i do feel your pain, and wish to help @@
sorry , but engine problemes that are intermittant are the most difficult of all. even preventing a safe drive to a mechanic and worse, you get there and all symptoms vanish.
any time a good engine (you know it is, ) fails.
we first check spark at all 4 cylinders and on this car the coil top. 5 places.
if spark is good, check for flooding, if flooded, cranking WOT, (wide open throttle , will cure the flood)
that code thing turned off is totally wrong . forget he said that. i think it was misunderstood but? how can i know that , i didnt hear it.
first off YOUR ECU does NOT make spark, 89/90 run a stand alone, Distributor a DIZZy.
so you must check for spark when i dies. or spend a fortune guessing.
This ecu loves to fail too., they have bad caps disease.
I see your drift, your wishing the ECU can magically tell you why it wont run. (it might)
I want you to know, id love to fix your car, for free, if you were my neighbor id be there by your side with 6 major tools in a bag. and 1hr. later it would run. im in Texas.
The car has only 1 magic,
at the failure, not AFTER it runs.
insert diagnostic jumper.
key on,
what is the flash code, 12 good, no flashing at all is a BRICKED bad ECU, ECU's all have backup mode, Bricked, the main ECU is bad and this brick stupid ECU(sic) takes over.
so lets say, code 12s. engine wont start.
you crank for 5 seconds, (this magic time, allows the ECU to see spark fail)
you release the key.
do not turn off the key.
watch the CEL, see 41's if it flashes 41 NOW, that means the DIZZY is bad. (dizzy guts or main ignition coil,) (note i never assume parts that are new are good, )
key off, (41s are now forgotten)
that is it for ECU brains 1990, it is a dumb system.
i can see you have not read my pages on CEL, DTCs, nor that dizzy. but i do know it is confusing, and the evolution in 1991 to full ECU spark generation, timing , advance ,etc.....
so i will help you
Do I need to need to pull the the dome light fuse to stop this?
first off , for get the notion.
the DTC (error) memory , never stops cars from running, its just tests that fail and the DTC codes are stored there, (think of them as HINTS)
your engine will not start for the below reasons. i will list them all. (its only 3 in macro forum (engine,spark,fuel good) but ill expand on that)
1: lost 12vdc to the COIL or ECU. (lost to coil, no spark, lost to ECU fuel stops dead)
2: lost engine compression, yes, these engines have solid lifters and need service, so if lash is at .001" (gross error) then hot the compression falls like a brick and engine dies.
2b: CAT melted renders the engine totally useless, it blocks the exhaust 100% and there is no more air pumping action, nor vacuum to suck in fuel.
3: lost spark, you grab your test spark plug, from pocket , insert it in the coil output heavy wire end , ground the spark shell, and crank, OMG, no spark, the dizzy is hosed.
3b:ok you have spark at coil, and at all 4 spark wire ends, this is a test. not guessing, all steps are tests. no tests. no evidence and no solutions, ask for help testing.
4: bad fueling, you remove the spark plugs. (cheap tool) and behold, they are bone dry, (more tests) ask.
5: same as 4 but they are dripping wet in fuel, over fueling or flooding. is cause. (after all spark is good so ,, it must be overfueling)
the above tests will take you to the exact problem every time.
my wild guess, you took a running car to a mech and asked him to fix it? ( he can't because,its not broke, he will then gue$$ at your expense, he will, i promise)
the dome fuse , erases non code 12s from memory, it does nothing else , to the ECU, period.
lets start with a dead engine. and we can find why it fails.
a spark plug wrench and new spare spark plug , gapped to 0.028" note the leading zero there.
I need to know which Diagnostic port you have first.
have you lost your cab fuse box cover yet,
Geo Crackers, (wifes name) had 2 types of DIAG ports, (Suz, style 89, then 90 Geo style, then back to Suzuki style) all in 2 years, a royal pain that is. but we deal with it.
so do you have a diagnostic fuse port. seen here. first photo, we can start here.
http://www.fixkick.com/CEL/DLC/DiagJump.html
if you dont have that fuse box, then go to the next photo of the white connector, see in 2nd photo above.
put the jumper there. the fuse if present or the B>C jump (paper clip bent, not plastic only metal clips work)
no code, key on, means the ECU is dead,
stuck glowing means the NAG feature is SET, defeat that (ask)
flashes 12, is good.
flashing 41, means bad spark (it really means bad Tachometer signals)
some other codes, running, or just cranking.
you can drive all week long with the jumper insert, why not do that. and then when the engine stalls what did the CEL do.
1: go dead and out.
2: stuck on, but no longer flashes.
3: flashes codes, (write them down)
here is my flash code list, this is ALL it can do, they are only ECU hints, the ECU sees an error and logs it, in this business we say it THREW DTCs.
http://www.fixkick.com/ECU/DTC-errors/DTC-jtgh.html
btw2: the cat melted because the EFI system allowed gross rich misfire.
this older system loves to do that, the ECU goes to limphome and the driver ignores the CEL lamp on, and the CAT melts.
on new cars the CEL flashes, (means cat is melting)
forget all that, drive with the Diagnostic jumper inserted, until such time as the car runs perfectly, then take it out.
this will tell you LIVE failures.
the dizzy on this car , has many failure mode, (unlike a 91-95 that never ever fails) when i say that it means 60k mile tuneups are done..... service is done.
one think about this car, is the easy to do spark tests. the spark plugs are not burried , like on new cars, nor covered by COPS, they right there , and can be tested easy.
off my old dizzy page,
see this photo this is the VR gap. in the FSM.
i grab the top shaft, and YANK (im a bloody indian not yank, lol) and if the gap varies, that mean the DIZZY main bearing are bad, get a new dizzy now.
set the gap or the VR will fail. it must be per the page, hell, it sill love to fail hot, or odd times, (the VR + ignitor are pair)
then i uses my strobe light (automotive std, timing light, xenon) and check for full advance (remember the 60s) and if its not advancing (vacuum line unplugged) that means the DIZZy
internal fly weights are rusted and seized.
then i do a Vacuum advance leak down test with my hand held vacuum tool. if fail i buy a new one, if pass , i make sure vacuum applied does in fact move advance inside. all very easy to do.
http://www.fixkick.com/specs/89-VR-calib.jpg
that tool above , both are $20 at harbor fright. dirt cheap.
the dizzy on this car , has many failure mode, (unlike a 91-95 that never ever fails) when i say that it means 60k mile tuneups are done..... service is done.
one think about this car, is the easy to do spark tests. the spark plugs are not burried , like on new cars, nor covered by COPS, they right there , and can be tested easy.
off my old dizzy page,
see this photo this is the VR gap. in the FSM.
i grab the top shaft, and YANK (im a bloody indian not yank, lol) and if the gap varies, that mean the DIZZY main bearing are bad, get a new dizzy now.
set the gap or the VR will fail. it must be per the page, hell, it sill love to fail hot, or odd times, (the VR + ignitor are pair)
then i uses my strobe light (automotive std, timing light, xenon) and check for full advance (remember the 60s) and if its not advancing (vacuum line unplugged) that means the DIZZy
internal fly weights are rusted and seized.
then i do a Vacuum advance leak down test with my hand held vacuum tool. if fail i buy a new one, if pass , i make sure vacuum applied does in fact move advance inside. all very easy to do.
http://www.fixkick.com/specs/89-VR-calib.jpg
that tool above , both are $20 at harbor fright. dirt cheap.
if not flooding, (is it) and not dry for fuel ( the injector can be watched, with naked eyes, horn off))
but spark is bad, then. read this.
see my page in this dizzy here, hit control + F5 after load of page.
seen here
http://www.fixkick.com/IGN_timing/no-spark.html#89