(06-07-2022, 04:00 AM)sina27 Wrote: Hey guys
I have a 1996 geo tracker 16v MFI, 2WD 5 speed.
I have a new CAT but I'm failing smog in California due to high HC. Everything else on the smog report is passing with flying colors.
I've put in new spark plugs and wires, new sensors, new dizzy, did timing, etc....I think its running rich during idle only...which is why Im seeing high HC on the "15mph" smog report.
A mechanic told me based off the smog numbers that it could be because my spark is weak.
I tested a plug for spark engine cranking, and it looks like the plug is firing weak (I see an orange / yellow spark - not a bright white / blue spark).
So I changed my distributor with a new one...same thing. The dizzy has the integrated coil and ingiter, so I assumed that would fix my problem, but nope!
I also changed the CAS sensor under the oil pan. NO LUCK.
What else could be causing weak spark? Noise Supressor Filter?? I have NGK plug wires which are 6 months old so I dont think its that.
Could it be the alternator not producing enough current? During idl, the battery reads 14.3 volts, so my alternator is good - right?
NGK gappped to 0.028" not factory 0.045 " ever, they must be gapped correctly., this Distrib is not high energy until 1999 .
well he guessed wrong, a real mechanic would say he
would do tesst to find this problem
not done, is the thermostat new? and water temp at 180f all the time warm engine? scan tool, ECT 180f or more. never less.
at idle is ECU in closed loop at ECT= 180f? and if you race idle to say 2000 RPM and hold it there with rock steady right foot , Closed loop (CL) active, if not that is bad running.
and if is open loop hot at idle or at 2000 rpm that is, bad, sure it can fail smog.
are all smog, statuses time out, and CEL lamp only glows key on and never running./
there is lots more, and are not guessing it is testing for each case using tool, any ASE shop knows these steps.
1: engine passes compression test, 180 psi, x4.
spec is (new) The 16v is
195 PSI. Seen in FSM chapter 6-6 (not 6A1) Facts.
if way low the cam belt has slipped. do run this over 60k miles and then it slips? retarded cam wastes a ton of fuel and make ECU go mad. (try to make bad good)
2:injector leakdown test, if they leak they will fail smog. (pro clean them?)
3: spark timing way off not using the timing freeze jumper?
4: bad front O2 sensor , never swings and never goes to closed loop, (rear 02 does not set mixture, it only checks cat for good cat)
5: exhaust leaks anywhere near (2ft) of the O2 Front sensor, I use scan tool real that I can loop the o2, scan test and see it swing correctly at about 6times second (closedloop) and NOT OFFSET, to lean. of you have leaks it goes way lean and ECU injects huge rich wrong, (02 sensor must not lie or the ECU will inject wrong.
6: bad maf, or china cloned maf put here, and is hopeless as can be, the stock maF has a number on the side.
13800-
58B00
never seen a good clone from china ever, me. all are crap, pure. best rebuild is from Cardone 1. USA (prime source ) my MAF test page covers all that in depth. fixkick.com
http://fixkick.com/sensors/92-95MAF/92-9...sting.html
7: FPR is bad, this is super common now. 26 year old FPR, think the millions of times the poor diaphragm flexed for 26 year, how can it be good well the test is easy .
using a vacuum hand tool and fuel pressure gauge or just the FP gauge. my FPR page is here , easy test.
in the same vein, fuel pressure not correct, even stuck at 50psi is dead to rights wrong, FPR bad , return ling clogged or wrong fuel pump on car off a V8 engine? one guy here had crown victory pump mounted outside the fuel tank and gets 15mpg. all the time and red not glowing cat, he removed after it melted, so yah, lots old cars have wrong parts. dead wrong./
http://fixkick.com/sensors/tests/FPress-reg1.html
2 tests, keyon no start and idle PSI of both pass the PFR is good, and at idle it must not surge PSI and the vacuum nipple must never leak fuel.
8: a real shop after all the above would measure HC before the CAT and after, to see if the engine is super rich so bad no cat on earth can eat up that HC raw fuel.
he puts a tap in the front header. exh..(tHAT DOES NO LEAK AIR) KEEP IN MIND THE EXHAUST BLOWS AND SUCKS, AT EACH CYLINDER FIRE,
9: SCAN TOOLS, ALL HAVE WHAT IS CALLED A BUTTON CALLED PENDINGS, no P03XX CODES THERE, NONE!
AND O2 SCAN, acts like a 02 meter. and show the 02 signal (front swing like this)
like this, at hot idle or at light cruise, or just in Neutral, 2000 rpm hot this is closed loop seen LIVE
ors/O2%20sensor/O2b1s1.jpg
good luck and cheers./