code 51, 4th exhaust path

[xxx]

500 RPM is a hard, fail... (logic works many a ways, with so many symptoms.)
all you do is clean it, make it closed, and defeat it for testing, for now. (yes plug tube to it or it sucks air and 16v goes lean if that happens)

then open (CCW) the idle air bleed screw on the rear of the TB? can you get 800 now? HOT
yes, good?
no , big time problems.?
as you may know the 16v has 4 injectors that added 4 x all failure modes to the car.
quadruped troubles. (leaks , cogs, sticking ,etc) see my injector page for all tests there.

the 02, can fail in many a way, and only a scope can see all ways! (95)
Symptoms? all?
bad idle ,yes,
bad mpg , yes.
i bet misfiring
I bet some power loss.
does it have full power WOT? ?

the 500 rpm is show stopping hard fail, find out why.?
I make sure my timing is correct with timing freeze jumper,
if the timing is retarded, 500 is the results. so......
compression good, check
spark good, fresh tuneup, timing right, and spark tips not fouling, are the?
all 4, always look at all 4 due to MPI injections.

that's all good. above? we then check fueling after spark tip check.
evidence, gather evidence.
tips black.?
tips white. ?
EGR is closed and DEFEATED, (so easy to do and makes diagnosis vastly more easy)

i then check the 02 for all these things, (you can't do all with a DMM) sorry .
1: stuck low
2: stuck high (not to mention, shifted.)
3: not swinging
4: swinging too slow (you cant do thatwith dmm) and all slow 02s waste fuel.
5: biased. (no man can do that. replace it) (it lies, it fibs, its poisoned )

im listing all ways, and all tests here, so if one is already done above ignore my mention of it.. Im blind and cant see car, the tests or missed symptoms......

The EGR IS just a valve.
pretend it your lawn sprinkler is stuck on.
you remove it and its stuck open, you clean it and now it is not.( lets move on?)
Get EGR MAIN, to close(and keep it there)

ever flex one (egrmain) on car?, i can flex it cold and tell you in 1 second, yes, it closed.
flex thump, flex thumb, flex hang, bad.
keep in mind the bad gasket here is going to leak air. very bad that. bad to bone.
one guy failed to even notice the EGR main was cracked, after 100 posts
he photos it and everyone laughs, gee fella. it's cracked casing. see my paper bag.....?
my point is, get it closed, i flex it and it goes THUNK, ok it's closed.
i then defeat it and fix that bad idle. an all OTHER SYMPTOMS NOW.
that idle is crying for help...... !
and if the o2 dont swing, that is YELLING for help. (at idle and cruise)
if running lean the ISC loses control
heck the ISC can sticking,,,, ever do the test on that?
you go factory air, im blind , do you, yes, turn on the A/c the button turns green
if fan off zero. and the AC clutch kicks in and the ECU see IDLE up command
the ECU then over drives the ISC and idle goes to 1000 rpm
or rises 200 rpm, does yours?
your ect at 300 ohms hot , is good, a scan tools would show that in 1 second flat.
these posts get long only for that fact, no scan tool.
if we had that, id bet we'd see.
02 railed
and no closed loop
and LTFT stuck way off near or at the rails, 95 has excess rail hitting abilities.
corrected in 1996.
so can go like 60% rich,
LTFT is very accurate if you install a fresh 02.
i always do that on any old car.
i do that so my scan tool can see the truth. (a key stone sensor)


is your 02 heater drawing 1amp> at least. 12v into i think 12ohms (IIRC its on my 02 pages)
i told you the ECU has no heater monitor, so that job is the mechanics.

50 UK pounds for a scan tool.

i connect the tool
and see allsensors
i see RPM too low (if fix that )
i see closed loop. not happening at idle
i find o2 heater dead as doornail.
or
i find exh leak near 02
or i find air leaks amany from intake valves all the way to the maf.
or
i see maf is weak and the 02 can no compensate for this gross weakness.

see?
see my looking at the EFI and motor as one systems?


is your car a 4 port egr or mono port.
the mono port has the SST sidewinder tube on the right side plenum box.
the 4 ports are a major PIA to get cleaned.
but for now ignore all that. defeat the EGR and fix all other issues.
then when it runs good, get mr. EGR back on line. last.
EGR means cool longer lasting exhaust valves.

is this too much info.?
yes.
then defeat the EGR (closes ) and fix that idle.
my bad idle page covers that well.

bad idle and misfiring are the most complex of topics
I got a bad idle , cold or hot engine!

[xxx]

counter point, 51s and limp home, i dont think 95 do that , with right ECU,p/n
but that is all moot, why?
because i can start the car and see if O2 goes to closed loop fast (mine does it in 15 sec) the o2 heater allows that mAGIC !
as motor reaches 180F (ECT near 300 ohms) the 02 is in closes loop. IT MUST BE !
There is no code 51s parked, and at idle. so no limphome, no DTCs. no way. at idle, so check LTFT here and 02 actions.

then, with it at closed loop, (and diagnostic jumper planted, you can drive with it planted for weeks)
as you race it, CL drops (at accel) and comes back at below:
you race the engine at 180F to 2500RPM, and steady throttle.
12s flashing over and over. NO DTC'S !
and the 02 either holds closed loop or not. it's that simple, if not BINGO fix that...

EGR is defeated, the ECU has yet to run the monitor. see? no code 51 yet.
anyone can do that..
on a 96 you need to be moving, so EGR is dead not moving.(at any rpm)
on 95 the EGR test , will trigger and take awhile after ,as you move off idle.. (in 96 the seconds delay is in the FSM)

and like i said, a 10,000 resistor in place of the thermprobe, kills 51s for ever.
so you have that trick too.

after EFI is working (yours is not)
you fix EGR
and that
is here.
http://www.fixkick.com/EGR-Gen2a.html


i might add 1 more point
if the EGR leaks, say at idle, the ecu will lose control of AFR.
RPM drops to near 400 rpm (if done by hand) stall test.
but may case the ecu to go to limphome,
the ecu drops to limphome for many stated reasons.
The ecu if it loses control of fuel, it can go to limphome to save the earth from NOX. pollution, (if the ecu thinks the engine is lean, it may do that on
some early years, in 96 they had a design goal of reducing the effects of limphome, (less rich) HC reductions...

there may be a LTFT lean rail trip point, and ecu goes to limphome... i dont know, but it is something to consider
best is to watch the 02 and the LTFT. like a hawk.


96 list is revealing ( the 95 list is shorter)
MAF = P0102/103
IAT = P0112/113
ECT = P0117/118
TPS = P112/123
VSS1 = P0500 ( speedo vss)
TR = P0705 (A/T Range shifter output in conflict)
VSS2 = P0720 ( 4sp Vss tail speed sensor dead)
SS#1 = P0753 (shift solenoid 1 bad)
SS#2 = P0758 (shift solenoid 2 bad)
TCC = P0743 (torque converter clutch issues)

[Swansen]

Thank you for all the info, im still going to look around, make sure everything is in order, i had been on the road for some time so it'd be a good idea to check over everything well. You have also influenced me to get a scanner(or that neat USB alternative). Friend has a really nice snap-on unit, I should see if it will read OBDI, never looked before.

Quick update, idle is normal again(750). As it turn out, unmetered air will give a lean condition every time. At some point over the road, the freezer plug blew out of the EGR, and the valve had a sticky spot, before i took it off, i pushed on the diaphram and it was stuck almost completely open.

In the meantime i just have all passages blocked by plates, but that giant whole in the EGR, in conjunction with that valve sticking was probably causing a lot of the issues, but ill keep looking around.

[xxx]

snap-on don't support pre 96 suzuki's (even after spending $10,000 )
suzuki never released the protocol, so no after market support,.here in usa.
one more reason why chapter 11, IMO.?

there is only one tool that works. on any 95. (in UK)
be alert to false advertisements. read the manuals., it don't list your car.!! none do... (no top brands of any kind or make, no OTC over the counter tools support your car....)
nor can any Auto-store in town do it.... non ! save your gas.
i've read everyone's PDF, (all brands, you name it)

when they say "supports all these cars" bla bla,,, they MEAN 96+ (usa) 98+ Canada
other cars, sure, Suzuki, NO. (the suzuki EFI ugly duckling. in this realm.)

freezer plug blew out of the EGR?

the valve must not leak exhaust from left to right.
it must not leak air. (from atmosphere inward)
the 16v is MAF based, and all air leaks are Verboten, end to end....
fact2 your
EFI ECu will throw 51s, if the EGR is not working.
or
if you fail to put in the liar, resistor (10kohms)
id not run it with out the resistor , if defeating the EGR.
not me. (its software ,why temp fate? )

MPG low ?(motor caused)

• closed EGR
• 10,000 ohm resistor added to appease ECU. (just for testing)
• fuel pressure at 40PSI key on and 30 after start (pump good,fpreg good)
• injectors not leaking or clogged ( 4 or more tests )
• 02 good (swings proper.)
• 02 heater working and drawing 1amp at least.
• 02 holding closed loop at idle and steady cruise.

[xxx]

yes, the freeze plug.
when the valve is 1/2 dirty , and with rich running and short trips.
water from combustion can pack up in there, then winter freeze , freezes this water.
and the welsh plug pops out.
or worse. freeze damage can be limitless..

id bet your motor never hits closed loop
that is my guess... they sell gauges that allow you to see that.

here is a DIY
you can buy them ready made.
a wideband is way more expensive.. meter, weld in bung, sensors, and all....
you can drive and see at all times, if the EFI system is holding closed loop,. if it is, MPG just happens.

http://www.scirocco.org/tech/misc/afgauge/af.html

[Swansen]

quick update, after a really good drive, i checked ECT resistance and it was 400omhs. borrowed an instant read probe thermometer and put it against the block and in coolant/radiator and it was reading 170.

[xxx]

pretty close seems good.
i work spark timing and compression , if those are spec. out. ok.?
i do fuel. (good thermostat, checked off)

02 senors needs a working heater, and yours is not monitored by the ecu.
(a blind spot)
to attain close loop?
motor hot (it is) the 02 heater must be at 600F , who knows.?
The 02 starts swinging as it nears 600F.
if the 02 dont swing at idle or at a steady fast RPM (2500 is good RPM to use) ?
then we work the too rich or too lean angles? based on real 02 readings.
stuck at .5v
stuck at .8v?
that is the path , find what its doing wrong. then work the angle.

i own a clamp on current probe that allows me to check the heater currnent.
its right there on the fire wall that connector.
i break it out and measure it. 0 amps,02 heater is burned open.
this btw, is the top o2 failure,above 80k. (about)

in a 1996 car, the scan would show, OL , full time all the time (openloop)
that is the nice thing about scan tools , it shows you the live data.
not a box of meters and tools. and long labor finding bad inputs.

[Swansen]

well, been awhile, but, i haven't been driving the vehicle and after a summer on the road i have my life a little more settled back in(income and all that).

So, decided to start up the tracker and drive a little bit, and yes, now i'm getting large power loss and misfire before it warms up. Got a DMM and looked at the O2 and its fine at idle, swings nicely at idle. However, under high rpm it sticks around .8v, so, considering the symptoms, it seems like O2 as a whole is bad. O2 heater definitely isn't working and probably the O2 as a whole has failed.

Once the car warms up it runs fine, but, still getting really poor mileage. I'll have enough money in a week or two to get a scan tool, but, my hunch is that the O2 as failed.

[Bex]

The o2 sticking at .8v, etc., is not a definitive test of the o2 'failing' as it may very well be working correctly and actually seeing a rich condition that it is reporting. Normally, when the o2 is failing, it fails lean, meaning it would fail with readings close to 0v, which would force the ECU to add fuel to create a rich condition, in order to protect the engine. Your o2 is working correctly at idle, and then reporting a rich condition (.8v) when you are giving it high rpm. By reporting a rich condition, your ECU is actually trying to take fuel away to compensate for this. I would actually think that your o2 is working as it should, and reporting a rich condition that you actually have.

[xxx]

under high rpm it sticks around .8v

driving or in neutral, , what rpm , under 75%throttle, state condtions (and hot or cold)

what DMM, does it show min, max and center screen average.
a real meter, shows, the 3 readings.
ill assume it o2 is stuck hard over to .8v./
if true, stuck.
why is the only question
Great testing, and a top #1 symptom in EFI testing. 02 stuck. a beginning....

the 02 on that 95 , will stick high for many reasons. not only a bad 02
some 02 can fail when hotter. just because one seems top work s at idle don't mean squat.
it is a 100k service part. try a new one, for $20
but if
ECU dumping to limhome off idle. (closed loop ends) scan tool show that... but...no have that....
ECU dumping excess fuel for any reasons what so ever, presume 02 is good)
btw: if you read the full bosch docs, the sensor is designed to fail lean (forcing rich)
(but not always)
no scan tool means we cant see LTFT going way lean, like -42% see fsm for max.
eg: reasons.
fuel pressure excessive (FPreg bad)
injectors leaking. ( 6 tests in my injector page)
there are lots of ways.

if the 02 stops swinging as you said at light cruise, that means you have a failure.
the 02 must swing in closed loop. at a steady RPM less than wot.
if you had the scan tool , you'd see LTFT at huge minus numbers, subtracting fuel
but failing to hit closed loop.
injector leaks or excessive fuel pressure. (Fpreg bad)
congrats on finding the 02 dropping out , FAST rpm (UNKNOW CONDITIONS)

your power loss is not lean bog misfire,
your power loss is gross rich misfire. power loss. apples and oranges difffernet
ID BET THE SPARK TIPS GO BLACK. or chocolate , at fast rpm fail point.

there is no full 02 tests on or off car.!! sorry !
that is a fact. sure you an find dead ones, but more than half bad o2s are NOT DEAD
they are biased or intermittent or have bad heaters./

one way to see if that stuck 02 at 0.8v can be woke up (ASE text book example)
is to , (ADD air ,or cut fuel)
you can cause a vacuum leak that ADDS air, does the 02 wake up, at the failed (im guessing 3000 RPM netural hot test)>?
does it, that means the 02 is fully awake at that exhaust temp.
dont prove its good, but is better.
you can reduce fuel flow by applying more vacuum to the FPREG nipple.
but that assumes the FPReg even works, for all I know its stuck at 50 psi.

If you can not gain control over the 02 , with ASE tricks
we do the injector balance test, and leak down rates. 1 by 1..
if you have a bad injector the 02 will slam rich. ( 2 ways)


lets back up to the Macro view.
1: good motor, is compression good. WOT.
2: is spark timing at spec and wires not crossed over, 1,3,4,2 is correct no others.
3: is fuel pressure at spec. at fail.

we always start the EFI tests with fuel pressure, all other tests are a wasted effort
if fuel pressure is out of spec.
totally.

happy hunting...