No choke/high revs when cold

[Juicy Steve]

Hi all,

I've got a 90 Vitara (as its called in Europe) 1.6i 8v

Recently I've noticed that on turnover I dont get revs up to 2000ish until the engines warm like I used to. It seems to be running a bit lean.

As a result, the engine can struggle a bit until up to temperature. A bit annoying as I live in a really hilly area, and it can stutter accelerating uphill when I leave the house.

I've recently had a refurbed ECU as that died, and a new fuel filter. I also ran injector cleaner through recently just to be sure.

I'm not sure if the injection model has an auto choke or if it was another system causing the high revs, but what ever it was, it isn't now.

Any ideas where I should start looking?! I can't find anyone else with this problem online!

[fixkick]

welcome Steve
that is an old car. with the early TBI single injection and none ECU controlled spark (ECU does fuel only)
Vitara is the correct worldly name. just not here , then.
ok loss of power, (are spark tips black or white?) try new spark plugs yet?
is check engine light on key on, and off running.?
there is no choke on EFI, but the ECU runs many modes of fueling, cold start , cold run, warm run, hot run, and acceleration, and cruise (closed loop)
Cold start is cold rich mode and uses the ECT to tell what the weather is today, if say in Sibera, super super rich, if say in key west florida, tiny rich.
to start.
about 100 times smarter than any choke ever made and is tuned to fuel vapor point specs.
That is why EFI can get 20% better efficiency of any carb car, and more mpg and more power.
One this engine, the distributor (with firewall coil) makes all spark and all ADVANCE the old school way, do a tuneup? cap/rotor, wires, plugs"?

Hi all,

I've got a 90 Vitara (as its called in Europe) 1.6i 8v

Recently I've noticed that on turnover (crank?) I don't get revs up to 2000ish until the engines warm like I used to.
It seems to be running a bit lean.
in not sure what turnover means, here in usa its crank over, starter motor cranking and engine.
some call idling turn over,
it cranks, it turns, it starts, it runs and the ECU sustains idle.

As a result, the engine can struggle a bit until up to temperature. (are you saying cold engine lacks power but hot engine has full power (80hp is full)
?
A bit annoying as I live in a really hilly area, and it can stutter accelerating uphill when I leave the house. that is easy that is called misfire.
but is that a hot or cold engine misfire??????? that dash gauge tells you hot or cold, hot is upper end of scale,
first and foremost does the engine get to 180f water temp and hold. called a normal hot engine, it must or the ECU will go nuts.

I've recently had a refurbed ECU as that died, and a new fuel filter. I also ran injector cleaner through recently just to be sure.

I'm not sure if the injection model has an auto choke or if it was another system causing the high revs, but what ever it was, it isn't now.

Any ideas where I should start looking?! I can't find anyone else with this problem online!

yes the new car , starts, and runs, then the 5 t0 15 second fast idle device races engine real fast 2000?, called the Dashpot, mounted on rear or TB
TB = throttle body with its single injector

then it races about 1500 rpm after the dash pot retracts in seconds.
this 1500 is the RPM caused by the ISC thermal valve in the base of the TB, and is open below 150f water temp.

when the water (coolant) crosses 150F (65c) the valve closes and the ECU takes over idle speeds, using the ISC valve, (2 wires there) and is 800 RPM, is regulated now, in a closed servo way.
the 800, is only with all accessories off, but if some are on, it's 950 rpm? head lights, heater blower, defrost, AC on, etc. (all rpm here are _+50rpm variances)
the 950 is called hot fast idle mode.

ok misfire.
misfire, can be spark related, (or too rich fuel)
or ECU struck in limphome CEL glowing away, ignored or worse a dead CEL LAMP, called backup mode, both are super rich modes, and black spark tips , misfiring and stinking rich smell from exhaust, and if CAT present, it glows cherry red. up hills.

loss of power from misfire is not lean, that is
bogging is lean, and like dragging a dead weight, a smooth dead loss of power,
misfire is violent, and is bad spark or super super rich mixtures.
Super rich can make any spark plug misfire, even new one.s.

that is about it.
keep in mind i need to know engine temps, for all symptoms....


questions in order
1: does the CEL glow keyon (aka, SES or MIL, check engine light) service engine soon, etc. lamp, all are same, regardless of names.
2: when start engine does the CEL go out.?
3: when symptoms happen is engine fully hot, ?

[Juicy Steve]

questions in order
1: does the CEL glow keyon (aka, SES or MIL, check engine light) service engine soon, etc. lamp, all are same, regardless of names.
2: when start engine does the CEL go out.?
3: when symptoms happen is engine fully hot, ?

Thanks for the detailed reply fixkick.

In answer to questions:

1: Yes
2: Yes
3: The symptoms go away after some driving, all though I feel like that the amount of driving is getting longer. Also, symptoms seem to be getting more profound. Used to be a bit of juddering, now it feels like fully cutting out (a bit like running out of petrol) - also, the misfire seems to stop once over 2500rpm.

Going to get the plugs out and take a look when I get chance, been a busy few weeks!

[fixkick]

questions in order
1: does the CEL glow keyon (aka, SES or MIL, check engine light) service engine soon, etc. lamp, all are same, regardless of names.
2: when start engine does the CEL go out.?
3: when symptoms happen is engine fully hot, ?

Thanks for the detailed reply fixkick.

In answer to questions:

1: Yes
2: Yes
3: The symptoms go away after some driving, all though I feel like that the amount of driving is getting longer. Also, symptoms seem to be getting more profound. Used to be a bit of juddering, now it feels like fully cutting out (a bit like running out of petrol) - also, the misfire seems to stop once over 2500rpm.

Going to get the plugs out and take a look when I get chance, been a busy few weeks!

ok , what this is misfire, try new spark plugs/ this is always first thing with misfire.
get the spark good, and then hope for good fueling rates.

the ECU (TBI) on this car 1990 runs fuel only in many cases. in say Europe there are 8 engine classes, 2 block, 2 heads type , TBI, MPI and carb
and some have strand alone distributor, with its own ignitor and vacuum advance.
is yours with vacuum advance, if yes, then the ECU does not DO the spark, , only the distrib and coil do that, with mech, advance too.
later they switched to ECU spark and ECU advance, a big change,
once spark is ok.
one trick is to check spark advance at hot idle, if still timed right good if the came belt slipped, it retards, and the strobe light lands far to the right of spark scale retarded. huge. amounts, or gets worse as it slips more. (a does cylinder compression fall , and keeps falling x4) 170normal 80 on all is belt slipped.

the cam belt is a 100kmeter service. 100km. service point.

once all this is ok, then we work fueling issues.
top item is always, fuel pressure, (keyon 3times pressure then at idle pressure)

our 89/90 has vacuum advance like here.
see these parts."?
see part 11, this is the ignitor that need no ECU to work.
the advancing weights are below the "pickup coil plate" the pickup coil is a VR coil sensor. and is GAPPED, if the gap is wrong, it will misfire.
http://www.fixkick.com/IGN_timing/8v-real/89disty2.jpg

first i need to know exactly what distributor you have.
The above, distrib runs on fuel ONLY ECU.

cheers and good luck !

[Juicy Steve]

Thanks, had a quick look at the HT leads and they are all OK, going to take sparks out later, inspect etc. Do they need a certain torque when replacing?

Think this car doesn't have the ECU control the spark, as when ECU failed, car was still sparking as we checked that first.

Certain cam was replaced just before we purchased, will check receipts.

[Juicy Steve]

Just realised the torque is in that scan, thanks!

[fixkick]

yes the spark plug makers also tell spark torque most show 15ft llbs, max. on new plugs i can acutally feel the hollow spark washers collapse just as you near 15ft/lbs.

if spark timing looks ok maybe the cam is timed right. compression is the only sure fire way to know it is.
the compression is a bench mark at sealevel, and very repeatable.
"My 91' 8 valve, pulls 155 psi. (dead cold at 72F) Suzuki minimum spec for hot coolant is 170 PSI " most do that warm to hot. easy.... g16A
the reading as function of altitude and compression ratio and not displacement. (sure cam profiles but all are same here)
this check at wOT shows the Previous owner did the cam time correctly
then set spark time next,
if both are good then work spark or fueling.


you have vacuum advance there?

[fixkick]

Mine did the opposite: when cold perfect running , after warming up one cylinder was stop working only at low rpm and return ok over 2500 rpm, all of this was caused by defective second cylinder spark plug cable !
the cables never last the live of any engine, made. the are a 60k service point,

Still I can not explain why the cable was ok cold and stop working hot.. (best is not to worry why bad wires are bad but..)
if fails from a process called Entropy. (as in all things do)

sure easy, the stock cables are cheap junk carbon string and low cost insulation. (buy Bosch or NGK mag wire, and go farther, and longer) no kidding.
the carbon core (string) goes bad easy, it gets loose and fractures, and then fails. they all do that. it's cheap wire, (bottom of barrel). after all, and does that,
mag wire don't do that. (not only that, with upscale mag wires the insulation is far better, (read the spec sheets at Bosch or NGK for what and why.)
also most materials expand hot, and that can cause a defect in anything, to get better or worse, depends on the shape ,character and qualities of said defect. (with carbon lots of ways)
Not only that the wire shakes all the time (4 banger do shake a lot), think how carbon likes being beat to death every day, (yes,a hopeless case).
The generation of suzuki does have weak spark to start, its not HEI, yet, that happened in 1999. high energy ignition is not here, that is why the spark gaps are so small. (the some forget to set, too and have bad spark)
cheers and good luck.




The purpose of the wire are 2 fold.
1: capture and deliver the high voltage to the spark plug, for a strong spark. That takes good wire, and good insulation, 2 things.
2: cut radio noise , called RFI. (radio freq. interference) this is the resistance quality. ohms per foot or inductance per/foot if MAG wire.


Greetings

hope helps.
but there are over 50 reasons for misfire. lacking a full 60k mile tuneup is just 1 of them.
the vast ways to misfire. in text... just to show it's not simple. (it is in physics, bad engine, bad spark bad, fueling rates)
even 1 sticking valve stem will cause misfire or from having valve lash wrong, ignored by the owner at THAT step on the 60k mile service points in the operators guide.
or as simple as not setting spark gap, per the hood sticker.. bam misfire. it's really a HUGE list.
http://jeepdied.com/misfire50.txt

[fixkick]

lots of failure modes in wire. (HV, HT) high voltage , high Tension.)
here is one more, insulation .
Insulation when old can act as a sponge,
and when the engine cools , or is a rainy or foggy night
the wires suck up moisture (junk or old wire)
this makes starting it harder and once started, it misfires, until hot and baked dry.
one more common failure of spark wire, endless for 100 years this problem.
if the wire as a water pipe and it leaked water, the owner would see that.
but seening electrons leak is kinda hard, yes you can see some (not all) leakage with eyes adjusted to the dark, and running engine in the dark.
newer better wires have better insulation that doesn't crack and break down at 200f engine heat or fail from vibration.
My guess is the better wires last twice as long, but cost twice as much.
whats best is a owners choice.

[Juicy Steve]

Inspected plugs and cables, looks like original cables from 1990! One plug had a loose nipple, one nipple has sheered off. Managed to fix and its no longer misfiring all the time but occasional splutter so think replacing the lot should fix. They all sparked OK and wires all had readouts on the multimeter but almost certain they are close to end of life.

Apparently here in Spain tune ups don't happen, things just get replaced on death!