Idles for 10 sec, then rough idle and stall 1995 HELP!

[Bonznfc]

1995 4runner that I have had for almost 6 years. It sat for about 10 days (which killed the battery, a whole other issue) and now it will stall out almost immediately. (I fully recharged the battery before attempting.):sad:

-Idles normally for about 10 seconds then starts to chug and dies.
-I hear hear the fuel pump kick on when I turn the key to on.
-Its not throwing any diagnostic codes.
-Checked the air filter and it does not seem clogged.

My next step is to get a fuel pressure gauge and check that the fuel pump is actually pushing fuel. However I can repeat the start and stall which seems to tell me it is initially getting fuel.

Any ideas??? I need this thing to run and no diagnostic codes are giving me no where to focus on. Thanks for the help.

 

[the_dingman]

Which engine?

 

[mikekfr]

Changing the fuel filter's always a good place to start, even if it doesn't fix it, that's 1 thing off the maintenance list, as well as the troubleshoot list.

 

[flyinhawaiian01]

Can you keep it running with throttle input? Does it die faster if you throttle down on it within those 10 seconds, or is it always exactly 10 seconds?

Did you check codes, or is the check engine light just not flashing. The ecu stores codes but some do not show up with the check engine light without the problem showing up a second time.

Check the intake pipe for leaks too, although that will usually kill the engine in a couple of seconds, not 10.

 

[Bonznfc]

It is the 3VZ-E engine. The engine is not throwing any codes no matter how many times I try the startup. The check engine light just flashes.
If I put the throttle in I can get it to rev up but it still cuts out right around 10 seconds.
I am going to replace the fuel filter just to do it and see if I can find an exhaust leak.
Thanks for the help so far.

 

[Ahlem]

Had the exact same issue. The cold start injector helps supply fuel for the first couple seconds to mask the fact that we had 3 clogged injectors. Once it stopped injecting, the clogged injectors made the motor run on 3 cylinders.
You can verify this by un plugging your cold start injector and see if it runs poorly right out of the gate. See the running on 3 thread with photos, charts and graphs posted starting in January.

 

[Bonznfc]

Had the exact same issue. The cold start injector helps supply fuel for the first couple seconds to mask the fact that we had 3 clogged injectors. Once it stopped injecting, the clogged injectors made the motor run on 3 cylinders.
You can verify this by un plugging your cold start injector and see if it runs poorly right out of the gate. See the running on 3 thread with photos, charts and graphs posted starting in January.

Just tried this and now she won't fire up at all, which means the cold start injector is working and something else is the issue. Just so I am sure I understand the system:
Key -> on fuel pump runs
cold start injector provides fuel for initial start
then fuel pump pushes fuel to injectors to maintain the engine running. Unless all of the injectors are completely clogged.

So what would cause the fuel pressure to stop post the initial start sequence??

Thanks

 

[Bonznfc]

Heres a quick video link of the attempt pre-removing the CSI

http://youtu.be/pFEB8tcrJbE

 

[flyinhawaiian01]

I dunno what part is used for the 3VZE, but there's an injector igniter box that controls injection, this is what it looks like on my '85 supra, I believe its similar to my '87 truck's too (can't recall and truck's in the garage, I'm in the shop right now), perhaps its the same as the '95:

I believe there's a whole procedure to test the igniter. I do know that its a negative trigger from the ecu to that box, so you should see +12 at the injectors.

Let us know what it turns out to be, this would be good info to keep around for others!

 

[Bonznfc]

The ignitor tested fine per the service manual. And it still starts for a few seconds so I think the spark is good. I am getting the fuel pressure gauge today. I jumped B+ and kept the fuel pump running with the key on. It sounds like its pushing fuel but who knows.
-When checking the electrical connection to the injectors, I noticed fuel leaking out of the forward most injector whenever I touched the top. Could this have anything to do with it?

Thanks and keep the suggestions coming

 

[flyinhawaiian01]

I doubt it has anything to do with it, unless you find a huge puddle of fuel there along with it gushing out when you turn the fuel pump on. Sounds like a separate problem and you'll need to replace the o-rings on the injectors. They're easy to do, just unbolt fuel rail, pop 4 injectors out, replace o rings. While you're at it, might as well have them tested and cleaned. Not sure where you live, but there's lots of places that do them, although my preference is:

Fuel Injector Cleaning


I've had them do 5 sets of injectors now, they always do a fantastic job, send you a whole bunch of info for each injector and give you the full specs on before/after. They will also replace those o rings and bottom rubber seals too.

At this point, your plugs should be swimming in fuel! If they're not completely soaking wet, you definitely don't have fuel coming out of the injectors. I have never heard of all 4 injectors dying at once, and unless you sucked up a ton of rust and crap from the fuel tank, AND that all made it past the fuel filter, AND it got to all the injectors spaced evenly enough to clog the screens, AND it went past the screens and plugged the pintle inside the injector, you are simply not getting the injectors to open up and shoot fuel.

Pull the rail off, turn the pump on by having key in on ignition, not started, stick your finger inside the MAF and open the door slightly, the pump will turn on (or you can jump the connections in the test cable, your choice, its easier for me to stick my finger in the maf door, more control too when it starts flowing).

Flow a bunch of fuel out of the rail, try to catch it with a bucket or something (I'm being "eco friendly" here, in case some tree huggers are reading! :thumb Let it flow for about 10 seconds and see if the flow shuts off or slows down. If not, then let everything dry off. get multimeter and check at the injector's wiring connector, see if you have proper voltage and test for ground on the other side of the wire when starting (you'll need two people for this).

Its either flow of fuel or electrical not opening injectors, that's all it can be at this point.

 

[Bonznfc]

I have checked the voltage at 2 injectors and they are showing 12 as the engine is cranking. Can you get to the injectors without pulling the whole manifold off like the FSM says? Thanks as always for the input

 

[Bonznfc]

Also where the hell do you hook up a fuel pressure test kit on this thing

 

[Bonznfc]

Update: got it running and she seems to be doing good.
I pulled off the AFM and tested with a meter and everything checked out fine. Cleaned off the prongs on the AFM wire connector with a wire brush.
Next I hooked up the fuel pressure test kit and its pushing 46 psi which is a little high but close. After pulling off the test kit she is now running fine. So I am pretty sure it was the AFM connection.
Thank you for the advice and your time. You guys are great. :thumb::thumb:

 

[flyinhawaiian01]

Wow! did not see that one coming!

Glad to hear you found the issue, only thing I could think of is the switch inside the afm for fuel pump, guess the wire harness and/or contacts could have been that dirty that it would shut down the power to the pump.

In case you wanted to see what's inside the afm, here ya go:

Mass Airflow Sensor:

Switch for fuel pump, open circuit(pump not on):

Closed circuit (pump running):

Had to open mine up today, need to get smogged here in Boise, and this truck just likes to run rich, so I have to turn the gear back 8 teeth to get it to pass (which is 5 teeth from stock setting leaner)

 

[Jdrum1]

Mine acted similarly.

Assumed it was the AFM, and it turned out that the wiring harness connection to the ignitor had gotten moisture in it.

A day to dry, and two zip ties to strap the harness down tighter, and all seemed fine.

 

[Ahlem]

So, Where did you tap in to test your fuel pressure?