Walbro 190lph pump question
08-07-2003, 09:43 PM
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Walbro 190lph pump question
I installed a Walbro 190lph fuel pump on my 2000 4runner a few weeks ago and it has been working flawlessly.
I noticed during the past week that when I turn off my 4Runner, sometimes the pump is still running (sounds like it is surging) after the key is shutoff and removed. I have to put the key back in and into the run position to get the pump to turn off.
I was going to recheck the wiring connections under the back seats but thought I would also post to see if anyone had any ideas?
I noticed during the past week that when I turn off my 4Runner, sometimes the pump is still running (sounds like it is surging) after the key is shutoff and removed. I have to put the key back in and into the run position to get the pump to turn off.
I was going to recheck the wiring connections under the back seats but thought I would also post to see if anyone had any ideas?
08-07-2003, 09:53 PM
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Check the fuse box under the hood near the battery. See if there is a relay in there labled fuel pump or EFI. You may need to replace it as it sounds like it is sticking.
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08-07-2003, 09:59 PM
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Thanks. I bet that is it, as I can definitely hear a distinct "click" after I turn the ignition back to the run position that sounds like it is coming from somewhere near the battery. I'll go find a new one tomorrow and swap it out.
Thanks again.
Thanks again.
08-07-2003, 10:07 PM
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I just checked the schematic for your truck. There is a relay labled EFI that powers the ECU, injectors, ignitor and so on. It also supplies power to a second relay which is controlled by the ECU. When that second relay is triggered by a signal from the ECU it allows the power from the first relay to pass through to power the fuel pump. That second relay is labled on the schematic as "circuit opening relay". There is no indication where it is located, but I will be it is in the engine bay fuse box.
Now what does not make any sense, is that both relays would have to fail stuck on for this to occur and keep the pump powered up. You would think that there is a slim chance of that.
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Now what does not make any sense, is that both relays would have to fail stuck on for this to occur and keep the pump powered up. You would think that there is a slim chance of that.
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08-08-2003, 06:14 AM
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Does the Walbro pull more current than the stock pump?
Maybe the relay needs to be upgraded too to prevent premature failure.
Gadget, any thoughts?
Maybe the relay needs to be upgraded too to prevent premature failure.
Gadget, any thoughts?
08-08-2003, 10:07 AM
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MTL_4Runner,
I am sure gadget has numbers for this, but I have not had any problems with the Walbro, and I know of many others with the same luck.
My guess is that it does pull more current, but not a whole lot more.
Dan
I am sure gadget has numbers for this, but I have not had any problems with the Walbro, and I know of many others with the same luck.
My guess is that it does pull more current, but not a whole lot more.
Dan
08-08-2003, 10:29 AM
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I do have the numbers for this, but not handy at work. Sometime this weekend I will try to post and let you know what the numbers are, but I do not think it is a concern.
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08-08-2003, 05:05 PM
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OK, here are snapshots of my fusebox. I am use to the EFI fuse and see the EFI relay. I don't see any other relays other than starter, heater, tail, defog, power outlet, headlight and dimmer (i.e. - no circuit opening relay). I'll dig the schematics out as well and see if it may be down on the frame, etc.
UPDATE: I found it. It is attached beneath the 2nd fuse block behind the drivers side kick/dash panel. You can't see it unless under the dash.
Gadget, I was thinking more about your last post where you were thinking that both the EFI and the circuit opening relays would both need to be stuck. Is that really the case? I would have thought that while the truck is running, if the signal from the ECU goes to the circuit opening relay to tell it to pump, then the ignition is killed, but the circuit opening relay is stuck, wouldn't the relay itself (regardless of the signalling), continue to pass unswitched power to the fuel pump?
At this point, I will run by the dealer tomorrow and pick up a new relay just to eliminate the possibility.
UPDATE: I found it. It is attached beneath the 2nd fuse block behind the drivers side kick/dash panel. You can't see it unless under the dash.
Gadget, I was thinking more about your last post where you were thinking that both the EFI and the circuit opening relays would both need to be stuck. Is that really the case? I would have thought that while the truck is running, if the signal from the ECU goes to the circuit opening relay to tell it to pump, then the ignition is killed, but the circuit opening relay is stuck, wouldn't the relay itself (regardless of the signalling), continue to pass unswitched power to the fuel pump?
At this point, I will run by the dealer tomorrow and pick up a new relay just to eliminate the possibility.
Last edited by derrick92130; 08-08-2003 at 05:52 PM.
08-08-2003, 07:09 PM
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Arrording to the schematic, the circuit opening relay gets the power it sends to the pump from the EFI relay. If the EFI relay opens then the circuit opening relay can not send that power feed onto the pump even if it is stuck closed.
So, if the schematic is correct, both relays have to be closed to power the pump. The chances of that are relay out there. OF course I could be wrong.
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So, if the schematic is correct, both relays have to be closed to power the pump. The chances of that are relay out there. OF course I could be wrong.
Gadget
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08-08-2003, 10:42 PM
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I just looked at the diagrams as well. I see what you are saying now. The EFI relay would have to be jammed, and either the ECM would have to be sending a signal to trigger the circuit opening relay or the relay would also have to be jammed.
Very strange. I am going to run by the dealer and pick up new relays for EFI and circuit opening and replace them. If the problem still exists, it sounds like I should pull out my voltmeter and start probing after making it hang.
I am sure it is something in the physical circuit or the relays. I know many are running the pump without issues and I am not blowing any fuses, etc. Besides it worked fine for two weeks before taking on this condition!
I'll post what I find and see if there are more ideas.
As always, thanks.
Very strange. I am going to run by the dealer and pick up new relays for EFI and circuit opening and replace them. If the problem still exists, it sounds like I should pull out my voltmeter and start probing after making it hang.
I am sure it is something in the physical circuit or the relays. I know many are running the pump without issues and I am not blowing any fuses, etc. Besides it worked fine for two weeks before taking on this condition!
I'll post what I find and see if there are more ideas.
As always, thanks.
08-08-2003, 11:14 PM
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I just pulled out my pump flow test sheets.
The Walbro 190 LPH pump draws 6.5 amps at 40 PSI and 7.3 amps at 50 PSI (475 HP) at 14 volts.
I the test sheets do not have amps listed on them for the stock pump, sorry, but,
The Supra pump pulls 20.1 amps at 50 PSI (726 HP).
I doubt the Walbro is to far off from the stock pump.
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The Walbro 190 LPH pump draws 6.5 amps at 40 PSI and 7.3 amps at 50 PSI (475 HP) at 14 volts.
I the test sheets do not have amps listed on them for the stock pump, sorry, but,
The Supra pump pulls 20.1 amps at 50 PSI (726 HP).
I doubt the Walbro is to far off from the stock pump.
Gadget
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08-09-2003, 04:05 PM
#12
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Originally posted by Gadget
I just pulled out my pump flow test sheets.
The Walbro 190 LPH pump draws 6.5 amps at 40 PSI and 7.3 amps at 50 PSI (475 HP) at 14 volts.
I the test sheets do not have amps listed on them for the stock pump, sorry, but,
The Supra pump pulls 20.1 amps at 50 PSI (726 HP).
I doubt the Walbro is to far off from the stock pump.
Gadget
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I just pulled out my pump flow test sheets.
The Walbro 190 LPH pump draws 6.5 amps at 40 PSI and 7.3 amps at 50 PSI (475 HP) at 14 volts.
I the test sheets do not have amps listed on them for the stock pump, sorry, but,
The Supra pump pulls 20.1 amps at 50 PSI (726 HP).
I doubt the Walbro is to far off from the stock pump.
Gadget
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Are the relays rated at peak or continuous?
I am only curious.......I don't think there is any problem with running the stock relay.
08-09-2003, 04:49 PM
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I do not have a clue what they relays are rated at, but I can tell you I ran that high draw Supra pump or quite a while and the only thing I had to do was upgrade the fuse.
So, did you replace the relays yet, or did the dealer have to special order it as usual?
Gadget
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So, did you replace the relays yet, or did the dealer have to special order it as usual?
Gadget
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08-09-2003, 09:06 PM
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OK,
The dealer had the relay for the EFI, but not for the circuit opening relay. I went ahead and replaced the EFI relay, no change. With the dealer wiring diagrams I learned that the circuit opening relay is actually not on the driver side, but is on the passenger side tucked up near the upper right vent. I went ahead and pulled the dash/glovebox out to take a look. Sure enough, there is a relay there. The relay I thought was the one this morning is just a relay for the remote fuse box.
Since I am waiting for the relay, I started doing some digging around. Here are my observations.
1) Here is my configuration. 2000 4Runner SR5, 3.4L, S/C, auto trans. I have the Walbro pump installed and the FTC1. I do NOT have the 305cc injectors installed yet.
2) For a couple of weeks after the install I did not notice anything different. For the past week, when I turn off the ignition I can intermittently hear the pump continue to run.
3) Actually, the pump doesn't run continuously when the ignition is turned off. It surges on and off. Today I was able to make it do it while I probed under the hood. I can hear and feel the ECU relay in the fuse box under the hood clicking on and off turning the pump on and off.
4) Roughly half the time the surging stops after a few seconds. The rest of the time it continues to surge until I turn the key to the Run/On position (without turning on the engine), stopping the surging and the pump all together. It remains off when I turn the key to the off position again. Since it is surging like this, I am thinking that it likely is not a sticky relay?
5) I "think" I can also hear something around the FPR when this surging is happening. I dug for a while with a flashlight and don't see anything out of place or any obvious broken vacuum lines, and obviously no fuel leaks.
It is almost as though the ECU is sensing a need to increase the fuel pressure right when the key is turned off and it just cycles in the on/off mode either until some condition is met or the key is turned back on?
Ideas? I am not sure of the signalling used by the ECU to turn the fuel pump on/off, and was going to start there and to validate the wiring for the FTC, although it has been in place for months without any issues...
The dealer had the relay for the EFI, but not for the circuit opening relay. I went ahead and replaced the EFI relay, no change. With the dealer wiring diagrams I learned that the circuit opening relay is actually not on the driver side, but is on the passenger side tucked up near the upper right vent. I went ahead and pulled the dash/glovebox out to take a look. Sure enough, there is a relay there. The relay I thought was the one this morning is just a relay for the remote fuse box.
Since I am waiting for the relay, I started doing some digging around. Here are my observations.
1) Here is my configuration. 2000 4Runner SR5, 3.4L, S/C, auto trans. I have the Walbro pump installed and the FTC1. I do NOT have the 305cc injectors installed yet.
2) For a couple of weeks after the install I did not notice anything different. For the past week, when I turn off the ignition I can intermittently hear the pump continue to run.
3) Actually, the pump doesn't run continuously when the ignition is turned off. It surges on and off. Today I was able to make it do it while I probed under the hood. I can hear and feel the ECU relay in the fuse box under the hood clicking on and off turning the pump on and off.
4) Roughly half the time the surging stops after a few seconds. The rest of the time it continues to surge until I turn the key to the Run/On position (without turning on the engine), stopping the surging and the pump all together. It remains off when I turn the key to the off position again. Since it is surging like this, I am thinking that it likely is not a sticky relay?
5) I "think" I can also hear something around the FPR when this surging is happening. I dug for a while with a flashlight and don't see anything out of place or any obvious broken vacuum lines, and obviously no fuel leaks.
It is almost as though the ECU is sensing a need to increase the fuel pressure right when the key is turned off and it just cycles in the on/off mode either until some condition is met or the key is turned back on?
Ideas? I am not sure of the signalling used by the ECU to turn the fuel pump on/off, and was going to start there and to validate the wiring for the FTC, although it has been in place for months without any issues...
08-09-2003, 10:20 PM
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That noise you are hearing near the FPR is the FPR. When the pump runs fuel is flowing through it and it is adjusting the relief valve to maintain proper pressure. Ignore that.
The ECU has no way of sensing or adjusting pressure. It is strickly mechanical by the FPR. There is no feed back sensor at all to the ECU. It has no clue if you have fuel pressure or not.
You may have a bad ignition switch. It would cause the EFI relay to close and power up the ECU which may send a priming signal to the pump relay. I am not competely sure what causes the ECU to engage the pump, but on some systems it will only activate the pump when there is an incoming RPM signal. This prevents the pump from running if the engine stalls from an accident to reduce the chance of a fuel fed fire.
Some systems will power the pump for a few seconds when the key is initially turned to ON to prime the fuel system. I do not believe mine does that, but yours maybe different.
You may want to check the FSM to see if there is a diagnostic for the fuel pump running when it should not be. If there is follow that diagnostic and it should lead you to the problem. Odd electrical things like this usually tend to be a bad or poor ground somewhere causing one system to float a ground through another causing the other system to act very bizzare. I would think this falls under bizzare.
I had a 90 Chev full size Blazer as my company car some years ago. Sometimes the pump would keep running after shut down. The fleet mechanics could never figure it out and I always hoped it would catch fire and burn up. It was a heap of junk. Never did.
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The ECU has no way of sensing or adjusting pressure. It is strickly mechanical by the FPR. There is no feed back sensor at all to the ECU. It has no clue if you have fuel pressure or not.
You may have a bad ignition switch. It would cause the EFI relay to close and power up the ECU which may send a priming signal to the pump relay. I am not competely sure what causes the ECU to engage the pump, but on some systems it will only activate the pump when there is an incoming RPM signal. This prevents the pump from running if the engine stalls from an accident to reduce the chance of a fuel fed fire.
Some systems will power the pump for a few seconds when the key is initially turned to ON to prime the fuel system. I do not believe mine does that, but yours maybe different.
You may want to check the FSM to see if there is a diagnostic for the fuel pump running when it should not be. If there is follow that diagnostic and it should lead you to the problem. Odd electrical things like this usually tend to be a bad or poor ground somewhere causing one system to float a ground through another causing the other system to act very bizzare. I would think this falls under bizzare.
I had a 90 Chev full size Blazer as my company car some years ago. Sometimes the pump would keep running after shut down. The fleet mechanics could never figure it out and I always hoped it would catch fire and burn up. It was a heap of junk. Never did.
Gadget
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08-10-2003, 01:22 AM
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ok, this is spooky. a week or so ago, i posted a question about my fuse box intermittently "clicking" after the car was shut off. sounded like it was a relay switching on and off. when i turned the ignition back on it would go away. well that didn't get resolved and i've just been putting up with it.
today i installed the Walbro. went for a test drive, came back, went inside, and when i later went back out to the car, it was doing the same thing Derrick described . . . an obvious, pulsing, whirring from the pump, and the clicking from the fuel box. both went away when the ignition was turned back on.
i would be willing to bet that the pump isn't the cause, just another symptom, but a more pronounced, noticiable one. i bet we have the same problem - bad ignition . . . has anyone checked the TSB list for the 2000 yet?
or maybe it's a san diego thing?
creed
today i installed the Walbro. went for a test drive, came back, went inside, and when i later went back out to the car, it was doing the same thing Derrick described . . . an obvious, pulsing, whirring from the pump, and the clicking from the fuel box. both went away when the ignition was turned back on.
i would be willing to bet that the pump isn't the cause, just another symptom, but a more pronounced, noticiable one. i bet we have the same problem - bad ignition . . . has anyone checked the TSB list for the 2000 yet?
or maybe it's a san diego thing?
creed
08-13-2003, 09:09 PM
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Just a short update since I got distracted when my wide band O2 sensor came in. I did hook up my BR-3 and did not find any FSM codes recorded due to the fuel pump running when it shouldn't be. I'm putting the 305cc injectors in this weekend since I finally got the new sensor installed. Once I have it basically dialed in I'll go back to the search for why the fuel pump keeps running.
08-13-2003, 10:08 PM
#18
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Originally posted by derrick92130
I'm putting the 305cc injectors in this weekend since I finally got the new sensor installed. Once I have it basically dialed in I'll go back to the search for why the fuel pump keeps running.
I'm putting the 305cc injectors in this weekend since I finally got the new sensor installed. Once I have it basically dialed in I'll go back to the search for why the fuel pump keeps running.
Just my penny's worth...
03-30-2004, 01:43 AM
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Any update on this??
I've been running the Walbro pump for several months without any probs, immediately after installing it I noticed that the fuel pump seems to run for a second or two after shutting the truck off--but it would stop every single time within a couple seconds of killing the engine.
Here's where it gets interesting. I installed the URD FTC/injectors and now the fuel pump sounds like it keeps running (surging?) after shutting down the truck. I can get it to stop by turning the ignition to the 'on' position and then back to 'off'.
This doesn't happen every single time I turn the truck off, but it happens once every 4-5 times I turn the truck off.
Really kinda odd (scary) that the fuel pump is making some crazy surging noise when the truck is off and I step out of the vehicle.I don't want my truck to burn down!
Have any of you guys been able to stop this from happening?
I've been running the Walbro pump for several months without any probs, immediately after installing it I noticed that the fuel pump seems to run for a second or two after shutting the truck off--but it would stop every single time within a couple seconds of killing the engine.
Here's where it gets interesting. I installed the URD FTC/injectors and now the fuel pump sounds like it keeps running (surging?) after shutting down the truck. I can get it to stop by turning the ignition to the 'on' position and then back to 'off'.
This doesn't happen every single time I turn the truck off, but it happens once every 4-5 times I turn the truck off.
Really kinda odd (scary) that the fuel pump is making some crazy surging noise when the truck is off and I step out of the vehicle.I don't want my truck to burn down!
Have any of you guys been able to stop this from happening?
03-30-2004, 12:32 PM
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That is exactly what mine was doing as well. It hasn't done this in a while. I was getting use to putting the ignition back to the ON position after I would stop the vehicle, then one day it just stopped doing it. I had been continuing to make changes to the maps on the FTC, but think that was probably just coincidental. I wish I could tell you exactly why it stopped, but I can't. None of the fuses or relay changes made any difference at all.
Now I have probably jinxed myself and it will start up again today! :-)
Now I have probably jinxed myself and it will start up again today! :-)
