[Veilsd]

Hi all, is it common for the G16b motor to have a dead spot in the rpm range of around 1500-2500rpm? I notice it mostly when the engine is cold but it is always noticable. I have assumed it is poor EFI tuning from Suzuki but I thought I would ask. It is a SE416 Vitara with aftermarket headers as the stock cast ones cracked which seems to be common. I have replaced the spark plugs and have a new fuel filter to put in but it won't fix it as its not starving for fuel at high rpm.

I come from a background in Subaru WRX and GTR Skyline's so the Suzuki's are new to me so no doubt I will have more questions in future haha.

[alien]

I've got a similar thing with mine that i'm trying to get to the bottom of.

Initial thoughts are that the choke is staying on (well, the temp sender that tells the computer) - possibly clogged coolant line not allowing enough flow to go past the sensor.

[MrRocky]

Had same cleaned coils and o2 sensor = fixed

[alien]

Might have to look at my O2 sensor. Coils are clean as. One is even brand new.

[MrRocky]

Brand new genuine ????
Aftermarket coils are shit

[alien]

Yeah genuine.

O2 sensor cleaning as simple as soaking it in fuel overnight???

[Veilsd]

Thanks for the replies, I will check the ignition and o2 sensor and see if that fixes it.

[alien]

i've had a development with mine... it does this on a cold start:



And smells like petrol as if its being heavily choked.

[MrRocky]

Pressure release when u take fuel cap off ?

[losfer]

Alien looks like an iscv prob.

[alien]

No pressure on fuel cap..

what's an ISCV?

[alien]

ah - idle speed control valve... thanks, i'll check it out!

[JrZook]

idle speed control valve. Its on the throttle body and could be full of gunk. One other thing to check would be the plugs for coolant. Fire it up when cold but shut it down soon after before it has time to clear itself, then check them.

[alien]

Cleaning the ISCV - as simple as removing the 2 torx screws on the section the plug goes into? Or do i need to take the whole thing off including the coolant lines? (Hope not).

[alien]

So it turns out, Suzuki in their wisdom didn't use a torx end, its some 5 sided version... FUCK.

Is there a down side to just leaving the ISCV unplugged?

Also - appears suzuki call it IAC (Idle Air Control) and part number is 18117-78F10 for jimny (bb).

[JrZook]

alien wrote:

So it turns out, Suzuki in their wisdom didn't use a torx end, its some 5 sided version... FUCK.

Shifter?

It will still run without the IAC but you will probably have to up the idle speed by the bleed screw to keep it running otherwise the rpm will be too low. May get a CEL as well.

But check them plugs as well. Simple to do and a good sanity check

[alien]

lol nar its this shape:



Yeah, it runs great with it unplugged so ill have a crack at just leaving it off till i can figure out how to get the bastard off to clean or replace it.

[GraphicX]

what's the trick to getting the top oxygen sensor out ? thought i'd pull mine just now & see, but can't get a good angle on it (seems to be around a 21mm - 22mm but can't get a decent angle with the spanner).