03 tacoma 2.7 starts and dies

Hi all. New member as of today. i have an 03 tacoma pre runner 2.7 automatic 2wd. truck just died on me while driving, it will start then die. put new fuel pump in, same thing. swapped main relay with new one. no change. pulled spark plug and checked spark, it is good. injectors fire when started then no injector pulse after that. If i turn key off then i crank it over it starts and dies. if i dont turn key off and crank it over i have no injector pulse, but still have spark. Any help would be appreciated

 

yes. all fuses are good, swapped out circuit opening relay with new one. i also checked every ground that i could find with Mitchell on Demand. Mitchell does not have a No Start trouble tree for this vehicle. Just for the knowing, I am an ASE Certified Mechanic for 30 years. This Problem is just eating my lunch. Fuel Pump Runs and Coils fire, Just the injectors don't fire once engine is started and dies without turning key off then back on in the start/crank position. Injectors only fire for a few seconds before it dies. While the key is left in the run position, i crank it over, and i have fuel pressure and spark, just no injector pulse with noid light. CPS shows 1970 ohms, which is in spec. My scanner shows RPM. No Codes! Thanks

 

My scanner is showing 86 degrees. Which is the temperature here in north east fl.

 

Have you tried starting the truck with the MAF disconnected? Not sure if it will change anything, but if it does then it might be a clue.

 

unplugging maf does not help

 

I'm having the same problem on my 02 tacoma 2.7

 

see if this helps. at this point in time all I can think of that would require a new start/crank signal is the IGF output from the igniter.

put you scanner on her and see what she says both current and pending.

 

This above ^^^. check sensors and ignition if those are good might be a bad ECU...

 

I wouldn't believe that it would be a bad ECU just yet. There has to be a reason why the computer is not allowing voltage to the injectors. I am not experienced with Toyota but if it were my truck with these symptoms I would be looking at an oil pressure switch or sensor. I believe that there is a reason why the fuel is shut off.

 

An ECU definitely would be the last resort / final step. 1st gen tacomas aren't to complicated, the oil pressure sensor is nothing but a light on the cluster and would not prevent it from running even with no oil, lol trust me I've tried on other toyota models newer than a first gen tacoma. I'll check out some wiring diagrams and see what powers these injectors, fuses, relays grounds.

 

Read this, and see if it helps .

 

I got to thinking about this and there are few things that I can think of. It is the "reset" via cycling the ingition that has me scratching me head.

does this truck have an anti-theft system?

The ignition switch has 2 feed wires to power the truck, IG1 and IG2. IG2 is the one that feeds the elctronics for the system. Verify at a convienient point that there is power at all times the key is in the ON position.

The other thing I would check is to see if the Fuel Injection relay stays powered up during the re-crank.

 

No it doesn't. I was told to check the idle air control valve.

 

MIL on? Any codes? Is your anti-theft/security system behaving normally? This is exactly the behaviour I had after water got into a connector and shorted a couple of pins for the anti-theft system.

 

Sounds like the ECM sees a fault and shuts off the fuel.

What codes have been pulled.

 

No anti-theft.

 

How does it behave when it dies? Does the cluster light up like when you stall? Could it be a bad ignition switch?