air intake (heated vs non-heated) and IAC bypass

[kthnos]

welcome!

wow, wow and again wow!

first things first, THANKS a bunch for your time and effort in helping me. You're Welcome !

i bought this car used in a bad shape and have done many things to tune it up (with very good success so far i think).

now, lets cut to the chase:

1.at +15Celcius,(59F, is this air or coolant temps") -> i think its both since its cold start at the morning. coolant temp = ~air temp.
you think that an engine racing at 2300rpm is normal? because that's what mine did (it has ~200k miles on it) before i PARTIALLY blocked the IAC. now it cold starts at ~1500rpm rather than ~2300rpm.
you blocked, the IAC thermal or IAC electric (ISC)???????????
the answer is 2300 is not normal at 15c Air temps. it's too fast. 1500 is normal and drops quicking and then totally as the IAC (thermal closes at 65C)
too fast idle cold and how ma

-> i blocked the thermal IAC PARTIALLY (not fully!) a little bit every time untill i got ~1500rpm cold starts (which i deem as 'normal'). i think my IAC pellet has gone loose over time (200k miles is no small number i guess).


2.regarding the 'rich event':
happened every time before i lied via the ECT.
i could tell by my...nose! i literally could smell unburnt fuel on cold starts for a few minutes.
The cold CAT and cold engines, all make that smell due to the cold Air fuel mixture tables of the ECU.
usually you'd have to walk to rear of car, get nose next to end of tail pipe to notices this. (unless the wind blow it to the cab)
-> i guess i have a flimsy nose then because i could tell from 10m away...



this effect was drastically reduced once i used that 2k ohm resistor. what it does (i know you know this already ),
is it makes the ECU think its about 35C instead of 15C. (300 ohms is hot engine, and ECU exits cold start mode then exits warm start mode)
when on operating temps (85C),
the difference between reality and ECT reporting temperature is minor to negligible (non-linear thermistor it is).

3.the reason i added the resistor is because i partially blocked the IAC (to compensate for the less air allowed). i am not sure (i need your input on this) what the ECU does in open-loop; especially on cold-starts. does it inject based on MAF input and ECT readings only?
True: the maf works all the time, and is not all that accurate at low rpms, but cold starts are about 1500 rpm and maf works great there.
once engine warms and idle drops to 800 (IAC thermal closed 100% ) the 02 enters closed loop mode.. and now corrects MAF errors, (and some ECT)
this engine has no MAP sensor, so measures Air flows, direct (mass air flow senso)
-> in that case, since i get ~1500rpm cold idle (now, after what i `ve done), i guess its fine then? whats your opinion? am i getting too lean at cold startup with that 2k resistor?

if yes, then why blocking (completely) the IAC?(which one) makes the engine go rich? (since IAC is legal induction -MAF monitored). shouldn`t the ECU compensate automatically for a blocked IAC and spray less fuel? (sure but maybe not correctly)
great questions , when engine is in cold start mode (ECU) the ecu is not in closed loop. but is in TABLE mode.
the ECU looks up the temp then the maf reading , using the 2 axis table , finds which injector pulses are need, for regular petrol fuse , cold manifold, and engine, the tables go richer colder and are match for the PETROL spec.. on vaporization at all temps even to -40C. super rich there. crazy rich. there..
cold fuel does not vaporize, the tables are FUEL vapor tables. and are amazingly accurate, unlike any carb choke ever made.
and compensates for altitude too, EFI.
i think you are over working the problem. sorry, I which i know what your are troubleshooting. just sniff, or just 2300 or ??????
best is not to fool the ECU, make sure inputs are correct. first. (measure inputs)
wish i knew which IAC you blocked,? (both can be blocked) but which one, best is to called the wired IAC the ISC, for clarity.

-> i would NEVER block the ISC my friend. i am not that dumb plus, want idle controls on ECU when hot

4.yes, my injectors are the next thing i need to look upon. along with the FPR and valve lash. i have already ordered a gauge with an adapter to fit on the fuel rail line and check what the FPR (and fuel pump) is up to.
my injectors look like nippon-denso "ND" brand and (desperately i think) could use some cleaning.
just need to find some facility that does injectors in my area (not too easy). id just use the fuel pressure meter to test them.
The only risk is if all 4 are equally partially clogged, the all seem good, but most times one is bad. dead, weak or leaking. and bam you find that in the balance test. In not remove injectors if the tests pass, on my pump page. id not.
if the engine power is lacking at WOT, then id have the injector cleaned. lacking the full 95hp at fly wheel.
the balance test finds most of all the failure modes, (my 7 tests on my pump page and if from FSM too, id didnt invent it)
if those pass, it take 4 partial clogged injectors to fool, me and the full power of engine would be weak.
-> i think thats the case (weak WOT) with mine, but i can`t be sure. but i will work it out one way (pump & FPR) or the other (injectors).

5.my IAC closes completely right at 155F (measured with IR gun). GOOD, very near all mine. and is SPEC
what is HOt RPM, what is HOT ISC dutycycle, does the hot 800 rpm regulate? when you turn on head lights and blower? and hold 800rpm is this car a stick or auto trans?
-> its 5spd manual transmission. headlights and blower are not regulated via ISC i think. only power steering and AC. ~850rpm on hot idle always, unless i switch on the AC; then it jumps to 1000-1100rpm. endpoints on power steering also create an ISC compensation from what i can tell. i can even hear the ISC ticking then
i had issues on HOT restart. interminent hot idle was 500rpm sometimes. didn`t happen again since i replaced the EGR. i think/believe that the spring on the old one was sticking sometimes causing it to not shut the diaphragm completely (one more piece of evidence was slight/audible pinging at idle when this happened).


my thermostat is genuine suzuki 82C with CORRECT gasket ring (and some RTV ). works like a charm. goes to operating temp within 3-5 minutes. upper rad hose doesn`t even get hot before thermostat goes to ~82C. very few thermal losses there. stock clutch fan discarded, SPAL 16" fan attached. fan switch (via relay to the fan) placed at top rad hose and opens at 90C (where the thermostat is almost wide open and the rad has gone hot -even down to the bottom). cluster temp gauge gets slightly above medium before fan kicks in and falls slight below medium when fan shuts off (~84C). fan never comes on even when cruising as slow as 40km/h (about 25mph). whole cooling system has been flushed 5 times within a week and fresh 50/50 coolant was filled. all gunk,debris and rust is out and gone. all large hoses are new.
(all that is normal and prefect)


6. spark plugs (NGK iridium) )GAPPED to .70 mm?, spark wires (Beru), dizzy cap and rotor (Bosch),
this car has weak spark, do not run surface gap plugs, 2j,3j or 4j plugs run Iridium 1J gapped right, and its happy,
-> i will check my spark plugs box (don`t remember exactly the code now) and let you know. but i didn`t gape them at all.
cluster temp sender, radiator, heater core, hoses, thermostat, water pump, timing belt, suspension springs, shock absorbers, wheels & tires, and lots of other (smaller) bits were replaced with new ones, along with a complete brakes overhaul and lots of bodywork and painting.

what remains is transmission rebuilding (noise when neutral and on 3rd gear;must be a bad bearing(s) or worse), injectors`clean-up, FPR, and valve lash check-up. i also need to check that 17mm bolt on camshaft (do i even spell this properly?).

vsig: year,G16B with 5speed sticK?, doors count? , 4wd or 2wd?
photo of engine? post it?
-> check my signature its G16BS with stick, 4wd, 5door.

the G16b comes in many forms world wide,
different EGR
different intake manifold
some even have unique IAC /IsC s parts. (our IAC is under the throttle body bolted there) our ISC is on the front left plenum box and has only 2 wires)
be nice to see your engine, near the throttle body.
-> thats exactly how mine is. check attached photo.

The 2300 prm cold start(if dash tacho is not fibbing) is too high for 60c starts (ambient and coolant temps)
most G16b the dash tacho, 1 line (1000) the idle is a hair above the 1 line. the dash tach is TOY GRADE ,and when old they lie. more.
i never trust it until i validate it with real tools (obd data) or hand laser tacho.(dead accurate)
-> i used a strobe light (when i adjusted spark advance). my tach reads ~100rpm lower than actual (actual=what the strobe light said and i trust it because it reads pulses on spark plug wire).

if you block and air path, i'd need to know where. exactly. (suzuki changes parts names 3 times, so......)
you smell gas at cold start, maybe when you shut if off last, then one injector leaked down, all fuel drained there, and rail goes to 0psi.
then you start it later and sure it will be full of HC.(black smoke)

the injector leak down test is first. always if cold starts seem wrong.
it must hold for 1 minute, 25psi key'd off (test 3)
http://www.fixkick.com/INJECTORS/pump.html
fuel pressure must be in spec,
the FPR most work right keyon, idle and W.oT or the ecu will inject wrong.
-> will do immediately once i receive the fuel pressure gauge and adapter that i have ordered. i will fit it on the fuel rail bolt. your site helped immensely on this!

what is the ect ohms at 60c, see my ECT page? "unplugged" 580 ohms is SPEC. what is yours.
http://www.fixkick.com/ECU/temp-sensors.html
what is maf voltage key on no start.
and then at hot idle?
-> never measured the MAF, but i will do it if you think that i have to. ECT is spot on at ~260ohms @~85C.

the only hard tests are the INJ balance test. the 9v battery test is safe, i think, (lacking a real pulser tool)

when the FPR vac. hose is removed, does the nipple leak fuel, yes= bad FPR
-> thats an easy test. will do tonight!

more tests>?
sure
what is rpm HOT, engine, with the ISC hose pinched,(2 water are hot, 1 cold air hose, pinched.)
most do 400 rpm or even stalls.
-> mine is crumbling at ~300-350rpm when i do that.

this finds illegal air leaks,
or some one played with the idle duty screws (x2) or the TV stop screw VIOLATED by the unknowing.....
on our cars the old ISC internal rubber seat gets old and ugly and leaks air .. and can be cured, ask)

you have a scan tooL?
->no, but i will get one. i love wrenching this car!

---

keep in mind I cant hear or see ,feel or drive car.
is engine misfiring,shaking or making odd sounds from dead cold or hot or driving?
-> heavy shaking for about 2 seconds ONLY when cold starting ONLY on COLD winter mornings (+5Celcius) ONLY after i added the resistor

got nice mag. spark wires, BOSCH mag,or NGK, is best. they last for a very long time and help make up for weak, spark, this EFI has.
mag is not carbon, not silicon, its coiled wire inside that are Conductors.
is the rear exhaust manifold tube cracked, as many do.? this has tin skins there, that must be removed to see this crack.
-> my exhaust gasket was leaking and i got i replaced. didn`t notice any (visible) cracks on the exhaust manifold. catalyst however may be EOL since it was never replaced. i guess a smog test will see that (soon to be done).

the FPR page is here, btw. overkill the on car tests are easy and enough.

http://www.fixkick.com/sensors/tests/FPress-reg1.html

what is hot rpm
is the CEL lamp glowing running'
if have scan tool and DTCs and are all sensor working
and is closed loop working hot.
is MPG ok>? petro/ per 100km.
-> constantly around ~8.7L/100km and thats ALL with short city trips (5km) so the engine just reaches operating temp by the time i switch off the car.
no CEL problems (i had issues when i got the car with VSS and Oxygen, but i sorted these out for good).