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Cold Start Issues
I don't want to complicate things, but I will give the background then my symptoms, what I've tried and I'd really appreciate any direction you can send me on.

I had an 87 Samurai with a 1.6 8V swapped in. I bought another Samurai with a 1.6 16V from what I was told was a 97 Sidekick. I decided to entirely swap the motor, fuel tank, and all the wiring into my current rig back in 2012. It ran perfectly in the original rig.

All this to say I didn't create the harness, the motor is essentially run off the original sidekick computer only. I have an in tank fuel pump that was installed into a samurai tank that I swapped over. I never had any issues with the motor when it was in the first Samurai. Ever since I swapped the engine in to my current rig I've experienced varying degrees of hard starting.

97(?) 1.6 16v, Calmini SS header, Custom intake tube that replaces the stock intake to a Cone filter that sits inside a custom box that uses the stock MAF and the air temp sensor is attached to the box right next to the intake. There is no charcoal canister or the EGR pipe that runs through the block(?) which I've seen on stock rigs.

Starting issue:
Cold weather has always accentuated the problem, if the rig sits overnight or for 4 or more hours it take 3 or 4 prolonged starting periods. (40F or lower)
In the summer it may only take 1 or 2 tries (70F or above)
Often in colder temps I've had an easier time pumping the gas a little (I know its FI, but I was just trying something, I know it should have a flood protection)
When it finally does start it jumps up to about 1500 rpm (in the winter) and runs perfect, but its is definitely quite rich when it finally fires off.
When its warm it skips the high idle and generally just goes to about a 900 rpm idle.

Performance wise it runs great. Warm restarts are generally no problem.

Here's been my trouble shooting:

1. Am I losing fuel pressure and it takes time to build the pressure back up?

-Replaced injectors (suspected leak down)
-Replaced Fuel Pressure Regulator (suspected leak down)
-Added inline fuel filter with check valve near the tank early on suspecting the pump was leaking down
-Finally added an AutoMeter fuel pressure gauge inline on the intake side before the rail to keep an eye on things.
- After an hour it will have 26 psi
- 1 cycle of the key to run (pump on for 3 secs) goes to 40 PSI
- Running it sits at about 34 PSI at Idle

I feel I've ruled out fuel pressure. Noid lights appear to show the all injector harnesses are behaving correctly

2. IAC:
Pulled and cleaned orginal. It seemed to help, but problem hard starts persisted.
Swapped in another I had laying around from a used intake from another rig. No change. It was used, but not bad looking. Still not confident so..
Swapped in a clean one from my brothers 1996 Tracker that runs perfect.
No change.

3. Checked and proceed to replace:
Coolant temp sensor - has 4.7V with key on
Air Temp sensor- has 4.7-8V with key on
IAC has 4.8V with key on
Rotor and cap
Checked timing (I can't remember its been a few months, but it was in spec, but I can check again)

What do you think? I'm usually the one helping other people on every other part of Samurais and kicks, but this motor is beating me.

Please ask me anything that might help you understand the situation better, I can post pics of the engine bay and the set up if that helps.

Thanks so much for taking a shot at it.

welcome , Malcolm.!!!!
a custom car, and that is always a complex topic, what parts, what years, fitted where, and missing parts, omg.etc.
a 1997 SAM-KICK i think it really is. tells it all if im right.

im totally confused
87 sammy, ok , that dont matter
what matters is the
what is connected to the 97 MPI engine, its got 4 injectors, how can that run on a TBI system? even the manifolds not mix....!
my guess? is this is a full 97 MPI setup , right, all parts.... (most ) harness for 97, engine, manifolds, sensors , injectors x4 , etc.
to diagnose any problem we need to know what engine, and what EFI you run, even the ECU part numbers.
after all the ECU runs everthing, there. spark fuel, idle , all.
even bad idle air supply cause the engine to flood.
that is 100% legit, the new cars all have the 2 lines now. opr guide.
1: if engine flooded, crank 100% throttle (WOT) this cuts fuel 100% and clears the flood with vast fresh air. (TV air)
2: if engine is hard to start, not flooded, at 5% throttle to help.. they added this line because some times the (gee common) the ISC sticks closed.
the PCV+EGR gas cloud of death gunks this up.. and more...

900 idle is wrong hot 850 i s max (if you have a real tacho, or scan tool, if dash meter, well 900 must be really 800 as this gauge lies easy)
1500 is normal that is IAC doing that. until 150F is crossed (water temp)

fuel pressure is good. all that. and you skipped nothing , but balance testing. of injectors using same tool.

By IAC you mean the ISC. (back in the old days suzuki called them both IAC, kinda silly that, so now uses the correct ASE names)
no need to argue names
or use IAC-E (electric or IAC-T (thermal)

the hards starts, im my opinion (ECU scanned yet, that is first) all 97 scan with $10 tool. used one yet?
iSC not opening fully , with warm start or the IAC is not opening;
the IAC must be open full cold. (mounted below the TB it is) wish you had said where your IAC was located.
the ISC is electric, and is mounted on the left side of the plenum. its easy to test. ask. both are.

the coolant sensor has 2 pins gray-yell is ground 0vdc.
the other pin is pulled up to the ECU internal 4.7v supply
my guess s the Red-yell wire is at 4.7 (4.75 to 5.25v is spec on your good supply but how ever
the ground is open on the ECT and IAT.

That ground is called ECU super quite ground. and is just a buss bar in the ecu to real ground/
so if i knew what color wire that was.
and the ECU partnumber, well, this gets more easy.

must be 5speed manual transmission
with matching ECU.
the 97 that ground wire can be brown on some markets.
[Image: 3_03_12_15_3_21_24.jpeg]

the scan tool will barfing DTCs for that. for sure.
but most sammy owner like this , connect up every thing but the 2 DLCs
DLC1 OBD2 scan port
DLC2, the very much needed timing freeze jumper to get timing right. did you>?

a dead ECT causes flooding
because of 2 reasons, 1 it can thank its in alaska, and that be -40F max cold and floods
but worst happens this failure causes FAIL SAFE and that cuts idle controls , goes rich as a pig, retarded timing, and weak starting air (ISC limited)

why not get $10 tool and see what else fails , i bet lots.

the ECT reads 300 ohms hot.
the ECT ground is 0v
the ECT hot wire is .65v hot.
per my ect page

set that table, i calculated all ECT voltages, Its not in any books,, just here.

boy will you be amazed when all this ends, like 2 times more power....... amazed....
failsafe is no place to be

is this 97 , even missing the CEL lamp , yelling SCAN ME?

easy peasy japaneezy

good luck and glad to help. i love, samokicks.
Wow. First thanks! This is like drinking from a fire hose.. I'm going to attach some pictures I just took at work of the engine and tonight I'll pull my ECU out from under the dash and provide you with some pics/numbers so we can better understand what I have. One thing that has always confounded me is that I have no standard OBD2 which I thought was standard above 96 (other wise I could use my code reader). All I have is (what I've researched on your site to be) a DLC. Which makes me think the engine is not a 97 it must be a 92-95. Now I don't believe I've hooked that up to signal the light on the cluster, but I understand I can use analog multi meter and count wags. I'm going to spend time reading your "http://www.fixkick.com/CEL/DLC/DiagJump.html" today and apply it to retrieve some codes this evening, but in the meantime here are some pictures to help you get a general feel.

Thank you again. I've been entirely in the dark until now, and I'm excited to see the outcome working through this..


A few more pictures of DLC and what I could see of the ECU..


Attached Files Thumbnail(s)
nice rig! seems you have a real 1997 harness. good....
it's mostly all there
but the 16pin under dash, DLC connector , OBD2 missing?

you found the under hood DLC, was originally behind the right front head light shell.
seen here.
6 pins, jump 4 to 5 to freeze timing, to set it to spec. with a timing light.

let me look carefully

here is what your 6 pin does.
i horsed it up.

off the 97 schematic page

[Image: 3_03_12_15_6_39_34.jpeg]

the DLC1 (OBD2) is above right knee in all USA 97 sidekicks and trackers.
if you scanned it with any scan tool made it be barfing errors like made. DTC errors diagnostic trouble codes.
it would, because your sensor grounds are open

most cars with this error food and die. fast.

thanks for sharing photos ,nice to see a SAMMI locking real sharp.....

here is the 97 DLC1, OBD2 16pins, D-shell shape connector

the DLC1 connector underhood, has a rubber cap. unlike any other on car.
very unique that and yells, DLC here.

got a friend with a OBD2 scan tool., scan it.
all sidekicks 96 and newer scan, with any obd2 tool made.
even the dirt cheap tools/

in my first post pin 11 ECU wire is cut, for sure. at either end or the harness.

that ecu pin 11 gray yellow runs a huge long daisy chain, and as such can be cut, in every place it stops
Fuel tank pressure sensor (EVAP diag)
EGR map sensor
both 02 heaters
all or some can be dead, depends on where the wire is cut, and is.

really one of the most important wires on the car (EFI)
More reading has yielded these results...

I was confused on the what/where the IAC was. I've always called the ISC the IAC. This was because parts stores (rockauto) called them this.

So I have never actually pulled or cleaned the IAC which located under my throttle body! In reality I've only ever cleaned/changed out/swapped in my brothers ISC.

1. Can the IAC be cleaned? How? Just carb cleaner? (I see how to test them now, thanks!)

Thanks. I'll work on things tonight and post up what I find

*EDIT Just read your last response after I posted
Correct, I have no OBD2 style port. Only the little 6 pin DLC. Can I obtain the same Diagnostic info from this as I could from an OBD2 port using your write up for 92-95 DLC?
Here's what I found:

1. Made the LED DLC tester. Gave me two errors. CODE 23 and 24. IAT Sensor Circuit and VSS circuit.

I know that I don't have the VSS mod in my instrument cluster. That shouldn't affect the hard starting should it?

IAT is the air temp sensor correct?, I've replaced it, but I have still have the old one so I tested both.
The old sensor I have read 4125 Ohm @ 49.1F
The new sensor that has been installed for a while reads 4390 Ohm @ 50.1F
Both seem to fluctuate resistance with temperature changes about the same.

If I have 4.7 V at the wires that feed it, I shouldn't have a short right?

2. I pulled and cleaned and tested in hot water my IAC valve.When its about 40F its open, when you heat it up in hot water it slowly shuts tight.
I also cleaned the throttle body out. Neither were very dirty.

I also pulled and cleaned my EGR valve at the same time.
I also used the jumper wire and set my timing to 5 DEG per my book, (some models say 8)

I'm letting the rig sit overnight now to see if the cleanings help at all, but I still have the CODE 23 and CODE 24, so I know the computer still thinks something is a foul with the IAT Sensor circuit, so I'm doubtful.

What or where would you direct me next?

Thanks so much, I'm already miles ahead thanks to you...
yes, both SAE and Suzuki changed the names 3 times in 20 years.... but it is an electro magnetic solenoid air valve, for sure, the other is cold start thermal air valve.
i guess the car has and pre 96 ECU, you never said which ECU, and we all,in the end make it happy..... EFI runs the engine , the ECU does.
who's harness the 97?
what country is car,or what country ECU? (we can discover all that.... and is really first besides the bad ground you have)

The USA ECU 96+ has no flash codes!,(those are gone in the USA (cept 96 4speed transmission flash codes for the automatic) the USA car by law is OBD2, so its not a 97 ECU.
"I was told was a 97 Sidekick" seems not. seem like 92-95 MPI engine.

all 97 have a crank sensor. front bottom of oil pump, on engine, got CKP a.k.a. the crank sensor. seen here.
http://www.fixkick.com/my96-16v/ckp-sensor.jpg (96 to 98)USA only.... and canada in 1998.

the engine serial number shows the year, (USA laws), the letter in the center of the engine serial is the YEAR code, easy decode. on my vin page.
http://www.fixkick.com/my96-16v/my-motor-serial1w.jpg (T= 96) V= 97, what is yours?

The ECU code tops my list. what is it.? the USA US will have below the PN , MT-US, (means manual trans, USA)
the list EPC list
(guessing below, tell me and we can really (fire hose accuracy)
dash 72E01 (is usa mt0, e3 = USA federal spec)
dash 71EL1 same for Canada. but made in JAPAN
dash 72E41 same for canada but made in CAMI
with ECU in hand we have this TAG. off my tag slide show.
[Image: TAG-ecu-real-w1.jpg]
the numbers to the right of the DASH are KEY.

like that, is the way.
since yours flashes codes, must be 92-95...ECU. (96 and up dont flash at all (by law)

IAT never fails, and you measured its grown wire at 5v volt, ITS NOT CONNECTED. that is what
lower left, bell base flange. (drivers perspective = left)
G16L (L = 7 for 1997)
Ill run with (fire hose) 1995 (lacking tag data and VIN, and engine code data)

code 23 means the IAT is unplugged.. it is , the ground wire IS CUT.
code 24, means VSS dead. the builder built the car and left out the speedo cluster. and cable. this causes VSS to go dead and some ECU go to limphome mode with a dead VSS. (it limits power for sure, lacking the critical ROAD SPEED INPUTS)
if you drive it with the DLC jumper connected to DLC2(RF headlight )or next to batter pre 96, the CEL will flash even more codes.

the best cleaner is CRC MAF or manifold clear, SAFE for plastics. l


there are delicate parts in side all sensors, and actuators. just the maf cleaner is all you need...

the spark timing, is based on country, and year, and if in PR> of California (calif is a country by law EPA laws)
since i dont know either country of ECU there..??? I cant guess timing.

now that bad wire, this is very very important to running any ECU 92-98 ( or newer)
The ECU is the power source, the ECU has this Device inside called a 5v regulator, just for sensors, (the processor inside has its own 5v reg too)
Imagine a magic 5vdc battery is there, (IT IS)
the sensors i listed, above, a chain of them , (fire hose) are running off GROUND. all of them are., and is (physically odd form)
ill make a drawing for you and then apply OHMS laws. (I = E/R) I= current, E= voltage , R = resistance.)

ill do the IAT (the other sensors are dead too, you just dont know it yet , some are)

im guess'g now the Samkick is 87 sam, 97engine and 95 harness and 95 ECU, (the engine serial and ecu p/n will not lie, and is key diagnosing what you have)

here is a drawing i just made.
You measured node B and failed. that wire is CUT.

[Image: fail1.jpg]

Node B is ground. and is
lets pretend the car is 1995 ECU, (we need the ECU part number bad.)
so ill answer in short,(no fire hose)
see this, see pin B15 on the ECU , this line on your sensors IS CUT. (any where on the that line, it can be)
the wire is colored. the same. THE GRAY -YELLOW wire iS CUT. (broken)
causing up to 6 sensors to go dead, if cut mid way, then 1/2 that. i cant guess. only my voltmeter tells me exactly where its CUT. 0v good, 5v bad.


since i already found the big error here, why not find the cause.
using a ohm meter, measure
key off, sensors unplugged (they have locks do not force them)

B15 ECU pin (92-95)
to each sensor, (in list) gray yellow wire
0 ohms, say less that 3ohms, as most cheap meters read high by that.
the sensors with infinity or high ohms are bad.

lets say you read.
infinity (1million ohms or so)means OPEN CIRCUIT.

the wire is cut between the last 0 and the first infinity reading.

this works on all 92-95 harnesses in N.America., G16B MPI engines.

we can also use a test light (with internal battery) to check continuity, (this class failure is easy, the ECU even told you what is wrong)
or a buzz box. (battery )
or as bell (called in the old days "ringing it out")
to check continuity...

or just examine all those sensors , the gry-yell wire for damage,
but can be in the harness, i can not predict where. damage pulling engines is random, unless the harnesses are safed off.

what is yours ?

the heart and soul of EFI the "ECU" spark , injection and lots more.

id have had this out day 1.
then check the ECU caps.(inside) for leaking green snot
then set the crank pulley 17mm bolt to 94ft/lbs.. (A TSB DIRECTIVE FROM SUZUKI)
all day 1.

[Image: TAG-ecu-real-w1.jpg]

that one sticker
tells me volumes
what engine?
what harness?
what year,?
what country.?
what smog levels.?
and more. it also gets me on the correct schematic drawings.
just one itty bitty look..

the above example is the 8v... but yours has this sticker. (on top)
Found the broken wire!

I'll try and answer each one of your points..

1. Cleaned MAF with the CRC MAF cleaner
2. I have no Crank Position Sensor
3. With my header its not easy to see, but here's what I have for an engine code. 16 W 816451 The W is slightly marred (see pic) but I'm 95% sure that what it is

4. Checked all 5 gray/yellow wire grounds with my Fluke MM (I think its pretty accurate)
- Water Temp = .9 Ohms, Red wire has 4.14 Volts
- EGR = 1.2 Ohms, power is 4.45V
- TPS = 1.4 Ohms,
- Air Temp Sensor = 1.2 Ohms, power is 4.7V
During the initial tests my resistance test kept going all over when I wiggled the wire. I found it had completely broke inside right at the connector. I stripped it back and reconnected it with little clips for continued testing. It now reads 1.2 Ohms consistently. This might explain the error codes last night
- O2 = 1.3 Ohms
Was there a 6th?

5. Pulled my ECU out, (grounding myself) opened it. It looks clean on both sides of the board, no leaking Caps.

6. Reinstalled everything and reran the DLC test and now I only get CODE 12. I warmed up the rig for 10 min and that is still the only code. I will let it cool down and see if I still have cold start issues.

Thoughts on the ECU?
What is it?
What do you think of the engine code? Isn't that a 98? which doesn't make sense based on electronics

Also what is this? And does it need to be grounded?
wow what great work !!!!!
wow a double stamped engine, like on COINS ,its now worth $10,000? LOL !! never seen that , nice... w=98. but that w , looks like 2 V's lol, funny that.
and is a 97 block. or 98 (both are same)
means it had a Crank sensor oil pump and pan then,. see that sensor hole on pan front. (unless pan swapped from 94)
yes the 6th is o2 sensor rear, im sure missing now. on new car behind cat in a cat 02 bung and wired under drivers seat.
58B90 bingo.
usa m/t version
1994 ECU, has no crank sensor , and my guess is harness on car is 1994 !
and is California harness and ECU,
and the Calif runs the EGR thermo 2 wire sensor. if missing pukes 51 codes.
and is OBD1 ECU, no scan tools sold over the counter only flash codes work. see my OBD1 page for exceptions.
so it's a 87 SAMKICK 97/95 EFI engine. wild and fun....!! no problem making one run

ecu looks really nice, is that corner cap. top left corner, marked Rubicon? if not it's a runner.
this car is 1994, and i bet is 1994 harness and all the trimmings... end to end, but has 97 block that has no factor in diagnosis.....

all the 92-98 blocks are same, only in 1996 added CKP sensor to pump and matching pan,. which the PO removed

that red conn, twinky on the fire walls is your coil ignitor ( just a large transistor that charges up the the spark

the 96+ or 97 has no such part.
the coil in 1996 was moved to inside the distributor then with Ignitor too.

code 12, you fixed the bad ground; way to go....!!!

when driving other codes can pop
the VSS is dead, takes driving for the ECU to see that happen
and EGR code 51s, im sure, if CAT is missing.
or on the 94, the egr main has a calif . egr thermo probe, that is easy to fool.. ask.
if its bad. most never fail only get carbon blocked.

im sure idle works good now.
and front 02 swings now
and mileage goes way better.
sounds better, no misfiring
starts better.
but only driving it can test all the other OBD1 codes.... hard driving.
the ECU will go to closed loop now, and run like a new car....

this calif ecu can dump code 53s
if this is missing, (no panic)

seen here

its just the screw in sensor on the side of the EGR main, first used on Calif cars. the moved to FED later (both)
Day 2 of hard driving and the only code I'm getting is the code 24 VSS.

First off thank you so much for all the help and guidance. This was looking to be very daunting and you made it a success. I love to learn these things and pass on information when I can, so thank you.

One thing else I changed if this can help others is: I had my starter wired to a push button. If I started my car I would turn on the ignition then reach over and hit the starter. Even after fixing my IAT broken ground I was still having some problem with a hard rich start. If I cranked my starter then turned on my ignition I never had an issue. I've since rewired my starter to my key so there is virtually no delay allowing the motor to flood?? And I've had no issue. Thoughts on this discovery?

Lastly: Question is, what do I gain by installing the VSS in my cluster? My engine seems to be performing as it always has.



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