Announcement

Collapse
No announcement yet.

Fuel Pickup Problem

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    I read this with interest. From what I understand the fuel transfer is done by an electric pump in the main tank providing the flow for a jet pump to facilitate the actual transfer from the sub tank. Is this correct, because if so, this electrical pump could perhaps be working once ignition is on. A question I have is whether the low fuel light is based on the average of the two tanks as well juust like the fuel gauge or is triggered by the actual fuel level in the main tank the engine sucks out from. The latter would make sense, but it appears none of guys had a warning that you were actually out of fuel in the main tank. It a terrible thought having to trouble shot a diesel fuel system on the side of the road without a chance of a good wash up, so would like to think what options there are to prepare for this when it happens one day. To take another 20l of fuel insurance is a lot of dead weight, my thinking is more around a manual emergency transfer system. To replace the transfer filter with the OEM clips is also not risk free when they bind up with dust and grid. Have changed now the filter four times and the clips need replacing next time to be on the safe side.

    Comment


    • #17
      Your understanding of the transfer is correct - assuming by "jet pump" you mean venturi effect "pump".

      The fuel gauge appears to reflect the total amount of fuel left - so if the transfer filter is blocked and all the fuel is in the rear tank the fuel gauge will show 1/3 or so. The low fuel warning light won't come on - the car will stop and you'll be left scratching your head as to why there appears to be no fuel even though the gauge (and fuel consumption) says you should have heaps. There is no warning - it just gets sluggish then stops.

      20l of fuel probably isn't enough to guarantee to get you going again - we needed 40l. You need to fill the rear tank 100% so that the fuel starts filling the main tank. Jerry cans fill fairly slowly so most of the fuel goes into the rear tank first.

      Comment


      • #18
        Thanks Peter for confirming this. Next time I replace the filter by routine I will check how strong the suction of the venturi pump is. It seems to be a good system by design intent to keep two tanks regularly flushed, but in practice to have the low fuel warning also based on average fuel is misleading and serves hence no purpose. A real low fuel warning should be based on available engine supply so you don't stop unexpectedly. At least one can figure out that something is not OK when tank level and remaining range shows otherwise. A low tank level and low remaining range should be enough to alert to refuel.

        Comment


        • #19
          I dont know if this will work on older 150's (or if its actually usefull) but the main and sub tank levels for a 2016 can be read on the OBD port using Torque Pro as follows:

          Main tank in L
          PID 2129
          Equation AVG(20:A/2)
          OBD header 7c0

          Sub tank in L
          PID 212a
          Equation AVG(20:A/2)
          OBD header 7c0

          Notes:
          1. Not extensively tested yet
          2. AVG(20: Gives the avererage of the last 20 readings - the tank level is instantaineous and moves around a fair bit
          3. The value returned by the OBD query is in 0.5L increments hence the A/2

          Cheers
          -Rod
          2016 Prado GX 2.8L Auto (The third tourer)
          Y61 becomes Y62, R51 becomes R52. Nissan what are you smoking?
          2013 Patrol GU 3.0L Auto (The second tourer)
          2010 Patrol GU 3.0L Auto (The first tourer)
          1991 Patrol GU 4.2 Auto (The training wheels)

          Comment


          • #20
            I have been reading this thread with interest, I think I have a similar problem. It is intermittent which is a bummer. The first time it happened, we had filled up at Broken Hill and about 600kms later, the fuel light started to flash (there had been no non-flashing fuel light before). The fuel gage showed about half, what I would have expected. We were about 70kms from a town. When we fuelled, the filler neck gurgled and the fuel nozzle kept clicking off. It took 25 mins to fill, you had to wait as each chunk of fuel gurgled down. The amount of fuel it was consistent with what the fuel gages was saying. The fuel light was now off and away we went. The local Toyota guy replaced the filter between the tanks. The same thing happened on the next leg at about the half tank (according to the gauge and kms) point.

            Since this happened, we can can go half a dozen tanks where the system works as expected. Then we may go through one or more repeats of the above situation. Filling the tank always restores the fuel light to normal.

            Sometimes, the flashing light will com one at a quarter or one eighth mark. When this occurs, it is always easier to fill.

            My mechanic could not find the fault. He did confirm that the back tank was full (the gauge showed half) and the front tank was low.

            So, it seems the tanks do not equalise (intermittently). The fuel has been checked, filters cleaned. I just had the 120,000 service where many filters are replaced.

            I don't want to start replacing parts with expensive bits, so I'm trying to understand where the fault may lie. The obvious thing is something electrical with a dodgy connection effecting the pump between the tanks.

            I'd love some guidance on this.

            Cheers,
            Al

            2012 Diesel Prado GXL.

            Comment


            • #21
              And another one. Connie Sue. Hwy 40 km south of Warburton. Just stopped dead. The hand pump would not pump any fuel even after 20l added. Solution was to turn on ignition and then hand pump until fuel flows out of main filter. Keep fuel level above about 1/3 of a tank. 3000km of doing this worked well until I missed emptying another jerry in by about 100m. Repeated the step above and got going in 5 mins. At Yulara I managed to get 95 l in and it hadn't stopped.800-900 km seems ok but I wont for beyond that on the way home from Alice Springs. Further investigations back in Sydney. From all of the discussion it seems that lots of corrugations is the culprit. So it is the rear tank that has to come out?

              Comment


              • #22
                If it's a clogged transfer filter then you don't need to drop the tank - just change the filter. It's between the two tanks under the car. I'm not sure the problem is caused by corrugations - I've got Torque Pro showing me the two tank levels and on my 2014 GXL it always empties the rear tank (to 0L left) as quickly as it can. Perhaps if you had dirt/crud solidified on the bottom of the rear tank they might get loosened by corrugations but I can't see any other way it would happen.

                If you have an OBD scanner you can get it to read the two tank levels - main/sub. If your sub tank has fuel in it but the main tank doesn't then the transfer filter is blocked.This shows up on the dash as 1/3 tank left (since the dash just adds up the total fuel volume and doesn't care that the fuel in the sub tank isn't usable once the main tank empties).

                Comment


                • #23
                  If it doesn't sort itself after you replace the rear filter then other things that cause the issue are:
                  • Blocked tank breather located at the front of the rear tank (black plastic item that can be removed and cleaned see this video TOYOTA DUAL TANK FUEL TRANSFER ISSUES PREVENTED AND/OR FIXED! - YouTube)
                  • Blown Fuel Pump Fuse or Faulty Fuel Pump Relay in Engine Bay Fuse Box.
                  • Damaged wiring or connector in path from the Fuel Pump Relay to the In-Tank Fuel Transfer Pump located inside the main tank.
                  • The In-Tank Fuel Transfer Pump has failed (Toyota have it as a replace at 150,000 km/ 7.5 year service item so doesn't last forever).

                  Comment


                  • #24
                    Hmm. Still pursuing this. It will be looked at next week with a service including the rear filter. The more you search on here the more cases you find dating back to at least 2008 on both 120 and 150. Common symptom is motor just stops with about 1/4 to 1/3 of a tank BUT the causes vary. Some have trouble refilling the tanks. Some have fuel stuck in the rear tank, some have blocked rear filter and or blocked breather, some have dodgy fuses,some have a failed pump,some have pick-up problems.. Common is the fact that Toyota dealers appear to know of few cases and even fewer cures other than that will be $1500 please to replace everything. In my case fuel goes in easy. Today I managed to get the scangauge codes into my scangauge to read the 2 tank levels. 86 l in main tank and 23-24 in the back tank which aligns with the 400 odd km since last fill. 30 odd km of running around saw it drop to 19-20 litres so in my case it is NOT the transfer pump and probably not the between tank filter or the fuses. What is left? Most likely the fuel pickup. Thoughts? Has anyone come across cheaper parts than Toyota for pump and pick up? If the tank has to come out I am inclined to replace both pump and pick up as it has done 84000 km over 7 years. I noticed that the breather has a bit of diesel around it so that will be cleaned and checked next week as well. Another seemingly common link is dirt and corrugations.

                    Comment


                    • #25
                      404pug, Is yours a Petrol or Diesel?

                      As the in-tank pump operation and fuel transfer process is a bit different for each (Part Nos below were looked up on Partsouq for a 2016 150 but give you an idea)
                      Diesel - FUEL TANK & TUBE | Toyota LAND CRUISER PRADO GDJ150R-GKFEYQ 06.2015 - 08.2017 | Parts Catalogs | PartSouq
                      Petrol - FUEL TANK & TUBE | Toyota LAND CRUISER PRADO GRJ150R-GKTEKQ 06.2015 - 08.2017 | Parts Catalogs | PartSouq

                      The standard approach is to replace the whole pump assembly (Diesel P/No 77020-60470 / Petrol with sub-tank P/No 7702060430) that includes the housing, fuel tank float and sender, pump and pickup with strainer which is the big ticket item but much of the $1500 dealer charged cost you mentioned is actually labour to drop and potentially clean inside the main tank and reinstall.

                      If the pump (Diesel P/No 23220-30011 / Petrol with sub-tank P/No 23220-31460) is the only issue you can replace this separately but requires disassembly of the unit which may also have perished plastics so needs to be pulled first to confirm if feasible.

                      Your explanation that the pump appears to be operating correctly but cannot fully empty the main tank seems to be either a float/sender issue (over reading fuel remaining in tank) or possibly the bottom of the plastic shroud for the pump shown in the pic below has become blocked and fuel stops reaching the pump when it goes below the top of it. You won't be able to verify either without dropping the tank and removing the pump assembly so a bit of a pain but plenty of posts and videos available on how to do this if you wanted to have a crack yourself.

                      Click image for larger version

Name:	77020-60470__1.jpg
Views:	314
Size:	27.0 KB
ID:	769469

                      Comment


                      • #26
                        Thanks ptommo59. It is a 2016 diesel. It is interesting being able to see the contents of each tank separately on the scangauge. The main tank has not moved from 86 l but the sub tank is dropping at a rate that fits with the fuel consumption of about 10l /100km so it does seem that your analysis of a pickup problem is correct. If so I think the whole unit is the way to go because of the labour involved in getting it out. Toyota WONT be doing it at their rates. My local mechanic has done a few.. The question in my mind given the way the system works is whether a partly blocked rear filter is enough to stop the flow from the sub to the main tank when the main is low. It is getting new filters all round on Wednesday so when it gets to around 50 l in the main tank I will carry a jerry of fuel and stay out of traffic in case it stops again. If it does then a whole new pump and pickup etc will go in.

                        Comment


                        • #27
                          OK in a Diesel version:

                          The in-tank pumps only role is to act as a circulation pump drawing fuel from the main tank, circulating through the rear filter back through the venturi pump in the main tank and repeat. The pump is cycled on and off by I think the body ECU as needed. Even when the sub has been emptied there is return fuel from the engine fuel rail put back into the sub-tank so it still needs to be turned on periodically to empty this.

                          The venturi pump syphons the fuel from the sub-tank via a direct line so the only reasons it will not transfer is insufficient flow through the venturi pump (pump not working or blocked filter), the fuel line between tanks or pickup is blocked so can't draw fuel, or the breather is blocked so can't draw replacement air into the sub-tank.

                          The fuel to the engine is drawn from the main tank pickup by the engine fuel pump via the engine bay filter, so engine cut out due to fuel starvation is no fuel available at the pickup which is in the same area as the in-tank pump so has the same issue if the lower fuel inlet part of the pump housing has been blocked by debris in the tank (this shrouded area acts as a slosh guard when the fuel in the tank is lower than its top level (which seems to be around mid tank so around 40-50L remaining so correlates to your 1/4 to 1/3 tank on gauge when it runs out).

                          May be nothing but my Scangauge only ever reads max 83L for main when full (which I believe is normal) so there is something possibly odd with your 86L reading which could be 5V reference voltage high, sensor range/poor earth connection, or float arm position related. My sub-tank level only reads 59L at full so if yours is also higher than that could make it more aligned with the high reference voltage.
                          ptommo59
                          Member
                          Last edited by ptommo59; 01-10-2023, 04:24 PM.

                          Comment


                          • #28
                            Not sure about the max reading for the sub tank as I only installed the Scangauge codes for the 2 tanks this week. It has done about 400 km since a fill so the reading of the subtank looks to be on the money. Interestingly the tank of fuel where the problem first arose came from Balladonia on the Nullarbor and was very foamy and was followed by 900 km of corrugations up the Connie Sue before it died. Dodgy fuel or corrugations killing the pickup or simply a blocked rear filter? Who knows? I will after it gets down to about 50 l on the main tank after a new filter. No codes on Scangauge and no lights on the dash when it happens.

                            Comment


                            • #29
                              Its appears the venturi is finicky and peril sensitive (not the hidden filter). Toyota's book maintenance for 2018 models onwards requires the pump/venturi assembly to be replaced every 150K.
                              I had my Dealer skip that on my 150K service. I've programmed my Scangauge to read both tank levels and I watch it like a hawk when traveling remote.
                              I always carry spare fuel and a siphon hose (to get fuel out of the subtank) just in case.

                              Half a dozen times (in160K kms) I have seen the fuel level in the main tank drop when there was plenty of fuel in the subtank. However it eventually always corrected itself over 10-20Kms.
                              I might elect to swap out the pump/venturi assembly at 200K, and take the opportunity to inspect/clean both fuel tanks.

                              Comment


                              • #30
                                Hi RPP,

                                I have been watching both tank levels and the pump turn on/off parameter a bit more intensely over several weeks and it seems that when the rear filter is new the main tank stays topped up to full level (83L on my SG2) until the sub empties.

                                But mine did same as yours towards the end of the 20,000 km rear filter service interval and dropped the level on the main down to about 78L with about 20L remaining in the sub-tanks (It still steadily emptied the sub before starting further on the main).

                                So my assumption is as the rear filter gets restricted it takes longer for the venturi pump to transfer fuel across and may be sufficiently less that the engine fuel usage under some conditions to start draw down on the main tank, but as you say it will continue to try to catchup until the sub is emptied.

                                Definitely given your remote adventures I reckon changing the pump out as insurance at the 150,000 Km recommended interval or as soon as practical after is a good idea.

                                Have wondered if when there is a transfer issue you could disconnect the line from the sub-tank pickup and insert a small 12V electric fuel transfer pump with hose inline to the main rather than a syphon as a backup and this could also be used to empty jerry cans if your don't like holding them up to the filler :-)

                                Comment

                                canli bahis siteleri bahis siteleri ecebet.net
                                mencisport.com
                                antalya escort
                                tsyd.org deneme bonusu veren siteler
                                deneme bonusu veren siteler
                                gaziantep escort
                                gaziantep escort
                                asyabahis maltcasino olabahis olabahis
                                erotik film izle Rus escort gaziantep rus escort
                                atasehir escort tuzla escort
                                sikis sex hatti
                                en iyi casino siteleri
                                deneme bonusu veren siteler
                                casibom
                                deneme bonusu veren siteler
                                deneme bonusu veren siteler
                                betticket istanbulbahis
                                Working...
                                X