96 Geo Tracker p0300

[wesleyc]

Hello jtgh & all:
Well I replaced my timing chain and water pump (as preventive maintenance cause I'm in there already) and the engine runs exactly the same, pretty steady at 5 deg (with jumper on between 4 and 5) and then without the jumper advances normally except that is coughs terribly upon acceleration, stutters upon acceleration dies most of the time upon giving it gas and generally runs badly. I again had to advance it substantially manually to get it to be drivable. I suppose I should check my fuel pressure next, although why would it run with decent acceleration in this advanced distributor position if the fuel pressure were bad. Wouldn't it be the same crappy running in any ignition position if it were the fuel pressure? I am baffled.
Also #3 plug had been partly stripped, likely due to someone in the past not finger tightening the plug. I had about three threads left from what I gather, but now that I have removed and re-tightened the plugs a number of times, this last time the plug wouldn't come out of the plug channel. I suppose there are methods I could use to correct this. In the mean time it's not losing compression from what I can see even though it isn't totally tight (I removed the plug compression washer in order for it to tightened the last time at all).
Anyway that could be dealt with later. For now, I can't seem to get this engine to run right. I'm back to square one.
Any suggestions would again be welcome.
Thanks,
Wes, Oak Park, Ill

[tracka96]

So - When you were into the water pump, how well did you check to see that the timing pulley hasn't moved on the crankshaft? When mine was bad, the only way I could really drive it was to advance it to about 18 degrees, not uncommon. Tracka

[jtgh]

you either have a real timing problem or you actions are hiding something more fundamental.
1996 Sidekick 1.6L 16 valves .

DO YOU HAVE A DISTIBUTOR with CAP and 4 spark plug wires ( some 96's have COIL ON PLUG)?
DID you do a tune up, I heard you say they are ok , i want to know if the cap rotor,wires and plugs are all new.

in my younger days, during trade auto circa 65' we had a spark plug testing machine.
this device , demonstrated that IN FACT , the higher the cyclinder pressures the more likely the plug or wire (carbon) would fail.

retarding the timing will cause the spark to occur during lower cylinder pressures, in fact it becomes easier, but that is a red herring, because the
Ignition is failing, not the engine. do you see. do you see how easy it is to fool ones self in this area.?
Spark plug wires can LOOK perfect and in fact Be bad. (some are only a nylon string with carbon dust and very prone to failure) CHUCK EM.


P300 means bad spark any cylinder OR weak injection OR low compression on 1 or more cylinders.

The problem is to find which is the correct direction to take.
DO YOU HAVE COIL ON PLUG ENGINE ? ( id dont think so, but tell us)


while doing a any Timing belt swap on any sidekick, it is very important to verify the crank cog gear NUT.
verify the torque is at spec,
put gear shift in 4th or 5th gear, chock all wheels.
then try to set the nut to spec. 65 ft.lbs
that # is for a 91 , look yours up !! for 96.
if it moves, that is a strong indication that some one else set it TOO LIGHT.
If it moved even a little bit, I'D pull it off and the cog and fully examine the crank end. the key ways , key, etc.
Option2:
an alternative to this is to re-degree the crank with a piston position device and check that the crank pully tab aligns perfectly with the
TDC marker at 12:00 just above the crank on the case.
But the former visual, is vastly superior.!!


Any one else reading this , please validate your cranknut on EVERY
Timing belt swap. Always set it to the high end of the spec with locktite. some even put loctite on the key and crank end.
Some even replace the seal and call it done forever.

your car should NOT run better with the timing set wrong.

your right the FP is ok.

sounds like you need a sparkplug hole heicoiled.

[wesleyc]

To Tracka96:
Apparently not well enough. I thought it was perfect. But I should have triple checked. Now I wonder. I thought I was pretty careful. I may have to do this job over???? I hope not.
To jtgh:
Cog nut is not spec'd but it was extremely tight and I made sure. Of course, if I'm not diagnosing the problem correctly and for that matter any of these associated problems, then how good could my cog nut inspection be? I've got to say that all is well and that the cog is really tight and motionless. I put a lot of pressure on it when installing the belt and really immoble. I will check everything again tonight if there is light but likely tomorrow. Would the crank sensor always indicate bad on OBDII if it were in fact bad or can no crank error show up and the crank sensor still be bad? I don't think that's it, I just thought I'd ask. I personally don't feel as though I've missed something in the assembly of the pump, belt, pulleys etc. Is there any other possibility, or do all of you really think that I in fact has mis-assembled something.
Let me know, and I'll be writing back.
Thanks as always,
Wes, Oak Park, Ill

[jtgh]

I want to start over.

is your ignition parts all brand new, Fresh ?
rotor,cap, wires, plugs?
Yes, or no?


before we go futher we need an answer to this.

as we all know, P0300 is 99% of the time, bad ignition.
for the other 1% we work harder. (injector? , bad valve ,ECU, etc.)
but we would be crazy ? to no put IGNITON to bed.

all we have to go on is your statement:
"The plug wires are alright and the plugs are in excellent shape." < i do not know what this means.

1- they look good
2- they are brand new and are of quality brand name.
3- I replaced them 60k ago.
4- I have no idea.

[wesleyc]

Hello jtgh:
Man, I can't express enough the appreciation I have to you and your site for the guidance I'm getting in resolving this issue. Enough said for now on that, but it's great.
I have distributor, wires and plugs. I too thought that the plugs could look good but be bad in fact. I had this once on a car that a neighbor brought to me to help get running years ago. It was an 81 Honda Civic stationwagon (or so) (great little engine, I ended up rebuiding it to get the car running). But in the process of trying to get it started after rebulding I'd replaced the same set of plugs that it was brought to me with. They looked great with virtually 100% electrode. Of course the engine wouldn't start. After a ton of diagnosis thinking I failed somewhere in the rebuilding. I decided to change the plugs and voila the engine almost instantly turned over. I would have never suspected the plugs. So I applied that experience to this as well and the other night before I took on the task of changing the timing belt, I bought new plugs and installed them. NO DIFFERENCE and still ran like s__t. Now on the subject of wires, cap and rotor, they also look really good. I suppose replacement is in order, along with the coil. I have taken to heart your data on the relationship between compression and spark. It could be the whole problem. If it is, it would then explain how the old timing belt was also right on the marks even though it was slightly stretched but in very good shape, and therefore likely still timing the pistons with the valves pretty darn well. (I sometimes think that when the obvious is staring me in the face, I do something else because I think it is too simple to be or not be the problem. I mean when I saw the belt and the timing marks and all was OK I should have presumed that those components were alright and not suspect that a bit of stretching could be causing such a poor running condition. I think that I am lacking the ability to perceive the obvious) And my resetting the distributor the other night to be able to lock the distributor in a position which allowed the engine to run decently, was supposed to be temporary, but may have been actually an inadvertant repositioning of the distributor to factory specs cause the previous owner had already reset the distributor to make the car runable (sounds farfetched, so not sure of this). Anyway, I will do what you are implying, and that is to not take the condition of the dist, coil and wires at face value. I will first test resistance of the wires before I replace them, but as to the coil, should I simply just go ahead and replace? I wish that the average garage mechanic like myself could have access to meters like one to test high voltage at the plug. I do have one from the old cathode ray tubes when I used to hobby in TV repairs. Hmmm?
Lastly, I was thinking that there should be an easier way of checking the valve cog with its mark in relationship with the crank cog, and I decided that this could be done and I am going to try it. Rather than taking the valve cover off to check the position of the valves in relationship to the crack, I am going to take a simple 1.25" hole saw (I have been a finish carpenter most of my adult life and eventually evolved to home rehab, then condo conversion, but stayed very little and still do my own moldings etc.) so I think I can accomplish this without damaging the cog or belt. The hole would have to be drilled carefully so as not to get too much plastic debris in the bottom of the gear area. I think that could be done by letting the hole saw drill only to the point where it about to break through and then let a utility knife cut the balance. Then placing a Plexiglass site glass in its place with two side screws for easy removal (keep the screws small so as not to interfere with the belt and gear), or not even need a clear site glass but any kind of solid plastic (relatively heat resistant) would do. When you would need to check the cog position, all you would have to do is slip this inspection plate over and let one remaining screw serve as a hinge. This way I could always know where the cogs are at. Am I turning something simple into something very complicated. Maybe. OK. I'm going to do the ignition components next, likely tomorrow night, and let you know. By the way, if this fixes the problem or at least eases it up, I still won't get why the engine would run best in a very advanced position and not in spec.
Thanks
Wes, Oak Park, Ill

[jtgh]

WIRES: can have weak spots that change resistance while engine shakes, which feeds more shakes.


Cap and rotor. they get hairline carbon tracking, some so small that no one can see them.

Test the coil: ( it will be good , my guess)
ok. plug a sparkplug wire and plug directly into the coil , and Sparky case to block ground.
someone cranks, you look, if fat blue white spark , then coil is ok. IT will be fat !! and dont touch or you will learn wingless flight.

plugs, yes, the insulators can get contaminated and they look all the world perfect but in fact are crap.
it doesnt take much contam, with 50,000 volts.

as the pistion comes up to TDC there is less pressure.
same going away on a misfire (think that thru)
and if you set the spark to that point that is at low pressure AND the spark is weak , it may in fact fire.

Now as you advance closer to 0 TDC the pressure is max. and in fact the plugs LOVE to misfire, right at the point they are needed most. " and accident of design"

That is way most mechs, never blink when they get a p0300, IN goes a tune up.

Spark , Compression, timing and fuel.

The rationial:

spark: tune up cheap and easy.
compression , easy test.
Timing, a little harder (cam and ignition)
then last we play with fuel. ( is your gas fresh?)

some questions may seem dumb, but we cant see it or know its history.

this is a very old car.
it could have a minor, slow headgasket leak.
it could have a burned valve (minor)
it could have lots of issues.

when you drive this car, does it.
backfire, or pop back thru the Throttle body?
does it CUT out ? goes good,then bucks,
does it small like its running rich? black exhaust and stink !
you said loss of powe,r but just weak or does it act up?
tell us more.

[wesleyc]

jtgh:
Good logic. I understand.
Car backfires and pops when at spec, but when I advance substantially, it idles badly but runs pretty nice except for studder upon deceleration in gear. Overall pretty good power in advanced position without miss.
Car has 107k, but overall seemingly taken care of, except for top whose seams almost entirely decomposed (I resewed them by hand- took a while).
I'll let you know when I change the dist cap and wires.
Thanks as always.
Wes

[jtgh]

Reflections:
back in the 60's
no one changed oil or tuned up. (so it seemed)
they drove them for 3 years and sold them.
many drove them until the points were completely vaporized !!!

many , fiddled the DIZZY and drove another year.
cars brand new for $2k ( disposable) what an era!

one guy here , just found out the car he bought , the PO put in a Tbelt , WRONG.
so he was doomed to start.

with a new car in the barn look carefully.

one new one in my barn 96 had funny braking.
pulled randomly and in random direction, Hummmm
on careful examination , the brakes were perfect.
but some Numbskull put caulking behind the pads.
It had hardended to nails. and was all over the guides .
After cleaning it , the brakes are perfect.

I hope you find all the surprises your PO left you and with little trouble ! good day.

[wesleyc]

jtgh: You are so right!
So I went to change wires, rotor and dist cap today and in removing the old wires I discovered that they were not installed in firing order by PO. They were 1,2,3,4 instead of 1,3,4,2. So I corrected prior to changing the ignition components and the car started running at idle without the misc stutter, and random misfire, except now with a clear and solid miss in only one cylinder. But it's the kind of miss that one would see in a bad plug or bad valve. Very distinct. So I changed the rotor, dist cap and rotor but no difference, still one very solid and distinct miss. I thought it was the #3 plug which is partly stripped, but it got too dark to work and so I'll wait til tomorrow. I got too late of a start today. This is making more sense now, and although I may have done a lot of unnecessary work, I guess it would have been required at some point, unless of course a valve is burned and the head needs to be removed anyway. However, this is still pretty p**s poor diagnostics on my part. I should have checked everything thoroughly before I started the timing belt work. I would have never thought that a previous owner misplaced the sequence of plug wires especially since it ran at acceleration without a miss and with decent power.
Anyway, I now do have the distinct miss instead of a misc miss, but I hope I'll be better at diagnosing this one.
Don't quite understand how it could have had decent power upon acceleration (with a severely advanced dist) without any serious miss with the wrong firing order, and now with proper firing order, there is a solid one-cylinder miss. I think I was better at diagnostics when I was younger, perhaps more patient.
Thanks
Wes, Oak Park, ill