Car is starting then dies instantly
05-11-14, 12:20 AM
#1
Car is starting then dies instantly
So last week I posted a thread about how I was getting no spark. Well that's resolved but the car still won't start, or rather stay started.
It cranks, and fires, then just when any one would normally stop cranking it and just let it run it dies.
Its jumping to right around 1500 rpm every time rather quickly then just falls on its face. And stops firing so it dies pretty quick as well.
Things i have tested:
-Spark: This was the first problem as I wasn't getting any. I fixed that by properly installing the FFE cas bracket thing (I had it flipped) and also an ecu plug wasn't plugged all the way in (heh.. yeah.) But i made sure those are all good now.
-Fuel: Well it starts so I figured fuel was good. But i don't know how it works from injecting fuel for starting it and switching over to the actual fuel map once its starting and idling. So i tested them according to procedures on here, and yeah they have power and ecu signal and click when cranking so i figure that those aren't the problem. (Injectors are ID 1000 pri and 2000 sec btw). Fuel pressure is constant at ~43psi
-Air: Well i have the intake off, just the lim, uim and tb is whats on so yeah theres obviously air.
-Compression: fresh rebuild from banzai, not the problem.
-TPS: checked all the voltages and stuff, according to procedures on this site and the FSM. It all checks out
-MAP: Same as above. Only I'm using the AEM 3.5 bar so at 0psi gauge pressure the voltage signal might have been different. It checks out good according to the AEM site.
-Throttle cable: Seems to be set perfect and was working before. ever so slight slack at 0-throttle.
Things i didn't test:
-Vac lines: I have literally everything deleted. Single turbo setup with no emissions. Vac lines that hook up to the uim are: fpr, MAP, and one to the boost controller in the car. BOV isnt on at the moment. All other vaccum lines for boost control stuff are run off a vac manifold thats hooked up to the IC piping. Everything else is capped off and shouldn't be an issue so i didn't check. Even if I forgot to cap something off, it should cause whats happening.
I will check that now that the uim is off from injector testing though.
Car is fresh off a build, as mentioned ID 1000 pri, 2000 sec, twin power, single turbo, ecu is a Link G4 plug in (one in the factory ecu case)
I have no idea what i need to do at this point. It seems like every individual component is working but it obviously isn't if it's not staying started.
I want to turn and say its an ecu issue but the ecu was on a car with the exact same setup, (turbo, injectors, map sensor, etc etc) so at SOME point in time, the ecu was good. It was shipped to me and i kept it on a shelf indoors until a weeks or so ago when i tried using it. Point being, ecu should be okay. I have the PClink software so i could hook it up to a laptop and monitor some parameters but even then I don't even know what id be looking for.
One thing that *might* be of interest is that at key on the tach rises to redline then comes back down and you hear a beep. Sounds like the coolant buzzer going off for 2 or 3 seconds. Could this be anything of significance or just something the ecu does? I just figured i'd throw it in since ive never seen that happen before.
What do i do at this point?
It cranks, and fires, then just when any one would normally stop cranking it and just let it run it dies.
Its jumping to right around 1500 rpm every time rather quickly then just falls on its face. And stops firing so it dies pretty quick as well.
Things i have tested:
-Spark: This was the first problem as I wasn't getting any. I fixed that by properly installing the FFE cas bracket thing (I had it flipped) and also an ecu plug wasn't plugged all the way in (heh.. yeah.) But i made sure those are all good now.
-Fuel: Well it starts so I figured fuel was good. But i don't know how it works from injecting fuel for starting it and switching over to the actual fuel map once its starting and idling. So i tested them according to procedures on here, and yeah they have power and ecu signal and click when cranking so i figure that those aren't the problem. (Injectors are ID 1000 pri and 2000 sec btw). Fuel pressure is constant at ~43psi
-Air: Well i have the intake off, just the lim, uim and tb is whats on so yeah theres obviously air.
-Compression: fresh rebuild from banzai, not the problem.
-TPS: checked all the voltages and stuff, according to procedures on this site and the FSM. It all checks out
-MAP: Same as above. Only I'm using the AEM 3.5 bar so at 0psi gauge pressure the voltage signal might have been different. It checks out good according to the AEM site.
-Throttle cable: Seems to be set perfect and was working before. ever so slight slack at 0-throttle.
Things i didn't test:
-Vac lines: I have literally everything deleted. Single turbo setup with no emissions. Vac lines that hook up to the uim are: fpr, MAP, and one to the boost controller in the car. BOV isnt on at the moment. All other vaccum lines for boost control stuff are run off a vac manifold thats hooked up to the IC piping. Everything else is capped off and shouldn't be an issue so i didn't check. Even if I forgot to cap something off, it should cause whats happening.
I will check that now that the uim is off from injector testing though.
Car is fresh off a build, as mentioned ID 1000 pri, 2000 sec, twin power, single turbo, ecu is a Link G4 plug in (one in the factory ecu case)
I have no idea what i need to do at this point. It seems like every individual component is working but it obviously isn't if it's not staying started.
I want to turn and say its an ecu issue but the ecu was on a car with the exact same setup, (turbo, injectors, map sensor, etc etc) so at SOME point in time, the ecu was good. It was shipped to me and i kept it on a shelf indoors until a weeks or so ago when i tried using it. Point being, ecu should be okay. I have the PClink software so i could hook it up to a laptop and monitor some parameters but even then I don't even know what id be looking for.
One thing that *might* be of interest is that at key on the tach rises to redline then comes back down and you hear a beep. Sounds like the coolant buzzer going off for 2 or 3 seconds. Could this be anything of significance or just something the ecu does? I just figured i'd throw it in since ive never seen that happen before.
What do i do at this point?
05-11-14, 09:32 AM
#3
No I've actually tried various throttle positions and it makes 0 difference. Which is weird, I'm inclined to test that the ecu is actually receiving the tps signal. So far I just know the tps is working right- never tested continuity but in all other cases so far that's been fine
05-11-14, 10:23 AM
#4
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I'd suggest as an experiment running a hot wire direct from your battery to the fuel pump hot wire and I bet it will run. I suspect something is causing the fuel pump to shut off after it ignites.
05-11-14, 01:13 PM
#5
Although I am 99% sure this isn't the problem i will actually pay close attention to the fuel pressure gauge on the fpr next time I start it. Just gotta re install injectors and fuel lines from takin them out to test
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