R33 Won't Fire

[govich]

Hi guys,

Well after recently fixing the fuel system, the car's decided to crap itself again.

Basically, if i leave it for a few hours, the car will kick over and maybe struggle around 200-250rpm (checked on e-manage ultimate) but eventually turn off. Subsequent attempts to start it result in just cranking and cranking with the engine sounding like it's on the edge of starting.

Fuel pump primes fine, i've checked fuel pressure just before the fuel pressure reg and it's spurting out plenty while cranking.

The E-manage ultimate registers an AFM voltage while cranking so it's getting air. Playing with the throttle while cranking or while it's struggling makes no difference.

The EMU also shows the RPM it's cranking over at, so the CAS is working.

The spark plugs shouldn't be fouled as the car drove fine the night before and simply refused to start in the morning.

All fuses under the dash, in the engine bay, and in the boot are fine.

Is about 180-250rpm the correct cranking speed? It sounds like the normal speed audibly.

Any other ideas? I'd appreciate any help here.

Cheers guys, I'll post up the fix when i get it again.

Edited October 5, 2007 by govich

[govich]

OK i've checked the pulsing to the injectors and that's fine, the grey wire gets constant 12V and the white wire gets grounded on and off.

I found my battery was down to 11.8V so i'm charging it overnight, it could be that the battery is too flat to run the car. I doubt it though as the morning it wouldn't start was only about 7-8 hours after it'd been running for a good 20 minutes, and i've been cranking the car on and off for a few days . It's charging at the moment though, i definitely hope it's something simple like this

Would the car struggle to start/run if the voltage was too low? It's still cranking fine so i'm thinking these two are mutually exclusive.

Edited October 5, 2007 by govich

[RPR33]

I dont think it would be your battery mate, mine was going flat for a while but as long as the starter motor cranked it started!!

[govich]

I dont think it would be your battery mate, mine was going flat for a while but as long as the starter motor cranked it started!!

Cheers, yeah, i don't know why i thought that'd fix it anyway.

Has anyone had a fuel pressure regulator fail on them? What are the symptoms like? It's all i can think of at the moment.

[govich]

Now i've discovered something interesting. I can't get error codes out of the ECU because there's no power to either of the pins on the Consult connector (tested with a test light), so bridging them does nothing. Anyone in sydney got a spare factory ECU they wouldn't mind lending me for about 5 minutes?

I'm stuffed for today, can't be bothered testing more..

Edited October 6, 2007 by govich

[aphid]

i've had similar symptoms to what you're describing.. turned out to be the engine temp sensor

[blind_elk]

What happens if you give it some throttle while cranking, then keep some throttle after it starts?

Generally, if you keep cranking and it won't start, you will flood the engine. In that case, you need to give it FULL THROTTLE while cranking, and maintain some throttle once it fires.

[govich]

What happens if you give it some throttle while cranking, then keep some throttle after it starts?

Generally, if you keep cranking and it won't start, you will flood the engine. In that case, you need to give it FULL THROTTLE while cranking, and maintain some throttle once it fires.

Playing with the throttle does nothing while cranking and nothing while it's turning over at 200rpm.

I think aphid might be onto something. The coolant temp sensor gets no 5V signal when the key is turned to ignition on (specified by the engine manual). I think there might be more wiring shenanigans at play, might expose a bit of this wire at the ecu and see if it's sending out a signal. At this point i think either some of the ecu is stuffed or there's some wiring that's been knocked out somehow (since even the consult plug gets no power).

Thanks guys

Edited October 7, 2007 by govich

[govich]

OK, so i've now done the following:

- Tested the fuel pump and fuel system, pumping fine to just outside the rail.

- Pulled a coil off and put a spark plug in it against the block, pulled out the crank angle sensor and turned it with ignition on, can hear injectors ticking and there's spark.

(why the hell isn't it starting just from the above two?)

- Water temp sensor gets power, reading of ~3V seems good at about 20 degrees (from the engine manual) <- is there a better way to test the operation of this?

- .. a whole bunch of continuity tests on ecu pins, all fuses are fine, afm voltage is OK (1V) when cranking.

I'm out of ideas. Any tips greatly appreciated.

Edited October 11, 2007 by govich

[govich]

- Tested the fuel pump and fuel system, pumping fine to just outside the rail.

- Pulled a coil off and put a spark plug in it against the block, pulled out the crank angle sensor and turned it with ignition on, can hear injectors ticking and there's spark.

(why the hell isn't it starting just from the above two?)

Problem solved. Knew from the above two that something was sus.

Anyone in this position, have a look at your security system, they can play all sorts of shenanigans with the car. Deactivated it and the car was a black smoke machine for about 20 seconds, held it on the throttle though and it's purring now.