All 1.6L  G16a/b  Engine Problems:                                                                                                                  
No Carburetors Covered , sorry!
 If you have a Carb, join the 
Samurai  Forum.           The best Carb path is boiling it out and kit'ing it.

The Jargon not clear?, see here.

Popular engine issues, next.

My 91 2door 4-WD, 5speed got 28mpg on E10 fuel.

Failures, usually happen only 3 ways:  Going out of this order, invites, long wasted effort and hard earned cash.
  A compression gauge is $20, and solves the bad engine idea in about 1 hours work.  150 PSI (wide open throttle) minimum. on all 4 cylinders.

  • Bad Engine ( is the engine really good?) 
  • Bad spark  on any or all cylinders ( this can be , lack of a Tuneup, timed wrong, or a hard random failure)   The word "tuneup" , means, restoring spark, to a factory fresh state.
  • Bad fueling.  (too much or too little fuel)  [can be lack of air too, at idle, in this case it floods or vacuum leaks (lean)]
For 1.8L DOHC Suzuki  Sport engines?  < see here, how it differs from 1.6L.

How you proceed?, depends on TIME, TOOLS and luck, in truth, any of the 3 paths can fail at anytime, no matter what. 
 If confused?, 
see Scotty do it, on youtube. (a very good video)

  1. Got Old Bad fuel ?, found car in  a barn? ! drain it all, flush it and change the fuel filter.
  2. A Bad  Engine, is next, because all else is useless, without it. The  Timing belt slipped?  The Compression test works here !.
  3. Bad  wires to all sensors , 12vdc power wires and to actuators will cause great problems , don't proceed with bad EFI primary wires.
  4. Never doing tune-up's , skip;in 60,000 mile service? Causing bad spark (we check spark timing and advance on all tuneups) BAD SPARK !  Ignition Timing way off?  
  5. No start? , my injectors are dead? ( but runs on test fuel?) Spark is good!  THE NOID LAMP TEST is an easy test here. 
  6. Too Low fuel pressure?  30 is low,  60PSI causes flooding.

  7. EGR stuck wide  open.
  8. CAT melted ,  (the engine is an air pump, if it can't pump air,  it's NOT AN ENGINE); The cat tests is easy. (vaccum gauge in hand)

The below, are all the things that make the engine seem bad:
What is EFI:
EFI , what is it ? (Electronic fuel Injection), how does it work?, and what things can fool it?

This next linked page is just a general page, what should I know before I begin.
My engine acts strange. ( what to do?, fish or cut bait?) DIY or take it to a shop?

A beginning:
Check all fuses first,  for sure "IG-coil" and "FI" (cab box)
Is the Check engine lamp dead? key on only, or stuck on? running. 
Is my ECU hiding a secret, like it knows what is wrong, but I'm not looking, or even asking it?  Why not look here first.? Takes what, 5min?
The CEL lamp is next ! The Check engine lamp. (or service engine soon. SEL lamp.) Mechanics,call it the MIL lamp.
On all cars 1996 (USA) and newer we use a scan tool to see all DTC errors.  First.
Had  a full tune up (60,000 mile) this decade?

A good engine  runs well, if the ECU/PCM  inputs are all good (sensors), and its acuators (Injectors) are working correctly.
One more input the ECU is blind to, is wrong fuel pressures.  If pressures are 10  PSI or 60 PSI this is a big lie to the ECU.
The 8valve TBI Fuel pressure is steady running at one alitiude.
The MPI is dynamic based on engine load (vacuum)  WOT is max fuel pressure, wide open throttle.
The 8valve races with vacuum leaks at full power
and the 16v MPI goes lean with vacuum leaks. (power loss or tip-in throttle power loss)

Is engine stalling or misfiring?

DIAGNOSTICS (ON BOARD)  OBD1 AND 2:  Including the CHECK ENGINE LAMP.  (for A/T , ABS - Brakes, Air bags and Engine)

How to locate and find  parts,  on your engine:  sensors,  idle controllers, solenoids, vacuum bits, etc. or  just  how to Identify your engine?

If working ,with the valve  cover removed, on the engine, do not forget the targets of opportunity.

What is TDC and how to find it , firing orders. Cam and spark , top dead center firing.

Is the ECU BAD? PCM?  The engine brain, can go bad , easy from 1989-95 !  "correct the bad Electrolytic Capacitors, now !"

How to operate the antique and rare OBD1
scan tools.    

How to operate the modern  1996 + OBD2  full scan examples.  (100% supported by all tool makers in the USA) (some countries delayed until 2006)

The dreaded EGR failures,  (4 generations) (stalls at all stop signs? or wont idle at 800 RPM?)

More  Engine issues here.

Engine Torque settings?

FUEL SUPPLY SYSTEM !   Please work fuel parts outdoors, away from all  loved ones, and valuables !
Read all fuel warnings, and please be safe.

Before working fuels systems, Read the below and do not skip the warnings, nor the great tricks and hints.
How  to DE-PRESSURIZE the fuel system? ( SAFETY  first !, please read me !.)

The EFI system is totally useless with , weak or fluctuating fuel pressures.  32 PSI is about par, Or with bad fuel.
A clogged fuel filter will cause this and kills  a perfectly good fuel pump. (it over loads the pump at up to 60psi.)
Did you know a wrong gas cap can cause the fuel pump to fail?  (a missing vacuum breaker, in the cap!)
I know my fuel pump is dead ,  "work out a known pump failure !"

These next checks, find a bad injector (leaks) dead pump or out of control Fuel pressure regulator.
The complete  fuel pressure test page and all related parts tested , spec. pressures and tests for same  

No starts?  with good fuel pressure, check the injectors.  This checks the ECU and all things that cause a dead/bad injector.
How do I  test  my  fuel injectors ?  or       Is my 8v TBI  injector dead   or  what about my 16v MPI injectors?

(EVAP  tank vent systems .)  The DTC can fail for this with a loose gas cap.  If the wrong cap is used ,the fuel tank can collapse.
If the wrong cap is used, the vacuum created in the tank will tall the fuel pump. (low or zero fuel pressure, so drive with cap loose to test this theory)
EVAP Canister (system) malfunctions or the gas tank goes to a hard vacuum? and fuel pump fails? and engine bogs/dies. 


The engine didn't just die (get sick)  today on your daily driver, no,  it's some old barn/field found KICK?, and abandoned old dead dog.

No crank is a dead starter (etc) , the starter won't turn over.  (in the old days we actually hand cranked motors, even old VW beetles came with said crank)

Any engine that can not crank over?,  will never start and run! (unless you push start, or gravity start my M/T  cars)
Try to jumper cable start the car first, just like AAA tow does.  (via a running, other cars battery)
(keep in mind, cranking only happens robustly with a charged battery and a good starter.
(bad batteries, bad charging systems and phantom drains all case bad cranking)
Badly timed spark (advanced too far)  can overload the starter motor . 
(if the spark fires too early?, the engine will try to start backwards, overloading the starter motor)
Begin with the battery fully charged to 12.6vdc rested.

My engine starter motor is silent or clicks only, called NO CRANK.

Bad , dead or intermittent electrical power:   Head lights dead? Dash board, or ECU dead? 
Nothing works right with low electric power.  If head lights fail, troubleshoot that first. They are hot (12v) at all times, keys in pocket too.

My battery will not charge, it's dead now. , what can I do? , it can not crank over a motor, like that !

My Engine will not start and run, but cranks perfectly.

I have no spark , now what? or how to check it.? Please check all 5 HighVoltage, spark wires. (4 wires after 1995)

Logic Rule 1: the ECU will not inject fuel if it thinks (senses) ,there is no spark, or the Tachometer goes dead.  (even if spark is perfect)
The dash tacho needle only moves a tiny bit cranking, no start) and some not at all with weak main battery.
Some cars have no dash tachometer,  but the ECU will set DTC code 41 cranking, if the brown wire is dead or weak.
I use a scope on the Tacho brown wire. If the signal is dead, the ECU WILL CUT FUEL ! BY DESIGN and programming, inside.

Logic Rule 2:  The ECU/PCM ,Will cut all injections if the TPS , TP pin sticks above 3.5v Cranking.(about) this is W.O.T. ECU unflood mode and is  covered in the operators guide (a broken TPS ground wire,  can cause  it)
So will the  loss of CMP (dizzy base) signals, but not CKP (crank sensor) , the engine does run with a dead CKP. 1996+
This  next link, answers all injection loss questions.
My engine, only runs, on Sprayed Test Fuel

My Car was Found, On the  Road, Dead   (or hot soak , non restarts)  < a daily driver  car, died.

My Engine is misfiring , why?  ( or can be flooding , misfire can be too lean, too rich or bad spark)  96'+ cars report this better P030x?

Why is my engine  flooding ?   ( the spark tips are soaking wet are they); It can flood and fail to start.

Limphome  is a  horrible nasty thing the ECU does,   runs  rich , has late timing and eats fuel. Backup mode is even worse. Exhaust glows red? (has a RPM limit too)

Misfire for any reason will cause an engine power loss.  Misfire is also bad Combustion.
Misfire make the engine shack and the 5 speed transmission shifter handle, too.

Power loss :
You never replaced the Timing belt ?, nor corrected the TSB revised torque settings,  at the mandatory 60,000 mile tune up! Ouch, now the crank key is wrecked.

My engine starts & runs , but it has bogging and has power loss?

Why does my engine stall & die  at stop signs , etc .? EGR is #1 fail. (stuck closed ISC, or horrible spark or cam timing)

The next link covers all intake air leaks, be it external or via Bad ISC/IAC. (causing lean out, or racing idle speeds)
Bad  IDLE ?, all ways, too slow, too fast, or will not regulate at 800 RPM hot.

My engine is over heating & dash gauge is  not fibbing.  (I have a IR Pyro gun and it never lies!)
Over heating can cause power loss, pinging and misfire.

Not reading TSB's causes this next THERMOSTAT  issue: 
My Suzuki SideKick engine is an Ice Berg or is like a block of ice. The cab heater is weak, and EFI went totally NUTS !

Bad grounds on this vehicle are  common . See my  ground inspection page. Suzuki's have some very weak grounds.

ENGINE Noises?

Low MPG warns of problems  with the  engine, or very poor fuel economy.  (It only gets 12 mpg?,  what can be wrong?) (answer, FAILSAFE? mode, or worse)

Why , MPG is poor (< 19 MPG)?: (all the reasons)  30 MPG is the EPA high limit.
(USA gallons are not imperial,  the imperial long gallons that are 1.2 times larger)
There is really no lower limit, in the city, but 12 seems to be the record low.  (EPA found 19 MPG was minimum.)  YMMV !

Diagnosis, (just engine)
There are many driving symptoms, and causes, the symptoms are,  mostly noise, misfire , engine power loss, hesitates on acceleration or stalls.
I have a page for each symptom, all listed above.
For sure, tune up the engine first , then check spark timing next.  If spark is ok, then the cam belt did not slip.

Fueling checks are complex:
The fuel pressures are checked first if fueling is bad (scan too shows no DTC errors)
I also check the Fuel pump regulator next.
The ECU will not inject properly if the regulator is bad in any way, including leaking fuel to the vacuum hose.
The injectors must pass the injector balance test.
The ECU will also inject fuel wrong if the ECT is out spec. (reads wrong)  See testing sensors.     more sensor facts here.
The same is true of the MPI MAF or the TBI MAP SENSORS.
The O2 sensor (front) need to be replaced near 100,000 miles. for best fueling and economy.
The links above cover every sensor on car, and all actuators.  (spec.'s and simple tests for each device)

Happy Trials

ver 10