good morning !
Hot idle is ISC, cold idle is IAC. ISC is electric air controlled by ECU, IAC is thermal only. (water heated)
ISC , is the idle speed controller, it will work if cleaned, and the idle switch is closed on the throttle TPS (throttle position sensor)
Does the engine have full power hot>?
The other car has lost of engine parts they are the same engine, cept some minor parts (EGR(mightbe) and IAT missing on 92s)
Does the CEL lamp come on key on, and then go out , running? if not pull the flash codes with the jumper paper clip trick.
Does the 94 have a CAT converter still installed , & is that front of cat pipe , present in front of pipe, sill leak free,? 90degree pipe.
there are 2 exhaust manifold, CALif and FED, the long pipe manifold has no 90deg, leaker pipe. The 94 does not have this part.
the 92,pipe of horror. (insides collapse)
http://www.fixkick.com/exhaust/sc01-exh92.pdf
i mention this, because, many of these old cars have engine swaps.. very common practices, this old.
Leak to the rear of this CAT are only a safety issue, not engine tune effecting. This car has only 1 oxygen sensor , up font on the exhaust manifold
the first check on the engine besides the CEL check should be, does my engine get fully hot test. (the dash gauge (temp) helps a bit here, but is better to feel the top hose of the
radiator for 1second, if hand flies off, ouch it is fully hot. (i use an IR pyro gut of this test) 180F is normal temp hot, and is step 1 to good MPG.
if the engine don't idle right
dead cold that means the IAC is stuck closed, this is the device bolted to the bottom of the throttle body.
IAC photos: (idle air controller (cold)
http://www.fixkick.com/fresh-air/Slide_S...ge_23.html
the bolts on the
IAC love to snap off, on removal , so better, is to swap the whole throttle body.
My guess, so for, for cold idle not racing near 1500 on a cold morning is the IAC is stuck closed, bad. (cant be fixed cleaning)
A dead IAC, invites, flooding unless 10% throttle is added, at each cold start.
Once the engine is hot 180F. the ISC takes over idle controls.
other reasons for very
low cold start , idle RPM
1: distributor timing way retarded. (a timing light is needed to check it) $20
2: lean air fuel mixtures, due to clogged injectors, try some injector cleaner . Chevron Techron has benzene and is powerful cleaner. ( i dont think so...)
3: low engine compression, very low, due most likely a
slipped cam timing belt. (all 4 very low, not all 4 at 150 + PSI)
4: intake air leaks cause racing (means too high idle) but on a hot engine air leaks, cause bogging, unless hard right foot is apples to throttle. (it's not this)
5: low fuel pressure but that would make hot full engine power, very weak. (going up hills very hard)
6: in bad need of a tuneup. weak spark, clogged filters.
7:
EGR valve stuck wide open, (seems they all do that ever 50,000 miles.... per Suzuki. and real experience. kills idle hot or cold.
testing the IAC on the car is near impossible task, i can test them, if they leak but not stuck closed.
the hard part is trying to blow thru this slot hole here, iac-input-port.
![[Image: 16v-MPI-Body1w.jpg]](http://www.fixkick.com/fresh-air/Slide_Show/images/16v-MPI-Body1w.jpg)
tell me all about hot engine performance? , driving. all the good , bad and ugly, (so far poor
mpg) 20 is ok, in snow/ice in 4wd. 28 is best on high way 2wd.
does the engine
shake, at idle hot or cold?
cheers to you and family ! Happy trails....
