Truck randomly doesn't want to start, will later.

[fixkick]

forget 1995 to 2019 toyota, or Nissans.
this is a suzuki 89
and is there first try at EFI (weak)
first try EFI TBI
first try with a NO SPARK ECU, it's a Fueling only ECU, so is very unique, (read like no other cars on the the road)
a shop will get real confused, until you tell them the above, and most go wtf is this car, ALIEN? answer YES>
Odd as odd can be it is.

flooding it is,
by your words

[fixkick]

the wet soaking spark plugs is your 1st and best clue.
it is flooding,!
caused by, many things. but ... we test on.
the super secret magic unflood mode fails (cranking WOT cause all ECU to cut fuel 100%) and can be seen to do so with EYEBALLS on injector)
if the injector cuts fuel as it must WOT cranked then the spark plugs are crap (carbon fouled) or the compression is BAD.
if the inject do not cut fuel then the injector 0rings are cracked, or the ECU bad or the ECU injector wire pairs have damage or hacked as seen many times on this old car, and sad to see.)
some hacker love to fix dead injector by hot wiring the injector, that causes the ECU no not really control fueling as it must. and floods forever.
I have no history on this car , years owned or service done.
nor can i see it and see obvious damage or hacking to it.

[fixkick]

It isn't flooding, tried cranking with the throttle wide open.

this makes no sense at all in first post (sorry not picking only you,just clarifying)

has fueling
has spark
but spark tips are dry.(no way)
this is a gross contradiction or you only cranked normally for say 1 t 5 seconds,
crank 3 times, for 5 seconds long, rest 1min between cranking sessions ( delay, 1min, saves damage to battery and starter motor )
see now the sparks plugs are soaking with fuel? sure they are, they MUST.
are the tips white, tan or black ? you never said color an that matters as does dripping in fuel, or oil or antifreeze. all evidence matter, even lack of.


Id say it is flooding, but if spark is good, the compression must be dead.

there are other rare failures, sure.
endless, even melted cat or ECU in limphome mode or far worse, HORROR MODE CALLED BACKUP mode.

key on, CEL lamp in cluster glows. (aka MIL aka SES)
if not ECU is sick or lacks POWER 12vdc .
I then insert the diagnostic jumper clip (or fuse as seen on some 89)s and make sure code 12 flashes out on the CEL lamp, if not tell what it does,.?

in backup mode the CEL lamps is DEAD and will flood and flood.
in limphome it will flood randomly, based on many facts. (air temps etc)

The diag fuse cars is left knee fuse box fuse.
if not there, its on the DLC 4 pin connector just in front of the battery. called DLC, diagnosic link connector.
a paper clip is used, type DLC or CEL in my search box in my signature below.

[fixkick]

keep in mind it is just a simple engine and car.
know that if that VR acts up the engine may flood, (if the ECU sees VR dead,, it does cut fuel) but if VR makes weak spark so weak can't run engine the ECU may think it is ok)
The ecu only sees the coil primary signal not true live spark real, just the primary side, so can be fooled easy. ok? ECU fooled.
so then the engine floods.
and say spark returns with the engine shacking hard, cranked, the bad VR might wake up or the bad ground to the distributor makes a better connection
but now with flooded engine, the engine may not start, until the spark plugs are dried out.
see>?
then engine never dies running or fully hot, 180f if fully hot, if not the engine will flood.
It only fails , from engine of point.
are hot restarts more easy or less easy than cold.

all testing takes 2 persons to find intermittent starts.
or buy a remote start hotwire stater button as sold in all autostores, forever. for one person testing. (2 wires, 1 to battery + one to small Faston™ terminal on the starter solenoid,
chock front wheels, and be in neutral and had brake set hard, even 4wd neutral for more safety first.

one more issue on flooding, (its and old car, most flood this old, lots of ways)
1: the IAC in the base of the TBI throttle body goes dead.
2: engine will want to not start.
3: so not using WOT< only add 5% throttle (mean tiny bit) and crank this fools the ECU into thinking (ouch) that the IAC is not dead. and now fuel and air are not near perfect and it start.

cold starting
IAC is just a thermal air ADDING device, if dead?,IAC, the air goes to 0. and you can not start any engine lacking AIR. (on a hot start the ISC is the air supply (and tiny bit from TV)

[toolman21]

Normal service. Head was rebuilt 8k miles ago or so. New timing belt, plugs, wires, coil, distributor cap, rotor, etc during that time.

Plugs look exactly as they should. Not black or brown.

At this point I think it is the ignition switch or the distributor.

Is the distributor serviceable inside or do you just have to replace it as a whole unit?

[fixkick]

if the car does not stall from spark lost driving why would the igntion switch be bad and if it did die on the fly stay in gear, foot off clutch and wiggle the ignition key if engine goes live again, the switch is bad.
the inside parts for dizzy cost more that the whole thing.

https://www.rockauto.com/en/catalog/suzu...butor,7108

suzuki wants over 6 times that 180 cost.
suzuki shows not parts sold inside, only full dissy and coil.
(sure cap /rotor )

what you can find world wide after market parts on a car this old, i could never guess.... (take endless googling to find that)

the guts are here
https://www.rockauto.com/en/catalog/suzu...(icm),7172

[fixkick]

one can replace 20 parts only to find 1 ground bad, and now $ broke.
the old parts book, from suz.
1989 shows,
p/n for whole ignitor assemby as

33370-60a10 $510 seen at calif suzuki (garden grove Ca.)
cherryhill NJ, $440 suzuki parts sales.

SMP is top Aftermarket maker, famous.

https://www.partsgeek.com/catalog/1990/s..._unit.html


https://www.ebay.com/itm/Ignition-Contro...ctupt=true


https://www.carjunky.com/ignition_contro...parts.html

[toolman21]

Thanks you for your help.

[fixkick]

good luck and I hope the 1 part is bad.