[Taff]

Just finished my G16B conversion into my sierra.

It ran great for the first day but now its idling high and running rich. checked all my sensors and wires and everything seems to be ok. the fuel pressure regulator is hooked up properly and seems to be working. Using the stock vitara fuel pump. the only thing i can find wrong is a hole in the manifold.

any pointers where to look for whats causing this?

[Westie]

Mate maybe s a temp repair get some muffler putty and while the engine is cold put some on the crack and let it set overnight then drive it and see if the crack is the problem, not sure how long it will last but maybe long enough to eliminate it.

[something_else]

maybe you need to get it tuned and try again, maybe its just running in still?

[Taff]

stock computer on a 160,000km old engine.

i think its run in by now

[royce]

check for vacuum leaks (even around hoses that appear to be in tight)

clean the airflow meter

easy way to tell if the ecu is upping the idle on purpose is to unplug the idle control solenoid next to the throttle body, also check the wax pellet thingy next to it (when cold allows air to bypass) is getting coolant flowing through

[Hybrid]

Sounds like an air intake leak

The hole is in which manifold?

If its the intake manifold it would explain the high idle and also more air would be getting into the engine than is measured by the air flow meter. This would show too lean at the o2 sensor so the ecu would pump more fuel in making it richer. (makes sense in my crazy head hehe)

If the hole is in the exhaust manifold before or near the o2 sensor the exhaust can sometimes draw air in through this showing a lean state at the sensor. Once again the ECU pumps excess fuel in and it runs rich. From what I've read though the exhaust only draws air in through a hole under certain conditions though so you wouldnt think it would be happening while idling. Still, its something to consider.

By the way I learnt both of those troubleshooting tips on the megasquit website when installing my own ECU.

[Taff]

whats the best way to clean the airflow meter? i will reconnect all of my intake pipes, didnt even think of a leak there.

the hole is in the exhaust manifold, it is pretty big.

[Scrawny]

If you can't find anything with the intake then my guess would be manifold. Use brake clean in a can or something similar to clean the air flow meter. Be careful if you use compressed air, you can damage them.

[Trojan]

Taff wrote:

whats the best way to clean the airflow meter?

Air Flow Meter Cleaner of course.

You can buy it in a can at any auto parts place. The CRC stuff is just called Mass Air Flow Sensor Cleaner.

[zooker]

Taff wrote:

the hole is in the exhaust manifold, it is pretty big.

If the hole if near the o2 sensor I reckon thats the cause. o2 sensor reads lean because of extra air and so ecu compensates by running rich. I had the exact same thing, fixed with a nice shiny set of extractors

[nissvit]

In the g16b ecu engine mapping the O2 sensor isn't used at idle speed.

In (both of) mine the exhaust temp at idle appears to be about 180 degrees c about four inches down the extractor, which isn't enough to get the O2 sensor up to the required 250 plus degrees where they start to generate the voltage that the ECU uses to determine how rich the mixture is.

My theory is the hole in the exhaust won't have that much impact on mixtures at idle for the above reason.

Only once the engine's throttle Pos sensor is off the closed mark and the O2 sensor is hot enough to generate voltage, it will the ecu start to use the o2 sensor to vary the duration of the injector opening, which then varies the mixture.


did you connect up the ecu check connector & check engine light?
have you checked the ecu fault codes?

have you checked that the throttle postion sensor wasn't knocked while the engine was out of the vehicle? that can confuse them a bit - that was the problem with mine initially.

[Taff]

have read on outerlimits how to reset the TPS sensor and will give it a go when i have some time.

i doubted the O2 would affect it after i thought about it a bit... and confirmed it myself as its exactly the same with it unplugged.

ECU fault codes dont know how to do it. nor did i install a check engine light. Looks like im going to have to wire that one up from scratch woohoo

[Taff]

Just went through my diagrams and had a play with my 'Monitor coupler' plug to my ecu but cant figure out which wire runs to the actual dash light.

it went missing in the great wire stripping incident of '09

[nissvit]

can you get a clear pic of the ecu pin outs (the connectors going into the ecu), and the connector going into the air flow sensor. If you have five wires going into the air flow sensor you have the earlier ecu type, the later type has just three wires.

I probably will have a diagram here somewhere that will match the pinout of your ecu. It might just take some time to find it.

There are quite a few different ecu's in different g16b's but they all seem to run the same error codes. ie code 12 ( one flash of the check engine light then a second pause then two flashes) is normal operation. These fault codes seem to be consistent for most suzuki (nippondenso) ecu's from the early 80's turbo F5a right through to the later H25a engine in the gen1 GV's.


Have you checked your fuel return line? if that line is blocked, that will create a higher fuel pressure in the rail, which may increase the amount of fuel being delivered making it rich....
but this won't fully explain the high idle speed as that is usually caused by additional air.

[nissvit]

have a look and see if either of these wiring diagrams look like yours.

[nissvit]

or this one...

[Taff]

mine is the first one with 5 wires running to the airflow sensor.

I will get the check engine light going this afternoon and see what results i can get.

[Taff]

still cant figure out how to get the check engine light going.

has anyone done this from scratch with just the monitor coupler plug? how did you do it?

[Taff]

I pulled the hose that runs from the IAC valve to the thermostat housing off and it was packed FULL of brown goop. cleaned it out and now shes running sweet

Still cant get a check engine light going though! is it even possible with just the 4 pin plug monitor coupler or will i need another wire coming out of the ECM?

[nissvit]

hi,

you will need another wire that runs into the ECU.

the four pin coupler is just the place you put the trigger wire.

I'll give words tomorrow, still cleaning up from a weekend away now.

cheers,
Chris

[Taff]

sweet, still trying to understand all the elements of this EFI stuff!

Its doing some weird stuff at idle. will idle high then drop too ~200rpm then pick itself up before it stalls and keep repeating. wasn't doing this before i touched the IAC valve but i also touched the ?air bleed? on the throttle body.

On the plus side its not running anywhere near as rich as it was. Did a full day up at double island today and used about 25L.... i was having a bit of fun with the extra power too

once i get the check engine light going should be interesting to see what it spits out.

your help is appreciated

[nissvit]

Check out the first wiring diagram.

there is a check engine symbol shown, if you follow the wire up it shows that it is fed from the ignition coil postive feed and runs into terminal A14.

to re-fit a check engine light, find a low wattage lamp (2-5watts- any larger and you will damage the ECU). Wire one side to a positive that is only fed when the ignition is on, wire the other side to the wire that is coming out of A14. The ECU will switch to earth internally to turn the lamp on.

The A connector is the smaller of the two connectors on the ecu- pull it out of the ecu before starting.
Solder the joint about two inches away from the ecu connector with the battery disconnected, this will make sure no heat gets transferred to the ECU coupling, and that the soldering iron wont put any voltage spikes into the ecu.

Once this is wired in, it should come on when the ignition is turned on and the engine isn't running.

To check for faults turn ignition on, check light should be on, place bridging wire between pins b&c on the diagnosis connector as shown in the wiring diagram. The first time you turn it on it should show no faults as the battery will have been disconnected so the ECU will have lost its' memory.

There is a techo way to set the iac valve duty cycle, but you need a frequency meter. These are is often part of a automotive multi-meter, do you have access to one of those? if not I'll try on the weekend to see if there is a backyard way to work out how open the IAC is.
The hunting you described may be the IAC getting into a surging feedback loop as it keeps trying to manage the idle speed.

I'll see if I can take some pics on the weekend to try and make it clearer.

cheers.

[Taff]

Thanks alot for that, will give it a go wednesday arvo. your instructions will be more than ehough.

[Damo]

Does anyone have the 3 wire type airflow meter?

I have a X-90 motor and it has a 3 wire type airflow meter. I was wondering whether they have the same connector as the Vitara.

[Taff]

only getting error 24 - VSS. its sitting on my desk just have to put it in and wire it up.

check engine is now next to the 4WD light

so I'm going to pull the whole IAC assembly off on the weekend and clean it out.

[Taff]

still running stupidly rich. used 32L over 180km so its sucking it down.

black smoke at idle.

only error code I'm getting is for the VSS.

how do you check a fuel pressure regulator is working correctly?

is it worth getting a new coolant temp sensor for the ECU? is there an easy check for this as well?

[Taff]

Sorted out finally.

turned out to be the inlet side of the AFM was being pinched a little bit by the hose clamp and not letting it spring all the way back.

soooo soo much more responsive off idle now, its not drowning

[nissvit]

fantastic,
great to hear its running at last.

[Scrawny]

Those eyes are slightly disturbing Nissvit

[want33s]

ScrawnC wrote:

Those eyes are slightly disturbing Nissvit

EYES????? I thought it was an invisible strippers bikini top!