Engine slight "shiver" at idle- normal?

[Vitalie]

Ok, while I am waiting on parts to fix my speedometer I will post here something that seems not right to me. I noticed that at idle with all the accessories off my car "shivers" very little but enough to feel it at about 5 seconds interval. It feels like a little kick or something.

Here is what I did for tune up so far:
New alternator (the lights were flickering and the car was literally hopping in traffic)
New timing belt timed by spec.
New air filter
New spark plugs NGK gaped to 0.28
New spark wire set.
Cleaned the throttle body and the EGR channels (440 gone)
I checked the timing is set to 5'

I ordered a distributor cap with rotor that I intend to replace but so far nothing changed from before the tune up begun.

I posted a on YouTube something I tried to catch the problem on video. http://youtu.be/NTkipnBrrx8

Well at this point I am leaning towards that is normal. What do you guys think?

My car is the chevy tracker 98 2wd, 4door, 16v. 5sp
Thanks

[fixkick]

that vid. is set to private, so link fails.
shivers. (is this in neutral?)
hot or cold engine or both.
is RPM hot 800 , plus or minus , 50 RPM?
does RPM hunt , at any time hot?

is shivers, RPM variance< or a sound only, ?

this car has automatic, IDLE controls. and will hold idle tightly, hot.
one test hot is thrown on A/C , blower to high then, head lights then rear defroster. at once to see if RPM goes way low. (and sticks too low ,or takes 1 second to recover)
it must hold 800 hot. if not the ISC system is failing. (that dont mean its bad, just that it can't handle some problem with air or fuel,etc)
the idle will not work if the Idle switch in the TPS is bad or set wrong.(calibration)
a voltage test at the TPS solves that riddle. fast. backprobed.

if the shiver is sound only, not RPM surge, its most likely the tins, near the CAT making noise, or loose exhaust manifold shields. or something else loose but is not normal.

[Vitalie]

that vid. is set to private, so link fails.
fixed it and added one more for gauges.

http://youtu.be/NTkipnBrrx8

https://youtu.be/dJ_Jnc3JjNM

shivers. (is this in neutral?) Yes
hot or cold engine or both. Only when hot and idle at 800 rpm
is RPM hot 800 , plus or minus , 50 RPM? Yes
does RPM hunt , at any time hot? tachometer moves a little while I feel that shake.
is shivers, RPM variance< or a sound only, ? I can feel it, hear it and see it on tachometer.
this car has automatic, IDLE controls. and will hold idle tightly, hot.
one test hot is thrown on A/C , blower to high then, head lights then rear defroster. at once to see if RPM goes way low. (and sticks too low ,or takes 1 second to recover) the rpm jump to 1000 when AC on
it must hold 800 hot. if not the ISC system is failing. (that dont mean its bad, just that it can't handle some problem with air or fuel,etc)
the idle will not work if the Idle switch in the TPS is bad or set wrong.(calibration)
a voltage test at the TPS solves that riddle. fast. backprobed. after all additional info you still think this has to be done , I will need more info how to do it.

if the shiver is sound only, not RPM surge, its most likely the tins, near the CAT making noise, or loose exhaust manifold shields. or something else loose but is not normal.

Thank you

[fixkick]

it's misfiring. hot.
lots causes.
bad spark, is #1 (injection 2nd)
is that timing belt fresh at last 60k mark? or still original/?
cap and rotor. sure can be bad ,
try Techron injector cleaner, it has benzene that can clean very dirty injectors. and cure misfire.
with a scan tool connnected, is the ECU/PCM holding closed loop ? at idle?
and what is LTFT ? long term fuel trim, near 0" or way off in the woods.
DTC codes stored? any live, stored, or pending? scan it.

id put a new front oxy sensor on it, to get longer term MPG, (payback) an the 02 on this car, does work at idle. (if no exhaust cracks)


any dirt cheap scan tool works on this car.

[Vitalie]

The timing belt is brand new. (Just to mention that the spring for the tensioner was missing when I did the timing job. I did my best to make sure that everything is aligned and tightened properly to the marks)

As for the fuel treat I did the little Lucas bottles twice in a row.

I don't have a scan tool but no engine light now. Though I had 2 when I got it. 440 and 400. 440 gone after the EGR cleaning and 400 was more of a challange but changed several gas caps and it is gone too (thanks God) after several mechanics start broking my car and try to charge me I said Thanks but no.

About fuel economy I get 300-330 miles per tank and I probably still have half gallon left , 50/50 traffic/ highway.
I was thinking that is good. Will think about O2 sensor along the way.

I have no clue what is LTFT and how to check it.

One extra thing to mention not sure if related but the butterfly in the throttle body got pretty dirty after just a month or so after I cleaned it, I thought that is odd. The sparks tips looked normal though just a bit gray but dry.

Also when checking the timing with light I noticed that it is steady at 5"and then I thought I saw it at 0 . At first I thought it is a mirage but kept the the gun longer and it happen 2 or 3 more times over the 3-4 minutes I performed the test. That was odd too.

Anyhow will change the cap and rotor next as it is on the way but very appreciative for all the suggestions. Sometimes it feels there is no end of it.
On the positive note I have a blast with this car with all the problems it has.

Thanks

[fixkick]

sorry the scan tool lets us know the engine is running in closed, loop, if its not, that will explain the misfire. Even a $9 tool works.
and the LTFT this tell you , (scantool) the long term fuel trim, this is parameter is for how far off the fueling , at idle if done at idle. If way off that too explains, misfire, (too rich or too lean)
The EGR cloud and PCV clouds, of gases. collide and form gunk inside the plenum on this engine all the time, it a service issue for sure.
just make the valve free, is all.

lots of things can go wrong on such and old car. Even air leaks, or just a dirty MAF sensor.
EGR leaking? both it and its piping , or missing EGR gaskets, (causing side air leaks) in 3 places.
The 0xy sensor must work


LTFT, runs PLUS or minus around 0. 0 is perfect.
most good cars run -5%, that means the Air fuel ratio is naturally rich a tad (safe side ) and the EFI oxy readings correct it to perfect Air fuel ratio. AFR.
if it reads like -30%, that means its grossly over fueling and correcting it best it can.
if it reads +30% (lean) (that means 1 of 2 things, the MAF is dirty, or there is a huge air leak in the intake and great danger for engine if ran at full power lean. "ping or knock damage"

the CEL only tells you, the car is failing for smog, it is not a status light, that the EFI is and running right. In fact I ignore it , and just scan all cars.
and the newer the car, the more you must do that with 100s of errors possible.

no matter what its a runner... good luck with it.

[Vitalie]

updates:

ok
changed the cap and distributor. Did not see much difference but I will have to probably change a bit the headline as after some more tests I did.

When I got to work this morning I parked and with the car on I watched for symptoms. Well, I will feel a little shake as usual 3-5 seconds apart. the engine is about 800 rpm.
Then I turned the AC on, it when to 1000 rpm. but I will not feel the same shakes as with the AC off.

Next I turn the AC off and got my rpm to 2500 and held my foot steady for a while and guess what the car will give a little tremble also every 5 seconds, the same to 3000rpm.
but I don't feel these with the AC ON.

Also when it gets to 2000 rpm I notice a change in engine sound and gets back normal after 2000 and up.

strange?

Thank you

[fixkick]

ive heard of shiver me timbers but this?
LOL !!! and welcome back.
my guess is that cyclical action, is the ECU trying hard to correct this.
Keep in mind, a scan tool can show many errors, some of which newer glow the CEL. at all. and in Canada less. (on some kicks, like 25 things) never fail to scan, at the first odd engine symptoms..


it's just misfire. the causes are many.
misfire is bad spark , bad fueling or bad engine compression. the 3 classics.

is spark timing right?
is the rotor not on the wrong way? one way , can allow the rotor to cross fire cylinders, the the other (1 of3) wrong ways kills all spark.
injector leaks or clogs.?
(most oxy sensors are past their prime at 100k miles, for many reasons. and are cheap parts, like $50 or $20 for generic)

O2 sensor slammed lean (exhaust leaks near it) causing ECU to slam fuel mix rich and it rich misfires. (super easy to see even with a $9 scan tool) you see say pending p0300s, and dead 02 and LTFT way off.
the O2 , is the driving force to the LTFT. (if the 02 lies, so does LTFT) The key word there is trim, what if the silly thing trims in the wrong direction, I'm all over that bad act...

weak compression on one cylinder can make it misfire. the ECU injects for fully good cylinders (a shared 02 is reason). (a weak cylinder goes rich and misfires.)
a leaking injector causes misfire, and will make them all misfire due to Oxygen passing fro the intake (unused) past a dead cylinder to the 02 sensor, causing it to lie like a dog. (false lean) (the ECU never knows fuel mix only OXYGEN)
IF the, Intake air leaks real bad, can cause lean misfire, but not at 3000 rpm. (the leak become tiny, in the total huge flow of air....)
the AC on ,just tells the ECU to go to fast idle mode , nothing more.

Your engine is misfiring at many points in the RPM load curve.
Id use only idle misfire in my ATTACK, because why?, it's easy, i'm not moving, it does it over and over and i can fix it. finding under load misfire is vastly more hard and complex. (and some risk , use 2 persons to do moving checks)
but at idle, the 02 must work right, if it don't?, it will misfire, especially if the 02 is fibbing, (it can help or hinder. that is its deal)

on my 96/97 the O2 come on line fast in about 15 seconds on a warm spring day.

keep in mind the 02 drops out , accelerating and going up hills. (load) So that is why it misfires only with static RPM and no loads. It's because the 02 is ACTIVE. At idle and light flat cruising..


my scan tool has this.

http://www.fixkick.com/ECU/Authority/A_F..._scan.html

oxygen sensor closed loop status (CL or Active)
see that. that is the 1st thing i do.
see me do it here (link above), step by step, my checks.
the ECu tries hard to get the engine at STOIC (no smog) and trusts the sensors. If the sensors fib, the ECU will in fact mess up injection or even make it worse. (02 sensors love to do that worse thing)
you see it misfire, that is its way of crying for help. it will get worse.

key causes, advanced.

1: exhaust crack near the front 02 sensor.
2: the exh. donut gasket bad, (more are by now, shunk or pound to death flat and leaks)
3: #4 exhaust tube cracked (02 will be dead, (even if good) for leaks.

---

amazing it not enough to make front 02 go nuts yet but will soon.
i 'd get this. the CALmini,

only if cracked any only if it effects my 02, as it surely will soon.
http://www.fixkick.com/buy-parts.html#calmini

[Vitalie]

i got the OBD II scanner for my phone.
I did some scans last night and this morning and the

idling:
fuel System runs in closed loop pretty quick after start with O2.
after warm up there is no faults pending or active. the Emissions readiness are all complete.
the timing is 8-9.
the MAF is 2.1
Intake psi 4.2
the LTFT is a bit strange it started at 2.3 and while idling for 10 min start moving in steps every 2-3 min till it got to 7.
the STFT is -1 to 1.3 or so.
Vacuum 21.7



on the freeway:
timing was jumping between 30 and 39.5 even on steady speed 65mph
LTFT was about -1.5 or so
I think the MAF was about 12

Excuse the ignorance I am just starting to learn more details about the car.

Thanks a lot.

[fixkick]

your doing great, really good.

the timing will change greatly with load, more load, less advance and but faster RPM with light loads, more advance.
all looks ok.

your shiver surge is preplexing?
just a sticky ISC plunger? it sticks a bet ECU over reacts, and corrects?