compression on that cyl. match the others.
swap spark wires.
swap injectors (and listen to them with rubber hose in ear for equal sound on all 4 )
make sure distributor is perfect.
OBD2 will show your fail only with pending's and live data. the CEL (lamp) is pretty useless for
go /nogo, it only comes on after smog is over 50%.
Gross fails .
OBD2 is your friend. it can tell you many things. if you look
if motor and spark and injectors are prefect
it might be just pure rotten leanness.
i cant drive it nor feel it but.....
short duration hesitation can be bad TPS. (this allows acceleration to be fast with fast right foot)
long duration can be bad MAF or low fuel pressure.
(im sure not yours ,but..)
many people have pulled hair out ,and checked everything, including live data stream obd2 data and could not find the problem,
and then discovered a broken valve spring (passes compression tests)
on the car ,id never trying to do anything with out a full scan tool.
you can watch the O2 , see of it goes closed loop quickly from cold.
see that CL holds ,at idle hot.
and that it holds ,at cruise. (it will drop on WOT or fast right foot, naturally)
id also never try to fix any EFI system that has hesitation, with out first checking fuel pressure when the hesitation happens.
if that takes duct taping the gauge to the drivers side wind shield ,so be it (hood removed)
the EFI systems is completely useless with low FP pressure.
we had a guy here last year that had a FP that drops off at 3000 RPM only.
well, he could not exceed 3000 rpm cuz underloaded, and sure enough , 3000 rpm in neutral and more was not problemo.
could a bad injector cause this kind of intermittent problem
truth is anything can, there are common things that can happen and then the rare.
best is keep open mind. and do test.
The OBD2 allows me to look at short term fuel trim too, "STFT"
and i can watch in real time if motor is Lean or rich.
invaluable tool it is , a full scan tool
STFT is a plus and minus reading, -20 -10 -5 0 +5 +10 +20 (perfect is slightly rich, real,so scale will be slightly minus to reach stoich.)
EG:if the motor is running rich , it reads -10 .
keep in mind if the 02 is lying (offset do to age) then the STFT will be lying too. << very very important.
id never do any testing with out a fresh front 02 sensors.
after all , all the readings will be based off, that one critical part ,the o2 sensor.
lets say it reads 10% rich, (in error because it is bad. or age drifted.)
then the ecu simply subtracts 10% fuel (wrongly). so now your motor is running at 16:1 AFR. (too lean real)
what you are missing, is the truth , what is the real AFR when the motor misfires.
is it mis-firing due to lean or loss of spark?
there some old fashioned ways to find out.
i place my propane injector hose (home made) into the evap nipple on the plenum.
i drive , small propane cyl. in lap.
i drive and if it misfires , i crank the propane , bingo ,
no change, must be spark
corrects misfire ,bad fuel injection .
those are my ideas, there are lots of other tricks but since i cant feel your car
and drive it hot and cold and try to over load the fuel pump cold.. im mostly guessing.
key is first finding out which it is, (keep in mind lean motor causes spark to fail)
I finally took the car into a shop for them to scan and diagnose the problem. After a couple hours, they determined that the tps was bad. They couldn't find any other problems. Their diagnostic equipment which was supposed to be comprehensive, did not have Tracker specific information, so they could not say for sure that the tps was not working, but when they drove it with the tps unplugged, the hesitation more or less went away. I can confirm that it drove better with the tps unplugged, but not quite right-not surprising. I had already tested the tps with the sweep test and on the car using my fsm specs and it checked out fine. I'm not completely convinced the problem is with the tps, but that the ecu is compensating for the unplugged tps and somewhat covering up the real cause of the problem. Is it likely that the tps could pass the tests I administered and still be bad? At at least $350 for a new one, it is a lot of money to spend to find out it wasn't really the problem. It's hard enough to find a new one in Canada, so I don't think I could find a used one.
97 Geo Tracker,5sp, 4wd, 16v, Canadian
first of all , driva8ility issues are the most hard to find.
yes the tps is num one reason for tip-in hesitation.
if the pot is worn it will happen randomly and then get worst in time.
8ut egr will cause idle to drop 8elow 800 rpm
the 97 must hold closed loop , after warm up , at idle.
if you move the throttle fast , i assume tuned up here and good fuel pressure,
the tps sees this movement and enriches the motor,
this is 8ecause the MAF is slow to react.
so you get a mini 8og and the MAF then catches up. ending said 8og
sorry my 8ravo key is INOP.
the TPS is 175 dollars 8ut with la8or then more.
the disconnecting of TPS
this is easy,
all cars mimic the tps when disconnected.
how does it do that, simple, it uses only the maf and cmp speed up.
it does a lousy jo8 of this and can also 8og.
this test is good if it helps , find the truth.
there is no way to diagnose a dead tps. or noisy one.
a meter can find it if 8ad
8ut, it has to 8e really 8ad to see it.
i forget , are you getting p030x misfire codes.
and yes they do allow low level fail 8efore the CEL goes and sets the dtc.
yes 50% increased smog is the rule.
the ecu can refuse to set CEL if 49% increased smog.
not if you look at pendings. a real scan tool shows the truth,
if pindings are clean it is not misfiring.
if the motor is running with grossly low fuel pressure.
and can not make full powerup hill , you need to forget tip 8og.
a good tech will drive the car and look of first order fails.
hesitation is last after all else is ok.
if ecu can not enrich, it sure can acknowledge a request to do so.....
Personally, I would try to find a place that has the proper scan tool for your car (suzuki dealer??). We have seen too many people here whose mechanics guess at problem, go through expensive repair, only to find repair does not solve the problem. Would think that on OBD2, your ECU would be specific enough (not dumb like mine) to throw TPS code if this was the problem. I would check all that kick fix says above, fuel pressure, etc., etc. before throwing $350 at a repair that may not solve the problem.
And would have to wonder what the shop was doing taking a couple of hours to diagnose this. ???? Proper scan tool tells you a lot quicker.
8ut these years, the ECU can not warn you of intermittanant tps
only open or shorted.
when the tps glitches , the ecu says to sell, did the operator do that or did the tps glitch. it dont know.
sure it can look at rpm and see it not move and know tps is 8ad
8ut ,, he is moving throttle,demanding enrich and if TPS fails to change , appropriate to the reality of his foot then it
that he move his foot slower.
the result is a 8og.
rimes with dog ,
no 8ee key.
see the ecu would need 2 TPS switches to know the diff.
i worked on high end transportation controls with redandancy, just for this reason.
this equip sends DTC, TPS 1 and TPS2 on cross link failed.
this means they dont agree.
8ut on low end , private cars we dont have any redundancy.
all we have is that we must think like the dump ECU AND TRy to 8e in its shoes with 8ad input.
this is a classic fail.
if if if
car runs perfect and gets fully hot, 180f min. and can 8e flogged hard up a hill with no power loss
if it you can nail the gas and it moves faster , after the 8og,
and the EGR is not leaking, or the AFR is not railed lean
then the TPS is 8AD.
cat is not clogged due to rules a8ove.
the full scan tool must 8e checked for closed loop , running hot.
does car hold CL cruising.
if all things check out fine then the TPS IS 8AD.
THERE IS ONLY ONE WAY TO TEST A TPS AND THAT IS A SCOPE.
while driving and a helpper looking , to see the glitch when it happens.
ALL TPS DIE THIS WAY, ALL.
THEY SIMPLY WEAR A HOLE IN THE CAR8ON. tps pot.
just seeing of 8 key looks 8etter in caps. , kinda..
the tps is just a PoT and as such dies just like all dies. they get noisy
rememer the old days of analog radio , with a real volume control¿
that was a pot
rememer the scratchy sound when you turned the kno8 ¿
that is exactly how a 8ad TPS 8ehaves and for the SAME reason.
its just a pot. full of car8on.
yes, scan it fully and while cruising and check for CL, and lean o2 and short term and long term trim and for no PENDINGS.
and all MONITORS complete.
I finally started tearing down the engine to see if I could find anthing wrong. There was nothing that stood out. I started with the head and worked my way down. I had the valves done(they didn't look too bad), and put in new exhaust guides. On the bottom I put on new rings, but left the bearings alone. Other than that, it was just all new seals and gaskets. Anyway, the car seems to run really nicely now. I have way more low end grunt and it is smoother overall. Maybe it was just the slightly low compression. They were all around 165. I haven't checked them since. Thanks everyone for all your advice.
97 Geo Tracker,5sp, 4wd, 16v, Canadian
troubleshooting ANY car sans tune up , is , well, crazy.
1st tune up the car, then diagnose problems.
all answers , are prefixed with that statement , (implied ) it's the no brainer preamble to all engine problems.
we never waste our time , testiing spark wires, we pull them (just like it says in the maintenance sched) and put in a fresh NGK set.
and NGKs are never ever bad out of the box. unlike fleabay or other stores that sell no name junk wire sets.) " BRAND NAME PARTS "
cap,rotor, wires,plugs and filters.
then we do a compression test
then a vauum test.
then a fuel pressure test.
once these simple tests are done we know the system is viable and can be diagnosed , if need be.
this sets a base line in orderto make tests.
ive seen 100s of times rotors and caps carbon tracked inside where you can not see.
looking at High voltage parts and proclaiming, gee it looks good is the biggest lie you can say to self.
these parts break down from inside. (can)
All ignition parts have a short life span, and never ever last 300k like a motor.
this is why we tune up cars, to get the short lived parts in to the garbage can.
do not bottom fish on ignition parts or you will get burned.
lie #2 as stated here 100s of times.
the fuel pressure test done by the useless squirt test.
all this test says is that the PUMP IS ALIVE, NOT A SINGLE OTHER THING.
if you can not check pressure then find a mechanic that can do it.
the pump feed (elect) power can be weak.
the pump can be weak
the regulator can be bad causiong under or over pressure.
that swuit test is hopeless.
that my 2 main beefs
no tune up
no real fuel pressure tests.
working on any ca with out a basic set of tools, hard. (besides obvious sockets and spanners)
3 pressure gauges (vac, fuel , compression)
1 timing light
propain torch for heating tight bolts or loctited bolts. or to use as test fuel or to find vac leaks ( my gosh it has so many uses for $10)
an OBD2 scan tool.with CAN-BUSS !
$3 sethoscope (DR. type for mechs, indespensable!)
That was stage 1
Stage 2 is
full set of torque wrenches ( you plan to fix the majors)
Impact guns and spec. high impatct sockets.
now the IR Gun
you can find clogged rad tubes. or hot spots in cooling loop
you can check each exhaust tubes to see if all are runnign same temp looking for weak or dead cylinders (with out getting shocked by pulling the spark plugs)
smoke machine. (home made is cool)
I never need it in DYI mode cuz i can test for leaks other ways.
i found a bad IAC buy the process of elimiation.
buy testing all vac, parts and finding them good, this proved bad IAC, and it was.
(motor had new gaskets, 100% )
ok that is my comments about all post here that are missing basics.
basics are never to be avoided.
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