08 4.0 Tacoma Starts and Dies unless revved.

very interesting. I am out of ideas, you need to put a pressure gauge on the fuel rail, and verify it is a fuel pressure problem. That is as long as when you say "I jumper-ed the resistor", what you really mean is that you jumper-ed the harness plug that otherwise goes to the resistor.

Very strange that the symptom is such a perfect match, but the jumper does not solve the issue.

 

This is what I mean by how I jumped, the resistor.

 

I guess I could borrow a pressure gauge. However, I did replace both the fuel filter and fuel pump.

 

Fuel pump test results.
https://youtu.be/HTZub2CuD-E

 

Well, the fuel pump is not cutting off. Though I do not know what the proper pressure is.

Has me baffled, so might be worth to check for bad ground. Ground issues can present in very strange ways. Try using jumper cables from the battery neg, to the engine.

The only other thing I can suggest, is to put a volt meter to the battery and watch it when you start the engine. I once had an alternator go bad on a Chevy, where the alternator would short the battery intermittently, and when it did it would stall the motor, unless it was revved up high, then it would buck and snort and light up the dash; then clear up for a few seconds only to do it again. I found that one by disconnecting all the wires to the alternator, and it would run fine; reconnect the alternator and it was back to dying or bucking all over again. That faulty alternator was a recent re-man. First and only time I ever saw such a thing.

I really hope this one helps, because I am out of ideas.

Are you getting a check engine light? Any codes?

 

Thank you for the response. I will try those tests with the ground.

I am getting no codes or errors. I replaced the fuel pump and it ran better for a little bit, but then continued to stall.

 

It think this the most difficult issue I’ve trouble shot on this truck. Basically it’s a brand new engine and it continues to stall after every start. When replaced the fuel pump is idled ok for a few mins then died and has been dying after startup in 2-3 secs.

 

Been following this thread and just wanted to try and help and remember an issue similar where someone mixed up the fuel lines under the hood, the pressure line and return line. U say u replaced the fuel pump so did u drop the tank? By chance did u or is it even possible to mix up the pressure line and return line ?

 

I did drop the tank and installed an upgraded URD fuel kit w/external fuel filter. You can mix the lines up so I made sure to mark them appropriately. I even switched them under the hood thinking I had mixed them up and it wouldn’t even start.

 

Dang, hoping it was something easy like that.

 

Did you figure out what is going on? I hope so, and please educate us.

 

I’m waiting on new fuel injectors. I think I have narrowed it down to clogged fuel injectors.

 

ouch, Not sure that passes logic, if it were skipping and miss firing, then OK, but all the injectors clogged at once? and how does it run at all?

Possibly worse, if the fuel injectors are clogged, then what caused it? Please be sure to add a new fuel filter in the line and flush the fuel system; if injectors are all clogged; would hate to see the new ones get clogged up too.

I do wish you the best of luck. I only wish I could be of some help. Do continue to let us know what you find.

 

Ideas:

If the voltage drops too far, the ECU will mess up. Though this should give a check engine light. I do suggest you put a voltage meter on the battery wires or terminals (not on the battery posts, because we want to test for loose or dirty terminals). the voltage should not go below about 11v when cranking, and should be about 15v while running.

Another idea, is there are small LED injector testing lights, noid injector test kits, around $30 for a set, you just stick the wires from the test lights into the injector connector, while connected to the injector. These will flash with the injector pulse. Would be interesting to see if the injector pulses continue when it stalls, but is still rotating, or if they stop flashing immediately, and possibly explain why it stalls.

I think these are both worth trying, especially if you have not dismantled for the injectors yet.

 

He had someone put an engine in his truck, ever since then it hasn't been right. They used the injector that cam with the donor engine which isn't recommended. Multiple things have been checked and replaced already.

https://www.tacomaworld.com/threads/2006-tacoma-1gr-fe-engine-swap.850499/

 

Surprise!!

I had no idea that there was another thread. Heck, i posted on the Turbo BS thread, just because that is one I monitor and there are very helpful people there, now I see many of those helpful people are already involved in the thread you directed me to. Ha.

I also now see what a mess he got into, had no idea. For those of us that know; that thread made me chuckle in a dark and sad way. Mechanic? Not so sure; some of the mistakes indicate having no clue as to the common aspects of an engine PCV and/or Vacuum systems. Kudos for bravery of a Novice, but surprised to hear the swap was done by a "Mechanic"?

Any how, thanks for getting me up to speed.