dealer. Instead, just pull the fuel return line from the FPR. That's a low-pressure connection, so you can just put it back on with the clamp.
muddpig had a high-resistance connection to the fuel pump, which is hard to detect remotely. At the fuel pump with key-on (and jumper in), you should get at least 12v at the pump (whether or not the pump is running). If it drops to less than 10v, the pump may not run, and you have a bad connection somewhere. If it holds at 12v, your pump is probably toast (and you would have gotten very high resistance to ground from FP).
DON'T "crack" the fuel line anywhere (oh -- too late!) Whenever you open a fuel line connection, you must replace the two crush washers. Cheaper than dirt, but only from the dealer. Instead, just pull the fuel return line from the FPR. That's a low-pressure connection, so you can just put it back on with the clamp.
Mar 26, 2018 | 01:22 PM
#5
Before you start digging out the harness at the fuel pump, do some simple remote testing. With key-off, you should get less than 10 ohms to ground on the FP connector. If the resistance is much higher, you have an open (broken wire). With key-on, test VOLTAGE to ground at B+. It should be about 12.6v. if a little lower, your battery is probably discharged. A lot lower points in the direction of the EFI relay, fuses, ignition switch ...
muddpig had a high-resistance connection to the fuel pump, which is hard to detect remotely. At the fuel pump with key-on (and jumper in), you should get at least 12v at the pump (whether or not the pump is running). If it drops to less than 10v, the pump may not run, and you have a bad connection somewhere. If it holds at 12v, your pump is probably toast (and you would have gotten very high resistance to ground from FP).
DON'T "crack" the fuel line anywhere (oh -- too late!) Whenever you open a fuel line connection, you must replace the two crush washers. Cheaper than dirt, but only from the dealer. Instead, just pull the fuel return line from the FPR. That's a low-pressure connection, so you can just put it back on with the clamp.
muddpig had a high-resistance connection to the fuel pump, which is hard to detect remotely. At the fuel pump with key-on (and jumper in), you should get at least 12v at the pump (whether or not the pump is running). If it drops to less than 10v, the pump may not run, and you have a bad connection somewhere. If it holds at 12v, your pump is probably toast (and you would have gotten very high resistance to ground from FP).
DON'T "crack" the fuel line anywhere (oh -- too late!) Whenever you open a fuel line connection, you must replace the two crush washers. Cheaper than dirt, but only from the dealer. Instead, just pull the fuel return line from the FPR. That's a low-pressure connection, so you can just put it back on with the clamp.
Mar 26, 2018 | 05:02 PM
#7
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Oh and if it helps, as I had the air box separated, my wife was trying to start the truck as I was in the engine, I could feel the flap in the air box lid operating. Don’t know if this eliminates any source of issues for fuel pump
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Mar 26, 2018 | 05:31 PM
#9
I found a sensor pump on amazon. Most around here have learned to stay with Toyota on certain parts. And if you don’t want Toyota prices go to the company that makes it for Toyota. I would work through diagnostics first. Been there and done that. Would’ve saved money.
Mar 26, 2018 | 05:35 PM
#10
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I’m gonna try, I’m utterly confused and my brain goes in a million different dir diagnosis crap like this. How I have made it to 34 I don’t know.
so as of now, it cranks and I have air door flapper movement haha.
jumped fp and b in diagnostic box and heard no pump turning on, whining, pumping, moaning or groaning. Fuses in kick panel and fuse box under hood are all good. What is my second step?
so as of now, it cranks and I have air door flapper movement haha.
jumped fp and b in diagnostic box and heard no pump turning on, whining, pumping, moaning or groaning. Fuses in kick panel and fuse box under hood are all good. What is my second step?
Mar 26, 2018 | 06:01 PM
#11
Is there a class ckicking sound by passenger kick panel when key is turned? It’s the fuel relay. Mine was hard to hear but worked fine. I went ahead and cleaned contacts.
I even hotwired fuel pump to battery in my quest to figure my no fuel problem out. Not the preferred method but a method.
Stupid bring up now after getting into so far from the basics. But how’s fuel filter??
I even hotwired fuel pump to battery in my quest to figure my no fuel problem out. Not the preferred method but a method.
Stupid bring up now after getting into so far from the basics. But how’s fuel filter??
Mar 26, 2018 | 06:02 PM
#12
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From: San Francisco East Bay
You are pretty sure your fuel pump is not running. It is electrical. This is an electrical problem. If electrical isn't your skill area, there's no shame in bringing it to someone who does this for a living.
What you DON'T want to do is start replacing parts (like some giant Lego set) because "some dude" told you to get a fancy fuel pump. You will go bankrupt long before you solve your problem that way.
But everyone has to start somewhere, and electrical isn't Rocket Science (well, actually, it is. But don't worry about that!) If you don't have a multimeter, getting one is the FIRST thing you have to do. No excuse not to have one. https://www.harborfreight.com/7-func...ter-98025.html
Then start with the tests I described earlier.
What you DON'T want to do is start replacing parts (like some giant Lego set) because "some dude" told you to get a fancy fuel pump. You will go bankrupt long before you solve your problem that way.
But everyone has to start somewhere, and electrical isn't Rocket Science (well, actually, it is. But don't worry about that!) If you don't have a multimeter, getting one is the FIRST thing you have to do. No excuse not to have one. https://www.harborfreight.com/7-func...ter-98025.html
Then start with the tests I described earlier.
Mar 26, 2018 | 08:19 PM
#13
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I’m not gonna pay anyone, I’ve got 300 plus a starter into this beast. I can problem solve electrical w directions if that makes sense. Going at it blindly, I’ve got no clue on the workings of these efi gas monsters. If I’m told where to look, how and what to find or look for I can def do it.
Mar 26, 2018 | 09:12 PM
#15
I’m not gonna pay anyone, I’ve got 300 plus a starter into this beast. I can problem solve electrical w directions if that makes sense. Going at it blindly, I’ve got no clue on the workings of these efi gas monsters. If I’m told where to look, how and what to find or look for I can def do it.
Once you established voltage and ground at the pump it is pretty clear you have a dead pump which isn't that uncommon. You also want to replace the fuel filter if you have a bad pump, a clogged filter makes the pump strain more than it should, stress on the pump is what makes them die (along with running it on low fuel ALL the time, the pump is cooled by the fuel.. Skip a trip or two to MC'Ds or those two dollar soda pop at the checkout and fill the tank *eyeroll*!!)
Please forgive the laughter at "300$ and a starter", you are driving a thirty year old vehicle you know(?). If you expected no maintenance you might have bought the wrong vehicle and should look at a lease vehicle with warranty..
Anyways teasing aside electrical work is much more straight forward and simple than most people think. Grab your multimeter and get to work! (If you can read a tape measure or ruler you can work a multimeter)
Last edited by Co_94_PU; Mar 26, 2018 at 09:13 PM.
Mar 27, 2018 | 03:59 AM
#16
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I have zero problems with maintenance and tinkering. Like I said I can do it all, I just get overwhelmed w electrical and unless I have a plan of attack I usually give up. I’ll tackle the fuel pump testing tomorrow. I’m off to northern va now to give a speech this evening
Mar 27, 2018 | 06:02 AM
#18
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I don’t, I also don’t own a computer, if I could rid myself of my cell phone and return to an old grey and white cordless att phone with extendable metal antenna for the house I would. I may be able to get one downloaded at work or my parents home.
