'94 Tracker hesitation/stuttering at low RPM smooth idle

[fixkick]

it is a
franken-kick
or franken-sammi

EFI issues can get dicey fast like that. (gee I look and see a little of this, and a little of that.. hum.........)
I call, bad grounds first.
then bad C103 2nd/
last possible Alternator gone mad. (those huge old DIODES inside) if voltage is near 14.7v running it is mostly ok.

The ECU is malfunctioning, for sure. only why remains

[fixkick]

i think the ECU also blocks EGR cold engine, until magical 150f is hit, then with foot in throttle, EGR goes active
then if you go WOT it goes inactive.

the reason is simple, NOX gases are not generated at cold engine rich or idle , nor wot. (wot goes rich too)

[fixkick]

that above plot by suzuki shows the VSV going off line in 2 places. idle and wot.
but is also off cold. (most are like this, but I cant speak for 50 markets, only usa and a bit of canada.)

[dstaheli]

Thanks for all the great info. Yes TOS was a typo for TPS. Yes I notice the chattering of the EGR VSV with engine running, hot, and opening throttle by hand. To disable the EGR I unplugged the VSV and disconnected the vacuum line from the EGR modulator and plugged the vacuum line. I did open up the ECU and did not see anything visually wrong. I also swapped the ECU with a spare and it acted exactly the same. I think the grounding issue may be a good place to look. I did have an issue with headlights not dimming a while ago due to 12vdc feeding back through the ground wire from the switch in the steering column. I will see what I can figure out with the info you gave me. From what I can tell the wiring harness is the stock harness and wire colors and plugs match up to everything I have looked at so far. Thanks again!!

[fixkick]

VSV egr ,,must not chatter,ever, if that is the ECU EGR VSV control line , bouncing from 0v to 12v then 0v, that is the ECU messing up. ( a fact for sure, only why remains !!!)
ECU messup for many reasons, bad power, bad inputs, or even so wire to it shorting to the body or frame, one such wire is the damn 02 power wire, will short and ecu goes MAD.
that is why asked to unplug it, and for sure make sure the 02 wires are not burned, and touching the body of car (ground)

you "unplugged the VSV" does that mean the electrical plug, or unplugged vacuum lines or all 3? please use all words, vacuum or electrical when you say unplug...xyz
head lamps not dimming?, i think you mean low beam failed,(high and low beams those are ) (some call it bright;dim but is not what it does,electrically, it is high .low BEAMS only)
when I say dim I mean the lamps , are dim, as in 12vdc to the lamp is now 10v or 8v. due to Alternator went dead or if the ground wire to the bulbs are rusty, loose or bad. causes invalid ..voltages (low) to the lamp, in electrics the hot side 12v or ground side can fail.


we use a volt meter to see voltage drops, , and why, easy.
Key testing methods use:
use the batteries negative lug as a reference point to prove that, ground is 0.5vdc or less, suzuki spec.(small wires)

good a stock harness in your Frankensammy, at least there will be no missing wires. only bad or missing connections or shorts.

the ECU is just small computer, and like all computers it needs
good grounds to it and all its sensors and actuators (vsv is and output actuator)
good power. 12vdc good, 8v not ever good.
VSV logic.
then the idle switch closes at idle, and opens off idle. to 5vdc on the TPS, idle switch pin , A18 on the ECU, is idle pin. seen in the schematic and below.
with the engine hot the EGR is electrically enabled. when the idle switch opens and stays active driving (5vdc) , unless you WOT the throttle, and the TP pin B7(ecu) goes to 4v about.
just like my flow diagram above, the EGR shows see that active zone is off idle?, it does not chatter, no VSV on this car chatters,
the flow profil is all done by VACUUM magic, we will not discuss that now, as this is a VSV hard nut failure, here. (why unknown now)
You changed ECU then didnt tell both ecu suffix part numbers, used, why? ECU numbers matter. always. 58Bxx (what is xx, all i need is the xx code) there. every time you talk ECU.
If i had to guess bad grounds on the wires on my list, G100 up. they all must be present, and clean and tight no rust , no loose bolts, tight only works for grounds, for sure.

if you know how to back-probe the ECU connector using meter (volts) and one back probe needle you wn watch the pins on the ECU. live,
mentioned here.
http://www.fixkick.com/sensors/tests/TPS...backprobes

but what ECU is there, you have not told me that, nor your door counts (sure 2door sammi body) nor transmission type 3sp./4sp or 5sp stick"
try to know that im clueless as to what 94 car the parts were removed from, totally, all; I know now is 94 and G16B and NOTHING ELSE. not even country told.
ECU 101:
94 16v, uses 33920 is the prefix code on all ECU the the suffix codes
MT -58B90 ecu
AT- 58B00 ecu. B30 is calif version 00 is fed. if car was sold in canada new, it has its OWN ECU, that is why I ask the suffix numbers on both your ECUs ok?

you will have one of those, AT = autotrans, MT = manual trans, that you not told me yet. (im sure sammy is 5sp, but what was the donor car, im clueless, but the ECU will tell me that.

all 1994, then 1995 they changed,
since this is a FrankenSAMMY, then anything is possible, until seen. (the label tells me what is there)
Actions to test:
so what I do is read the sticker first so I know what ECU I'm dealing then goto the below link.
to the ecu page
seen this yet? all pins documented here, 92-95 G16B 16valves. USA.
http://www.fixkick.com/ECU/16v-ecu-pins.html

and then the 2 pages linked there. fsm pin page 1 and 2? bingo for checking voltages in these ECU.
step one. (bests is to inspect the grounds in the G100 table, after all , you go ,wow looky here, the distrib ground harness is just loose, sigh.
1: connect the voltmeter neg black wire (on volts ranges) to the battery neg lug, Use a long jumper wire to do that, this lets us find bad grounds effortlessly after this step is done.
ok the meter now has a perfect ground now. (vital steps)
next?
2: back probe the ECU connector pins, using a needle or real needle probe. in the red meter lead. to the ECU pins.
3: check the key on voltages, first, see a15? that is your VSV pin, EGR.
check all power pins and ground pins first. 12vdc is power, ground is 0v, , 0.5vdc or less , 1v is BAD grounds.
Pin B6 is 5vdc if not 4.75 to 5.25volts the ECU is bad or that pin is shorted in the harness somewhear, the page 2 link shows red stars, those are all critical power pins (ground is too, B1/B2)

those tables use the B+ symbol this means battery Plus voltages, 11.5 to 12.5 keyon, running engine is alternator voltage about 14v, ok? that is why they say B+



warning do not be confused and A an B connectors
GM in there great wisdom (sarc) changed B to A. wow , but no the numbers , omg , lucky us.
in my pages B is the powerside.

as seen on my page ecu for above car here.

[fixkick]

as you can see the VSV transistor is Q111.
the ECU turns on that transistor off idle, and the output of the transistors Collector energizes the VSV coil,
The VSV is vacuum valve solenoid, it has coil bobbin inside just like a relay does.
this coil logic on most Suzuki's works backwards. (to most folks)
with the key in hand not in car, the valve is open. (oddly and makes smoke testing for leaks confusing? see?)
when you key on the valve closes, (vacuum is blocked to EGR)
then you start engine, valve is still closed. (closed means vacuum dead to mod) closed means energized, coil in VSV.
You step on gas pedal and VSV valve opens, and vacuum modulation magic happens, (we will not talk that now)
at no time does the ECU attempt to modulate the VSV ever, the MOD valve and ported vacuum in the TB does ALL THAT. not the VSV.
ever.
my point above is watch out for VSV that work backwards, they do on suzuki's (some are open , key off so just be aware of this)
once you turn the key on;the valve is 100% closed . and never chatters, Q111 does not chatter ever, (good cars well, trackers not molested etc. )
THE CAPS BLUES: (like the song always in my mind... lol)
see that C103, almost ever one I have ever seen are BAD. (of Day 1 original I MEAN, 24 years old NOW)
did you know that?
some just go dry inside, with no signs outside of that fact.. Ghost failed.
if the side is marked, Rubicon, it's doom city,, all fail, (i can say that because all other brands ive seen are good, even this old. so Rubi , was trash caps then)
failed if used for 10 to 20 years, everyday , car parked in hot sun. (180f cab temps are common)
the only one I have not seen bad that year made, is ECU new in a box on a shelf parked..
I always remove it , and put in Nichicons, per my pages. I get them from mouser.com I buy the HIGH TEMP versions, 105C and this brand I LIKE. (top brands matter) here.
If lucky one can find Low ESR cap but not always can I find them.

on any sidekick B16
we set the front crank shaft 17mm head bolt to 94ft/lbs day one. owned (no wrecked crank snout is the reward)
then replace C103, next. (the corner cap I call it)
for sure those 2 steps, allow the car to have a future;. just 2 steps. and sure the other red DOT cap there fails to, just less often.

many times is see the cap is already changed out, (different brand) and is ok. I use a ESR meter to test them , but new is always better.
after metering vast numbers of caps in a life time we learn who made bad caps and who did not.... Non of my old sound gear with NEC caps failed. ever,
that cap is 24 years old today, 4 years past design life, in my opinion, 14 years past due to bad vendor.... maker of cap.

Mouser changes cap links so here is a revised page. links check it out.
I use this cap from Mouser, dont let the price scare you, LOL

https://www.mouser.com/ProductDetail/Nic...Ss4w%3d%3d


hint1,
if the grounds are bad, many things fail even this cap above is near useless , lacking good solid grounding to all ECU ground pins. per the schematics, full.

[fixkick]

if the cap is good
the grounds are bad.
I bet.
I bet the TPS is not cracked in half inside like this one.

do NOT attempt to open your TPS.
we did this after proving the TPS is bad (we used a scope ) and found it was vibration sensative and bad.
the we did this, gently.
the point is , to use meter or a scope, to see if the TP pin or Idle Pin fails or bounces, ops, its bad, or wires to it Bad.
this is tps guts the TPS was cracked due to bad engine pulling steps, someone smacked it and it cracked, oops a daisy. it is thin Ceramic inside and fragile.

[fixkick]

if the TPS chatters so be VSV egr. or even the VSV EVAP too or both.

if the TPS good, then the ECU has bad grounds, I bet. or that silly C103, DEAD, 0uF on meter. dead as a door nail.

[dstaheli]

Again, thanks for the great info. Below are pictures of the 2 ECUs (59B30 and 58B00) I have installed and a picture of the corner cap. I am going to go through and check all the grounds, power pins, and inputs as soon as I get a chance. Thanks for the great charts should be very helpful.
           

[fixkick]

58b00 ., is for automatic transmission is this car AUTO you never told the drive line, now,. (im sure the donor car is UNKNOWN so we must learn that the hard way.
that cap is new, its been swapped or the plant that made it ,hated rubicons, bless that. idea...\
58b00 is AT ECU fed , 94
59B30 is AT ECu Calif 94

The harness must match the calif and fed. both if wrong, set up DTC 53, and the EGR will be dead. (or god knows what effect that is)
Run the FED ecu , it does not need the EGRT sensor, but if throws 53, that means the harness is Calif harness. wrong.

i say bad grounds.
#1 cause of Frankensammi issuers are,
wrong wiring, bad grounds.

those 2 ecu are not happy at all if the VSV chatters,
check the coil on the VSV 2 pins, 35 ohms resistance?
not 0 not 5, not 10.but 35. (25- 36ohms is spec in the book)
if the coil shorts that will overload the ECU, or blow it up (1 transistor Q111)

Those harness ground,
look for them in the engine bay
see all them are solid black wires
and have ring lugs, (to be bonded to and object ) via bolts.

the battery neg lugs goes to the top starter bolt only and must be tight, if you get this wrong the next bround strap burns up cranked. next line below.
it also goes the body strap,, this large wire, to body. on the original car. does yours have that body to battery ground straP, OR IS IT MISSING? or burned up or rusty or loose.

LOTS OF FUn making frankenkick run right. grounds tops my list.
after all the orig. body is missing oops, and with that all grounds (most) now missing see? ( the guy doing this guess where to put things,)
,
the list is accurate i gave you, it's out of the 95 manual same as 94 , except EGR wiring (2 wires there at EGRT sensor not on your car)
G100 etc.
Id never own this car lacking the 94 tracker FSm,
car fail all the time, why no have the book, to solve problems that no Sammi book made can do. (all wiring EFI is now alien)