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G16b Conversion - No Injector Pulse

Posted: Fri 02 Jan, 2015 7:48 pm
by Brad.Jones
Ok guys been a bit of hermit of recent times, spending most weekends in the shed rather than out there wheeling.
Today was the day to turn the key on my G16B conversion. I was half expecting some troubleshooting, and so here we are...

- Engine cranks and turns over fine.
- Tested spark, yep got spark.
- Fuel pump is pumping both at ignition on and during cranking.
- We have fuel pressure to the main fuel rail.
- No injector pulse, I tested this by wiring up a spare bulb out of my donor instrument cluster and wiring it up to one of the injector plugs.

Its a Mitsubishi ECU with a 7pin Dizzy (ie: the one with the coil, etc all built in).

About to go and re - check for the millionth time all my wiring, I think read somewhere that if the ECU does not get a proper ignition
pulse back from the dizzy that it shuts of fuel which sort of makes sense I guess. I'm thinking dodgy noise suppressor maybe?? How can I test this?

Anyone got any other ideas???

Re: G16b Conversion - No Injector Pulse

Posted: Fri 02 Jan, 2015 10:03 pm
by Brad.Jones
A bit more info, worked out the CEL had to be hooked up to the BLK/WHT wire from the main relay, instead of just a common ground and it works now (wasn't before).
Whats annoying is that the computer isn't throwing any codes. Just shows 12 to suggest everything is fine.
I got the list of codes from here: http://www.rhinopower.org/diag/cel.html

Checked the injector ground wires and I get 12V with the ignition on.
The plugs are dry as a bone too, the ECU just isn't firing the injectors for some reason.

Re: G16b Conversion - No Injector Pulse

Posted: Sat 03 Jan, 2015 9:01 am
by jono165
I had this problem too. The injectors won't fire if the ecu isn't getting a signal from the cam/crank sensor. For me it was just the noise suppressor on the firewall being half unplugged.

I had spark, the fuel pump primed, turned over fine, I had everything except fuel and it was just the ecu not getting the signal.

Re: G16b Conversion - No Injector Pulse

Posted: Sat 03 Jan, 2015 9:07 am
by jono165
This is a handy link too.
http://www.fixkick.com/EFI-1.html

Re: G16b Conversion - No Injector Pulse

Posted: Sun 04 Jan, 2015 4:58 pm
by Brad.Jones
Ok todays developments, way too hot to work on the car yesterday, spent plenty of time reading manuals and the fixkick site though.

After testing the injectors for pulse again I am now getting pulse. Turned out the globe blew at some point yesterday :?
So I am happy that the computer is doing its job for a while I was starting to think the comp was dead.

I rigged up the sierra throttle cable as a hand cable so I could turn the key and modulate the throttle at the same time.
If I hold it open a crack (I was thinking blocked idle speed controller) nothing but if I hold it to WOT
I get some nice rumbling sounds coming out my extractors, it doesn't actually run though.
Anywhere in between idle and WOT makes no combustion at all.

From my reading of http://www.fixkick.com/nostart.html
W.O.T cranking will clear a flooded engine. Wide open throttle + cranking , cuts the fuel injectors DEAD. (covered in operators guide)
After a few successful fires there is obviously no more fuel left and it goes quiet.
If I return the throttle to idle for a few seconds (still cranking throughout this process)
and then back to WOT I get some more exhaust gasses filling up my shed :)

So my thinking now is that the injectors are just dribbling / leaking and thus flooding the motor.
When I go to WOT it un-floods so about to try a second set of injectors that came with a second intake manifold I have.

Or maybe it's something completely different...

Re: G16b Conversion - No Injector Pulse

Posted: Sun 04 Jan, 2015 5:40 pm
by gwagensteve
Check you actually have fuel pressure at the rail, hoses hooked up properly etc. Sounds like everything is working but there's very little fuel getting to the injectors.

Re: G16b Conversion - No Injector Pulse

Posted: Sun 04 Jan, 2015 6:23 pm
by jono165
How long did the engine sit for before putting it in? Could the injectors be a bit sticky? Try tapping on them?

Re: G16b Conversion - No Injector Pulse

Posted: Sun 04 Jan, 2015 11:03 pm
by Brad.Jones
WoooHooo!!!! It just came to life.

Its always the simple things... who ever installed the dizzy last put the thing in 180 degrees out.
Found TDC on Cylinder No.1, lined up the dizzy and away she went.
Sounded like I just broke the sound barrier or something without any exhaust on.

When is AT again lol

Re: G16b Conversion - No Injector Pulse

Posted: Mon 05 Jan, 2015 8:39 am
by jonfromhamilton
It's always a special moment when the engine first turns over