jerking

[stickerbuoy]

Yup, and in fact I had the TPS problem on this car as well (http://www.fixkick.com/bbs2/Suzuki-bbs/s...hp?tid=337). I replaced the TPS (which didn't help), and then replaced the top section of the wiring harness. After that it didn't do it any more. I suspect one of the wires into the TPS plug had an intermittent open.

It's hard to describe the difference, but when it happens it's definitely a different sensation. The TPS causes jerks that are not as sudden, and and more of the "losing power" variety as it kicks into idle.
This latest problem is a very sudden drop (and regaining) of power. It's also reflected on the Tach with a sudden dip in 100-200 rpm.

I purchased a new set of spark plugs, and placed them on the passenger seat, and now it's fine, it's amazing!

[stickerbuoy]

I think I just scared it, but I suspect the problem will come back, at which time I start swapping stuff out...

[fixkick]

very hard to find on obd1 cars, no scan tool.
0n the newer cars , you can plot sensor data, all day , with no effort.
intermittent are the worst to find. very very hard. work.
I hope your's is cured.
happy trails to you !

[stickerbuoy]

problem is back, and seems to be getting worse with time.

New spark plugs installed, new wires. Problem seems somewhat temperature dependent. Driving into town doesn't produce much in the way of problems usually (~20km), but on the way back (less than an hour later, engine still warm) it seems most likely to lose power in short spurts. Also have noticed it more when going uphill. Problem is intermittent, and may happen once every 15 minutes, or as many as 20 times in a couple of minutes.

Wondering if it could be:
-a bad valve?
-a blown head gasket?

As I mentioned before, error code 12 has been faithfully flashing at all times, even during the power fluctuations, and this has a very different feel from my earlier TPS idle circuit problems...

[fixkick]

The RED CAR?
It's not lost 12vdc, power., to EFI,
rotor ,cap, ok? plugs gapped at 0.028" never at .045 as they come from maker? never surface fire plugs, never 2J or 3J or 4J plugs ,ever.?
if the engine is healthy good compression and spark tips look ok, no oil or green AF contam, then its fueling or a sick ECU.
Ever check caps in the ECU for leaking or cracks? or Rubycon name? on side.?
power in spurts?, so, is it bogging in spurts, or misfiring. bogging is gentle ,misfire is violent.
which car Red or Blue? or white. I guess RED.
if 2 door Red does this , the ground behind the left rear tail light needs checking. fuel pump ground.

http://www.fixkick.com/power-index.html

diagnosis...???
id need more about the jerking, more information.
when you get the jerking, does moving the throttle fast change it.? in Any way?
Do the spark plug tips look odd?
Is it really a BOG, or is it really MISFIRE, (this is the key fact)
Jerks>
( fuel pressure loss, is a very unique feel, its like a slow, loss in power. the pressure drops slow. but if its spark related, its INSTANT, loss of power. for 1 hit of one cylinder or all 4.
Misfire, it's heard, and felt. or seen at idle , by looking at engine shake.

when it does jerk, a fast right foot change the length of the jerk ,or ends it or no change?
i dont think it's a bad engine. (runs ok most time, so is ok) (this assumes the crank pulley nut is at 94ft/lbs, if not all is lost. anything possible , symptom wise is not.
i think it's bad spark or fueling.
The ECU is not showing errors, so I think that the CMP and spark read back is good, it will report 1 misfire in 10. DTC, 41/42's

How slow can you go and get the jerk, does it ever happen, in neutral. does engine ever try to stall,? or close.
ON flat ground jerks?
or going down hill ever?
uphills, yes.

keep in mind a bad ECU can cause 3 major things fail at once, spark/inject/fuel pump. one or all. lost on the fly.
Usually if the ECU messes up. the 12 flashing cadence, breaks step. its halts mid stride., this is the ECU rebooting, fast.
and the Corner big cap, is top , offender. in fact some are vibration sensitive, and short randomly. (PRE 96s, only)

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on more test.
i have connected a timing light to a spark plug wire.
then taped it to the windshield. (in one case , i removed the hood of car, (yes, motivated)
and then taped the trigger, closed, the strobe is flashing on the glass, left to right away from my eyes. I love Duct tape too...
i drive.
car misfires. i see my lamp (strobelamp) never drops cadence. or I do.? Not is lost fuel, does drop is bad spark.
i can repeat this on all 4 cylinders.

Q2: You're not running those, 3 way plant-able rotors from china , are you?

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the above test , supplants the 1996 white cars, OBD2 misfire detection, the other 2 are OBD1, and cant report misfire at all.
there are other DIY test, one guy sprays water on the spark wires (only), if it misfires. they are bad. get NGK wires, they will pass the water test.

[stickerbuoy]

Yup, as always, the red car.

Plugs were put in without modification. I'll have to find the model number. It was whatever the computer at the store suggested...

ECU was out not too long ago and everything appeared pristine, including caps. Error code 12 has been flashing away for many months now, with no sign of stopping or breaking of rhythm.

As for the jerking sensation, I described it detail earlier in this thread, but as a quick summary, it is sudden, not gradual. It's fast enough that I can't adjust the throttle while it's happening. As far as I can recall it has never happened at idle, but other than that it seems independent of engine speed.

Not sure if this is related, but engine will sometimes stall at idle. This usually happens after I drive to town, turn it off to go grocery shopping, and start it again. When that happens, I rev it before I put it in gear, and usually that lets me get going.

Distributor is stock as far as I know...

[fixkick]

most plugs are set for cars with super, high energy ignitions, wide,
this car is no anywhere near this level of spark energy.
the egr valves log to stuck open as you come to stop., this is because (sure its dirty valve) but happens as you come to stop the idle switch closes, and the EGR is commanded off line.
if the EGR sticks now , the engine stalls or goes to 500rpm and stumbles badly.
the EGR loves to stick on most old sidekicks.
at times it can be a real pain.
i think its got 2 problems now.

ok , like someone grabbed the crankshaft, sounds like total loss of spark to me. random.
that can be hard to find.
check the 3 ECU fuses for no corrosion , on there tips. IG coil, Dome and FI fuses.
dome wont cause this but is ECU fuse for memory.

the not responding to fast right foot actions, tell me it's not fuel.
The fast right foot sends excess fuel fast, via the injectors. NOW. fast, instantly.
if the fuel pressure was zero, at that moment, sure, but sounds to me like spark.
If the fuel pressure drops low and you will sense that first, but spark loss is NOW. like, Paul Bunyun grabbing the crank.
but who is doing that , the Dizzy?
id check connections to the DIZZY , make sure it's side plug is not loose.
and those extra grounds to it.
seen here
http://www.fixkick.com/Good_Bad_Ugly/com...lures.html

see G109?
see that right side of that table. see comments and what those do? 16v 95.


i think your DIZZY is dropping spark,. but don't know way. if the dizzy is dropping off line, code 42s should pop. or if ignite fails, code 41.

one other trick i do on some hard cases.
is to run a small new vacuum line to the plenum, to the EVAP nipple there and in to the cab.
and fitted to my propane torch , nozzle off, then when it stalls, have a helper crack open that propane valve, if this ends the Bad Event its Fuel if not spark.
easy huh...?... and very simple to do..
add fuel at the moment.
snake hose through the fire wall, keep it fitted to tank so it can';t suck air. (no nozzle does that)
what do you think? we do this all the time on engine, hood up and it stalls off idle. (ah lean your are, this cured it)

---

ps. and propane is a very very safe test fuel, unlike wet fuels.

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your car has demons, lets kill em.

[cosmic_splatter]

fixkick, you mention getting mag wires. I'm seeing prices about double normal wires. What do mag wires do for you? Are they worth double the price?

[fixkick]

mag cores never fail.
and are 2 and 3 layer of silicon insulation that last bloody for ever.
but i run bosch ok, but i lust for NGK, they are the best. best is to wait for on sale , like on ebay...

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the bosch mag wires are just great.
and go on sale more often,

[cosmic_splatter]

I see the bosch part for trackers is...Bosch 09360

NGK is 8120, SE94.

I just bought a set on Amazon for $50. Hopefully, they will last 100k miles!