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Adjusting Idle - Jimny G13bb (16v MPFI)

Posted: Wed Jun 17, 2009 9:17 am
by alien
Anyone know where to crank the idle up a bit on this engine? To be honest i haven't even looked at how to do it, its just easier to ask here =P haha

Thanks guys.

Posted: Wed Jun 17, 2009 9:31 am
by joeblow
its factory set in the ecu and there is no external adjustment.

Posted: Wed Jun 17, 2009 9:42 am
by lay80n
Whats it idleing at currently. As Joe said its factory set, so if you are having idle speed issues you will have to sort out the reason why.

Layto....

Posted: Wed Jun 17, 2009 9:53 am
by alien
reason why - added a snorkel =) so at idle its sucking a lot harder for air now...

Idling about 700rpm warm and dips to 500rpm with all accessories on, so just a touch lower than i'd like...

Posted: Wed Jun 17, 2009 10:35 am
by greg
The G13bb ECU takes input from the power steer pump to know when to rev harder. Find this wire to cause the idle up to occur.

Otherwise, why not put a hand throttle on it?

Posted: Wed Jun 17, 2009 11:09 am
by lay80n
A snorkel should any difference. If your motor is having trouble with the restriction of the snorkel at idle, then you have a bad snorkel flow problem.

Layto....

Posted: Wed Jun 17, 2009 12:52 pm
by alien
if thats the case its the snorkel hose being bent bigtime to squeeze between the battery and the panel to get out... how have you guys addressed that?

Posted: Wed Jun 17, 2009 1:57 pm
by nicbeer
alien wrote:if thats the case its the snorkel hose being bent bigtime to squeeze between the battery and the panel to get out... how have you guys addressed that?
Make a real snorkel :)

I take it you made it to come into the gaurd near the batt not like where mine comes in just after the battery tray.

Posted: Wed Jun 17, 2009 4:57 pm
by alien
yeah cos its an airflow snorkel (not exhaust style) - so its made to enter at the battery... i might pull the battery and see what i can do behind there to smooth things out for the hose.

That said though the airbox does restrict down quite small near the filter anyways, so it only has to have as much flow as that point...

Thanks for the input though guys =)

Posted: Wed Jun 17, 2009 7:02 pm
by trialjimny
on the g13bb engine you can manually modify the idle using the register on the throttle cable.

Posted: Wed Jun 17, 2009 7:05 pm
by Santos
you could shift the battery to the other side and have extra room for the snorkel?

Posted: Wed Jun 17, 2009 7:07 pm
by Gwagensteve
trialjimny wrote:on the g13bb engine you can manually modify the idle using the register on the throttle cable.
That's not idle speed then - that's just applying a little bit of throttle.

Steve.

Posted: Thu Jun 18, 2009 8:11 am
by lay80n
In computer controlled motors, the throttle blade position should not have to be altered. The computer will cycle the IACV to maitain what it is programed to think is a correct idle speed. Simply opening the throttle will not always fix it, and in some cars can acutally throw everything into fault codes.


Layto....

Posted: Thu Jun 18, 2009 6:02 pm
by trialjimny
that is just an easy solution that does not alter anything in the ecu.
for sure it fixes the effect but does not solve the cause.

Posted: Thu Jun 18, 2009 6:07 pm
by nicbeer
Alien - u dropped the snorkel off and it then works fine?

Posted: Thu Jun 18, 2009 8:42 pm
by alien
testing that tomorrow night - but a basic test of clutching while rolling above 40km/hr does lift the idle to 1k... below 40kmhr the idle starts to drop... so im guessing its snorkel restriction and the forced airflow of driving is overcoming it.

Posted: Fri Jun 19, 2009 7:56 pm
by alien
well - disconnected snorkle, no effect.
- removed air filter, no effect.

Any thoughts? I lose 200rpm on headlights, and average idle is around 750rpm...

EDIT: just so you know my exact setup:
- jimny g13bb top on vit 1.6 bottom using jimny wiring loom and computer.
Air in through snorkle & sierra airbox, out through extractors and 2" pipe with high flow cat.

Posted: Fri Jun 19, 2009 8:28 pm
by przooker
has there been any fuel map changes to compensate for the extra capacity and fuel needed? If not, then did it ever idle properly. As said before, disconnect the snorkel and then the filter and see what happens.

Posted: Fri Jun 19, 2009 8:57 pm
by alien
nope - no changes to ECU - but went great for 2 weeks, and has only started since snorkle install... and i've already done the disconnect of snorkel and airbox to no effect.

Posted: Sat Jun 20, 2009 12:23 am
by Santos
try reseting the ecu, maybe it still remebers the snorkel

Posted: Sat Jun 20, 2009 12:31 am
by alien
no no im keeping the snorkel =) lol

so my setup is satying as the g13bb top on g16a bottom with snorkel and sierra airbox... its just that disconnecting the airbox/snorkel had no effect on low idle - so it must be something else...

That said - how does one reset the ECU without damage? just a battery disconnect?

Posted: Sat Jun 20, 2009 1:08 am
by mr green
hey there alien, i have done exactly what you are playing with, mega low idle and poor performance with that setup. i used a 2.2k ohm resister in series to the temp sensor to richen the mixture to compensate for the extra air going into the engine. your idle will be corrected and you will find a stack more power. i never had it on a gas analyser to see what air/fuel it was running at that setup but he car went realy well by the seat of the pants test.
other thing to check is the dreaded flogged out crankshaft key, retarding the valve timing. 3 out of 5 g16 engines i have played with had worn keys.
but do part A first

Posted: Sat Jun 20, 2009 9:27 am
by BenT
alien wrote:so my setup is satying as the g13bb top on g16a bottom
Are you still running the G13 injectors, or did you swap in the injectors from the G16?

A guy over here who did the same conversion as you tells me his Jimny ran with the stock injectors, but went much better with the G16 ones.

Its probably running lean at idle.


Ben

Posted: Sat Jun 20, 2009 10:46 am
by alien
mr green - thanks for that! ill look into it

BenT - running g16 injectors already =)

Posted: Thu Jul 02, 2009 12:02 am
by mr green
any news?

Posted: Thu Jul 02, 2009 9:12 am
by alien
its in the workshop having the diff straightened and reinforced atm - so while the diffs out i've got the guy who wired it looking into the idle thing. I noticed a belt slipping sound now and then just before i took it in, not sure if a slipping belt is the cause of the low idle (doubt it but possible).

Posted: Mon Aug 17, 2009 8:43 pm
by mr green
so what happened??

Posted: Tue Aug 18, 2009 12:09 am
by alien
ah hah- just needed an idle-up adjustment at the computer... all good now.

Alternator belt also tightened so its not squeaking anymore either.