The truck does start, but only after pumping the gas lots, and lots of cranking. When it does come to life it is very rough. Changed the fuel filter and when I had that off I checked to see if the fuel pump would dump fuel out of the intake line to the filter, it did not. so I'm not sure if it is the pump since it can still run and start, but just barely. any advice would be great. Thanks
Thanks for choosing FixYa. Sounds like your fuel pump Nathan. Sounds like it is close to failing. You need to make sure your fuel pump is getting 12V of power or close to that. You could have an power issue. If it is not getting the full amount of power, it can do things like this. If power is good, it is probably the fuel pump going bad.
SOURCE: 1985 Toyota Corolla Intermittently runs rough-no power
Try this: Remove the two (primary & secondary) vacuum diaphram covers & inspect the vacuum diaphrams. If there is any evidence of distortion at the diaphrams, expect to get the condition that you are describing.
SOURCE: Toyota 02 is stalling, won't idle
Check the voltage of battery with voltmeter.. It is sometimes possible that if voltage of battery drops and jump start is needed, your computer will only charge to the last voltage that was recognized which would be when jumped...Try and charge the battery if possible I would actually suggest that you have your battery tested at local auto parts store and if it is presumed in good condition ,let them charge for you to max capacity . If battery has been tested and labeled as no good replace if necessary... Oh, and first thing you should do is make sure your positive and negative battery connections are clean and tight...if this didnt fix problem please give more info on what was found when advice above was followed...Good Luck!!!!
SOURCE: 1986 Toyota pickup, Hilux fuel pump
NO the problem most likely is your carb. draining down or accelerator pump not working.
SOURCE: 1992 toyota celica gt 2.2 starts runs rough then dies
Sounds to me like the fuel pump is worn out. They DO wear out. And even though they seem to be working, the brushes in the electric fuel pump may not be contacting all the commutator, thus making the pump weak. It may start the motor but can't maintain normal running pressure (27-35psi). Have you run the car out of gas shortly before this problem surfaced? If you have then it's your fuel pump. It was damaged when the tank ran dry. Even though the pump may seem to be working, it's still badly damaged and needs to be replaced.
Just as Matmenzies has stated, get a fuel pressure gauge and test the pressure. I'd start with a complete check of all your vacuum lines. Check for cracks on the vacuum hose that connects to fuel pressure regulator on the fuel rail. Also, if you can, get a hand operated vacuum pump to check the regulator. If you can place a vacuum on the regulator and it holds, I'd say move on the fuel pump and check it.
BTW, if the fuel filter has been changed, you may want to check to see if it was installed backwards! Some fuel filters are valved and will cause symptoms like this. However, this is an immediately noticeable mistake and you haven't provided enough info for me to say more. I'd pull it and check that it has any flow at all. You could have sucked in a big dirt ball and blown it right into the new filter, effectively stopping fuel flow. Then I'd blow out the fuel lines, just to be sure.
Start with these 2 things and post what you find. We'll go from there.
SOURCE: 94 4Runner 6cyl. 3.0 4x4
If the fuel pump operates with with a jumper at data link.That clears that the fuel pump is running.So check the EFI relay and the fuel pump relay. Now what is EFI relay:--- EFI Main Relay The EFI fuse supplies constant battery voltage to EFI main relay. The EFI main relay provides battery voltage to +B terminal of circuit opening relay (some models) and data link connector. Depending on model, EFI main relay may either be turned on directly by ignition switch or by M-REL terminal of Engine Control Module (ECM). The EFI main relay may also provide battery voltage to +B and +B1 terminals of ECM when ignition is turned on. The EFI main relay is located in engine compartment relay box. NOTE: Circuit opening relay is used on all models. Circuit Opening Relay Circuit opening relay controls fuel pump circuit. The Engine Control Module (ECM) receives an input signal at STA terminal when engine is cranking. Starter signal is also applied to STA terminal of circuit opening relay. Starter signal energizes circuit opening relay during cranking. Circuit opening relay then provides voltage to fuel pump or fuel pump relay.The circuit opening relay is grounded by ECM through FC terminal.Fuel Pump Relay & Fuel Pump Resistor .Fuel pump relay receives voltage from circuit opening relay and operates fuel pump. Fuel pump operating speed may be varied by Engine Control Module (ECM). When ECM grounds fuel pump relay, relay contacts close, and voltage is supplied through fuel pump resistor, to fuel pump. This changes fuel pump operating speed. ---------------------- As there are many other possibilities to check out of the mentioned procedure.But as you said fuel pump works with jumper wire and the fuel pump relay is replaced,on as per that i think the problem is the Fuel pump relay connections.The relay ground wire is connected to the ECM.If this wire is not connected properly or if this ground wire is got short or in-case not connected,then the ECM will not send signal to fuel pump relay to get started so it will not let the fuel pump start.But in jumper wire connection the relay is bypassed so no ground connection required and due to that fuel pump works. Thanks. Keep updated for any more query. You can rate this solution and show your appreciation
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