Motor cranks, but you suspect fuel injection problems?
No start,
for Dummies
(Just 1 page for , No starts)
This page assumes car was running not long ago. (gas is good,
battery is charged ,etc) for other
No Starts look here. For NO Crank, look here.
The order below, is by , most likely to fail and proper order.
(3)
The
format here, is to find which sub-system is failing quickly..
(bad
motor, bad spark, or bad fueling , in that order !)
Nothings changed since
1861 Nikolaus Otto first motor ; The Same 3 fail modes.
Each line below is "if above was ok"
If you error in your testing and get nowhere, then start again at the
top and do the tests over. A Typical motor.
Preconditions: CEL
comes on KEY ON, and flashes 12 with diagnostic jumper or fuse or
wire is inserted into the DLC (pre96') , or the Scan tool
shows no stored and
valid DTCs.(1996 and newer cars, USA)
A tuned up car is
ALWAYS assumed. FIRST ! CHECK ALL FUSES FIRST
( do not look at them,measure them , looking misses cracks , use an ohm
meter or battery power test light.)
If the Head lamps are
dead, or Cig lighter, or other major power loss symptoms? , fix THAT first.
The order below is based on the 3 bad's in
red above
and in order of easy to harder testing. This page can not be perfect as
there are 2 engines and missing dash Tachometers. but here is my
shot, at a 1 page list (printable)
Bad motor is the first test "compression", but I put it at
step 8 due to harder to do. NO
TOOLS ? NO JOY ! ONLY FATE dictates TRUTH. My list assumes you
can spend $50 on tools.
Really, step 25 is first. (the tachmeter check) (2wd don't
have a tacho meter in dash,. so ..... us a scope ? look for code
DTC41s?) (6)
The 8v is unique, if I look and
see my TBI injector is dead, out comes the NOID and step 25 is checked.
- No spark? check spark
at each spark plug and at the
Induction coil its self (below 96 year) [96 is first year of
Coil in Distributor.] If 1.8L or bigger check at each
COP COIL.
- Did you know, that a $15
timing stobe lamp
can check to see if timing is near 5degree's before TDC, in 5min flat
off spark wire 1 (front)? and if way off, the timing belt
slipped, (forgot the 60k mile service you did !)
- Check for, if spark plug tips are wet or dry.
? (if the spark wells are flooded with oil {shorting out
the plug} a new valve-cover gasket must replaced, 60k skipped x2} A new spark plug the tip is dry
and white/tan
- If wet , unflood motor
using OP GUIDE secret WOT unflood mode.
Crank engine with throttle foot wide-open-throttle. this "WOT" )
act
kills all fuel injections cranking. . Unflood trick 1.
- If all sparks are wet check Ignition
timing , if
way off Check Cam timing (look down oil filler hole ?see if cam spins
cranking?)
- If
the 16v MPI engine has 1 wet spark plug (good spark) ,stinking of
raw fuel suspect a leaky injector problem, The 8v TBI you can
look at the Injector to see if it leaks, at just key off, or is not
injecting at all. cranking?
- If dry , then
try test fuel
, I use an instant start spray can test
fuel , attach the straw and put
straw in the EVAP VSV
nipple of the front plenum chamber.(nipple #21) hose off
- If dry, at spark plugs , & motor dont start with
test fuel, then you need to
check compression on the motor. 170 PSI HOT on all 4 , minimum
and at W.O.T. (wide open throttle) a
tad less cold.
- IF test fuel passes and motor sounded strong, as it
spun up fast, then down and died, then the motor
is probably good.
If not, a compression test is mandatory. If all 4 cyl. are low PSI, the Tbelt slipped.
(<=90 psi is bad, 150 or more is good)
- If motor sounds good, see if fuel pump is
active , by listening at tank filler cap,
as someone else keys on the
ignition. The pump will buzz, 1991-98 for 3 seconds only
each key on. (1) < these are
foot notes !
- If the pump don't buzz check
the power feed to pump, If the
pump does buzz ? open hood & pinch fuel return line at FPregulator , feeling
for swelling, at key on for 3 seconds (1). (16v is hard to do
this)
- If no swell cranking, or can't reach it,, remove the
fuel return line at FPreg and attached a
spare hose to the FPreg
nipple and other end to a bucket (coffee can)
and key on for 3 seconds and see if it squirts briskly.(1) (5)
- If the hose don't squirt, than that
buzzing pump is
dead. any flow at all really tells little about pressure on the
rail , only fuel pressure
tells the truth of this test. (you need near 30PSI to run EFI at
all times)
- If
some fuel squirts , this don't mean much, as only the real 30 PSI
pressure,
can run a engine proper. (30 psi running) , now is the time to use a real fuel gage. and that fails check
for 12vdc at the pump.
- Many DIY don't have a $20 fuel pressure gauge (from HF) so
skip to NOID tests first (a $1 tool) if this is you then do the
injector coil ohms test, ($15 tool) and the NOID. below.
- We have good fuel pressure and now,
so we attack the Injector(s)
, on the 16v (only), one side of the injector is at 12vdc wtih
the key ON, The ECU grounds the other side , to inject. (2)
- While
the fuel pressure gage is attached , check to see if pressure holds to
25psi after the key is released., if it don't, the Injector(s) are
leaking. ( or other things are bad.. for sure !)
- If you suspect dead injectors or
leaking ones. The above leak down, finds the leaker's.
The next test is key
on, and make sure each injector has 12vdc on both sides of each
injector. (16v only) (never 8v)
- If the hot side (16v) is 12.5vdc then all injectors must be
12.5v on all pins. (8 pins total) If not the ECU is bad or the
injector wires
are bad. (measure to ground with Volt meter) (16v only) (8v requires a NOID
light or DSO test)
- If this test
above passes or fails , check that each injector has about 10
ohms, at its
coil pins (unplugged). if open, then injector is not serviceable.
(8valve coil is 1ohm)
(do this key off, all injector(s) unplugged)
- If this test passes,
connect a NOID lamp to each injector, key
on only, and all NOIDs must not be
glowing !, (4)
If any glow it's a bad ECU or wires. (works for 8v and 16v) Full set of NOID
- No glow, then crank
and all NOID's will flash (test one at time, 16v)
they may seem to
stay lighted equally cranking (a strong battery) across each injector,1
to 4 . The single The 8v
looks like this.
- You
can listen to each injector for clicking, during cranking. No clicks
can be a bad injector , bad ECU or bad wires to same.
(stethoscope works easy , a $5 tool, the best tool as always is
DSO)
- If the NOID is dead (16v: only one dead, that is a bad ecu
or bad wires between ) if the TBI NOID tests fails that is a BAD ECU or
the 2 inputs are failing. (A1 pin, or TPS pin B stuck high , <=2v is
good, near 4v is bad)
- If the Dash I/P cluster tachometer is dead, there will be
no injection. This guage dead, means Pin A1(8v) or A8(16v) are
dead ! Fix this first, do not replace the ECU if this
fails. (6) (6a)
- The ECU Throws, 41 DTC or dead OBD2 RPM on 96+
cars) Do not replace any ECU if you see, DTC 41/42 cranking for 3 -5
seconds or in new 96+ cars, see the OBD2 scanner with P0340s or RPM
stuck at zero cranking.
- If all tests pass,
good motor, good spark and NOID passes , injector coil ohms good., and
Fuel pressure passes, then you have a
bad INJECTOR.
- If you have not found the injector problem yet, then send
them to witchhunter.com
$19 for test , clean and balance. NO, don't buy a new
set of injectors, they can be serviced if the coils are not open.
(great hope)
Notes:
(1): On 89/90 Sidekicks
the pump is only on
during cranking and this is also true on some 1.8L (unless ECU flash
updated? See TSB on topic. ) Buzzing is no proof at ALL, of
34 PSI pressure !
(2): The 8v motor , the ECU Injector
drivers drive both ground and 12vdc from inside the ECU. via 2
wires. Totally different than an 16v motor ! Do not confuse 8v
and 16v, vast differences.
(3): Feel free to do the tests in any order, if you lack tools , you
will not get far, but trying the test fuel
on any dry spark plug motor, is a good ploy, as is the pump buzz and
pinch test.
(4) At real low RPM, the NOID will flash , at higher RPM cranking
the NOID will seem to be on, all the time cranking only , like this.
(5) the hose pinch tests or squirt test only proves the pump is
dead (or FPreg stuck closed) and never proves a proper pump pressure test.
Do
not forget, that the 8v motor, you can look down the Air horn of
the TB and see it inject (use a flash light ) cranking or see it
leak key on not cranking (bad)
This page assumes the motor is good, mostly and
that the cam is spinning (look) and that the motor is timed (all)
and that the crank bolt is at TSB spec. of 94/ft/lbs
(and crank key is not stripped)
If you have not done your 60K tuneup, why wait ( 60k and all multiples
of this)?
(6) You need to connect the Diagnostic jumper and crank the motor for
3-5seconds release the key ,(dont turn off the key) and see if codes
41/42 show up. if yes?, you found why injection is dead.
(6a:) I you have a 1996+ newer car, connect the scan tool and do
the 5 sec. crank and look for dead RPM? =0 or P0335 or P0340s. if
yes, bingo bad CMP or bad spark. The Tacho must not be dead on this car
too.
Here is witchhunter flow
performance on my 8v injector.(actual)
The
16v 1.6L flow rates are
172cc @ 3 bar.
UnFlooding Trick 2: Pull the fuel
pump relay, dry out those fuel soaked spark plugs, now use
test
fuel if too dry . Put sparks back. Then crank. I unplug the large
plug behind rear left tale light (pump is pink wire)
If motor starts, and sounds good, as it spins to a stops ,
you need
to find why the motor floods (test fuel pressure now ! and leak down
test.)
FAQ: (USA centric on
history, as always...)
Q1: Who or what device, makes my injector(s) FIRE?
A1: The ECU, the ECU IS REALLY THE INJECTION BRAIN. In fact, Suzuki parts list calls it the Fuel Injection controller. It
has injector drivers that he brain modulates to feed fuel rates under
ALL CONDITIONS.
Q2: Who or what device, makes spark?
A1: On 89/90 the Distributor
does that, all by its lonesome. Starting In 91, the ECU now, is
the spark generator and the distributor is only a drummer boy
and
spark distribution device. The ECU actually runs the coil directly
91'+. and CREATES advance.
Q1: What things can kill injection.?
A1:
The loss of spark, the loss of fuel pressure., a bad TPS signaling WOT
all the time (unflood mode forever). , The spark suppressor missing or
open., a bad ECU, clogged or dead injector(s), broken wires to
injectors. , YES, A DEAD TACHOMETER.
My Jargon page: (short)
I assume here, that the
engine
harness wires are connected at the engine or ECU, or all
sensors & actuators are connected) I assume all parts
are in there places. and fresh gasoline (Petrol)
That all sensors wires look good at the sensor ends and at the ECU
side. No hacks, no cut wires, frayed ends.
This page is condensed. and that is its primary purpose. 1 page +
1 liners. For all the reasons for
engine failure look here.
For all nostart reasons
try this page;
versiion 6 12-1-2012
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