95 tracker miss after warm up

[1995 toad]

I have a 95 tracker that I think has a lean miss after warm up new plugs wires cap rotor air filter fuel filter 150 ish all cylinders belt is good bolt is tight fuel is 35 start 31 run no cel tps tests all good does same miss with o2 disconnected idles great and runs good until it warms up then it has an intermittent sporadic miss. when it misses the injectors make a clattering sound instead of the crisp click at idle when listened to with a stethoscope.  cant figure this one out will be pulling the ecu to check caps.. I need some advice. thanks in advance

[fixkick]

I have a 95 tracker that I think has a lean miss after warm up new plugs wires cap rotor air filter fuel filter 150 ish all cylinders belt is good bolt is tight fuel is 35 start 31 run no cel tps tests all good does same miss with o2 disconnected idles great and runs good until it warms up then it has an intermittent sporadic miss. when it misses the injectors make a clattering sound instead of the crisp click at idle when listened to with a stethoscope.  cant figure this one out will be pulling the ecu to check caps.. I need some advice. thanks in advance

95 16valve +  misfiring.

is idle at 800rpm hot? and car have full power on hills?

if spark is good and timing for spark at spec, (others messing with cam belt can get this set all wrong (cam and distrib)

first prove spark is ok

and spark tips are not , black,green,oil wet, or fuel wet dripping, or other odd things there)

the gap is 0.028" not ever out of  box  ignored and set to 0.045" as NGK sets them (their wild guess is wrong) this car is not high energy spark thus  narrow gap.

spark not bad above then it must be fueling.

next is engine, good.

150psi is low is that on all 4 jugs(cylinders)? my guess done on dead cold engine,  compression test here.

warm or hot engine sea level and throttle must be blocked 1/2 to full WOT  open and let the needle peak do not count engine turns ever. peak it.
of low and 150 is, warm to hot,  try the wet test, if it shoots up to 190  or so, the rings are very worn.  always log all 4 cylinders, to see them all equal.
The 16v is [b]195 PSI. Seen in  FSM chapter 6-6 (not 6A1)  Facts.  <<< true spec, not my car.[/b]
my data:

My 1996 Geo Tracker 1.6Liter 16valve. , pulls 183-185 PSI on all 4 cylinders. (warm )

My 97' pulls 185 PSI min. dead cold. (a new head) later  and  hot it does 195 PSI.  Old 100k mile engine, now with  new oil rings, new crank and new head.



Valve lash not at spec, if set too tight a hot engine can misfire or burn those valves up.

vacuum gauge test shows 19" vacuum hot 800 RPM idle but never BOUNCING VAC, ever.



fuel pressure at  spec and , 6 PSI change from keyon to hot idle? must be, or FPR is bad.  36PSi keyon then 30psi at idle is common , 6psi must be seen difference.
Lots of FPR this old fail, or even leak fuel out the VAC nipple. oops bad FPR.

injector leak down test passes, then balance test can be done.

and the more difficult injector, balance test pass? all four do the PSI drop down test equally timed.?



----------------------------------------next is EFI--------------------------------------------------------

those 4  injectors are PWM modulated, fast, to keep them cool so the 3.2MS pulse at idle , there  chopper driving that pulse, ive never heard that sound.

Ive scoped  it for  sure, and chopped. (the chopper is injector cooling and but the injector never  reacts to the chop only the slow 3.2mS hot idle pulse.

those cooling pulses are 33kHz,  only dogs can hear that, not me for sure,see  that on my scope but hear no, the 3.2mS sure as a click only.

Chattering to me smacks of  ECU crashing, (bad caps do that) bad caps can also make VSV valves on car go nuts and chatter,  and more,  



95 has no oBD2 scan tools that work 96+

so is much harder to diagnose.  



fuel is 35 start 31 ? what are these number, and how obtained?



O2 pulled only causes, better running if ,hot engine, the cracked exhaust at #4 tube (classic) makes good O2 read 0v and if you unplug o2 it goes to 0.45v

and now engine runs better hot,  or o2 is fully dead, pulling it can make fuel mix go better.

if the injectors actually really chatter, at the actually pintle,, true,  that smacks of bad caps in ECU  , but  PWM cooling pulse could be heard. IDK.



hit list on EFI  is all sensors , input wrong;

1. bad caps is not a sensor but top of all old ECU  never upgraded CAPS list.  (the big corner cap loves to fail)
   
2. ECT does not read 300 ohms on fully hot engine (pull plug ohm meter  to 2 pins read) DMM set to resistor range'
   
3. IAT is not it. but can be tested same as ECT using chart for that,   but why bother? the 92 has no IAT, so...
   
4. O2 tells lies, dead, or erratic or old 100,000 miles rated, and or the #4 exhaust header is cracked. sucking in air making O2 read dead wrong.
   
5. MAF bad. (or china $17 clone here, a good maf marks are 58BOO ,  suzuki marked, if not the maf is clone or refurb. clean the maf  from 8 " distance <cleaner.
   
6. TPS bad.  if the ohms readings are smooth ,it is good, if TP pin varies from say 1v and 3.5v smoothly key on , no start, and hand moved throttle it is good.
   
7. bad ECU but #1 gets most cured.
   

Good luck to you and hope all this pans out. good.

cheers and happy holidays

[1995 toad]

150 was cold on all cylinders
ect reads 300
tps all smooth
o2 seems to make no difference plugged in or not no cracks in exhaust
need to pull ecu to check
fuel pressure was taken at the cap at the end of the rail.
cleaned maf
injectors only make the chattering sound when missing
plugs where fully light gray with no heat lines on the strap.
vacuum was stable at 19 at fpr port

[fixkick]

150 was cold on all cylinders
ect reads 300
tps all smooth
o2 seems to make no difference plugged in or not no cracks in exhaust
need to pull ecu to check
fuel pressure was taken at the cap at the end of the rail.
cleaned maf
injectors only make the chattering sound when missing
plugs where fully light gray with no heat lines on the strap.
vacuum was stable at 19 at fpr port

on these years it is very hard to see if the ECU can hold closed loop 02 status.
but  your 1 symptom  above  seem to hint that is dead. (no difference)
try new 02 yet?
in shop we scope the 02 fan see it fail, stuck and not swinging, telling me, closed loop is dead.
we create vacuum leak to see if the O2 wakes up, or force rich by playing with vacuum port on FPR.
that trick on FPR is simple pull the vacuum line and put golf TEE in the sucking hole. hose.
now FPR is 6psi fuel pressure higher and it goes rich, and 02 may wake up. and swing,
if 02 is dead under all tests, the O2 is bad, or cracks near by are there . even exhaust header collector end gasket bad or just loose.
seem this is lean misfire, to me,, most these cars fail rich, super rich and spark tips black.
is the MAF marked 58B00 (and mitsubish logo, like it was new)  the last poster here had this china crap MAF< that had way too high readings, (gm/s)
and no o2 in the world could correct that nasty error.
I see  like 25 china brands sold at amazon, for $20 and all are junk and that means get landed on lots of cars just because  $20 is 1/6 normal price.

I'd see that in person in a minute.  all things wrong just by site,  missing and wrong parts and hacks.
even 02 sensors hacks.
what is your MAF output pin , voltage reading at hot 800rpm idle>>?  spec is 1.7–2.0 volts. at 800 RPM

keyon is 1.0 to 1.6, and idle near 2v.
gun throttle see 3v, and much more driving up a hill making full 95hp on engine.   (a good maf ) if weak MAF 95hp never can happen)  that is why I asked about hills.

[1995 toad]

haven't tested maf used to run great going up hills and wot... would only miss steady state drive ..
ecu out now.. all stock caps.. ordered kit ...don't look bad but will replace
when i pulled in the shop ran great through full rpm range cold.
its killing me...lol

[fixkick]

haven't tested maf used to run great going up hills and wot... would only miss steady state drive ..
ecu out now.. all stock caps.. ordered kit ...don't look bad but will replace
when i pulled in the shop ran great through full rpm range cold.
its killing me...lol

i forgot blush
new spark coiL?  all else is new but not this. (coils do fail)
if you pull the vacuum hose off FPR there are 2 tests to try easy,
one is with fpr hose pulled and golf teed, so it can now suck air,
this act raises fuel pressure  6psi and if running gets worse,  then we know it was rich and  is more rich now,  we know it is rich misfiring, but if gets better running then we know the fuel mix was way too lean . a very simple and many times revealing test.

put that hose back now . to normal.
test 2:
then pull the front hose on that  front plenum box of intake manifold. there are 2 hoses short. one is fpr and  left of it is EVAP,so
see 2 short hoses.
pull the left hose X front,  this is EVAP hose. at hot idle this will cause lean out, and if runs better implies, engine was too rich.
if it gets worse you have vacuum leak or have bad maf. (or just needs to be cleaned)
the maf is a hot wire MAF  and can COKE up as you drive in heavy traffic,  and when that happens it reads low and EFI fuel mix goes way lean
the ECU will no know this until voltage out is below near dead 0.6vdc. we clean them every 50k miles for sure,  but keep the spray back about 8"inches
to not damage that hot wire,  58B00 MAF is yours marked correctly as that?

ARE  all giant hoses to the MAF to TB all good, no bad gaskets end to end.
My 96 the main huge intake tube up top that PO lost the bolts to the mount there and it beat itself to death, (mount #19 here)
#17 to 21 must not leak.
the mount aluminum cracked off and that huge pipe sucked are like mad. this made engine go lean and no power. (called unmetered MAF air) The whole induction path maf to TB must be checked any time lean is suspected. on any mAF cars, (on 8v it races fast with full power these leaks) but the 16v never acts like that it goes super lean and lost of power, ever idle wants to stall if bad enough.

no air leaks at ISC (marked test) hose nor PCV . (btw good luck to you !!!)

[1995 toad]

haven't tested maf used to run great going up hills and wot... would only miss steady state drive ..
ecu out now.. all stock caps.. ordered kit ...don't look bad but will replace
when i pulled in the shop ran great through full rpm range cold.
its killing me...lol

i forgot blush
new spark coiL?  all else is new but not this. (coils do fail)
if you pull the vacuum hose off FPR there are 2 tests to try easy,
one is with fpr hose pulled and golf teed, so it can now suck air,
this act raises fuel pressure  6psi and if running gets worse,  then we know it was rich and  is more rich now,  we know it is rich misfiring, but if gets better running then we know the fuel mix was way too lean . a very simple and many times revealing test.

put that hose back now . to normal.
test 2:
then pull the front hose on that  front plenum box of intake manifold. there are 2 hoses short. one is fpr and  left of it is EVAP,so
see 2 short hoses.
pull the left hose X front,  this is EVAP hose. at hot idle this will cause lean out, and if runs better implies, engine was too rich.
if it gets worse you have vacuum leak or have bad maf. (or just needs to be cleaned)
the maf is a hot wire MAF  and can COKE up as you drive in heavy traffic,  and when that happens it reads low and EFI fuel mix goes way lean
the ECU will no know this until voltage out is below near dead 0.6vdc. we clean them every 50k miles for sure,  but keep the spray back about 8"inches
to not damage that hot wire,  58B00 MAF is yours marked correctly as that?

ARE  all giant hoses to the MAF to TB all good, no bad gaskets end to end.
My 96 the main huge intake tube up top that PO lost the bolts to the mount there and it beat itself to death, (mount #19 here)
#17 to 21 must not leak.
the mount aluminum cracked off and that huge pipe sucked are like mad. this made engine go lean and no power. (called unmetered MAF air) The whole induction path maf to TB must be checked any time lean is suspected. on any mAF cars, (on 8v it races fast with full power these leaks) but the 16v never acts like that it goes super lean and lost of power, ever idle wants to stall if bad enough.

no air leaks at ISC (marked test) hose nor PCV . (btw good luck to you !!!)

Resistors finally got here... soldered in .. fired up great runs good until warm up then same miss as rpm is added. idles great 
pulled fpr hose plugged vacuum leak ...fuel pressure 41 runs the same.
evap hose pulled... misses the same
cleaned maf  runs the same ... what brand of cleaner you prefer?
will check again for vacuum leaks

[1995 toad]

haven't tested maf used to run great going up hills and wot... would only miss steady state drive ..
ecu out now.. all stock caps.. ordered kit ...don't look bad but will replace
when i pulled in the shop ran great through full rpm range cold.
its killing me...lol

i forgot blush
new spark coiL?  all else is new but not this. (coils do fail)
if you pull the vacuum hose off FPR there are 2 tests to try easy,
one is with fpr hose pulled and golf teed, so it can now suck air,
this act raises fuel pressure  6psi and if running gets worse,  then we know it was rich and  is more rich now,  we know it is rich misfiring, but if gets better running then we know the fuel mix was way too lean . a very simple and many times revealing test.

put that hose back now . to normal.
test 2:
then pull the front hose on that  front plenum box of intake manifold. there are 2 hoses short. one is fpr and  left of it is EVAP,so
see 2 short hoses.
pull the left hose X front,  this is EVAP hose. at hot idle this will cause lean out, and if runs better implies, engine was too rich.
if it gets worse you have vacuum leak or have bad maf. (or just needs to be cleaned)
the maf is a hot wire MAF  and can COKE up as you drive in heavy traffic,  and when that happens it reads low and EFI fuel mix goes way lean
the ECU will no know this until voltage out is below near dead 0.6vdc. we clean them every 50k miles for sure,  but keep the spray back about 8"inches
to not damage that hot wire,  58B00 MAF is yours marked correctly as that?

ARE  all giant hoses to the MAF to TB all good, no bad gaskets end to end.
My 96 the main huge intake tube up top that PO lost the bolts to the mount there and it beat itself to death, (mount #19 here)
#17 to 21 must not leak.
the mount aluminum cracked off and that huge pipe sucked are like mad. this made engine go lean and no power. (called unmetered MAF air) The whole induction path maf to TB must be checked any time lean is suspected. on any mAF cars, (on 8v it races fast with full power these leaks) but the 16v never acts like that it goes super lean and lost of power, ever idle wants to stall if bad enough.

no air leaks at ISC (marked test) hose nor PCV . (btw good luck to you !!!)

Resistors finally got here... soldered in .. fired up great runs good until warm up then same miss as rpm is added. idles great 
pulled fpr hose plugged vacuum leak ...fuel pressure 41 runs the same.
evap hose pulled... misses the same
cleaned maf  runs the same ... what brand of cleaner you prefer?
will check again for vacuum leaks

no vacuum leaks either...

[1995 toad]

new resistors in ecm... same inconsistent missing above idle
checked intake tract and hoses for vacuum leaks with start fluid... same inconsistent miss above idle
checked maf as per maf checking...good... same inconsistent miss above idle
no cel

[fixkick]

new resistors in ecm... same inconsistent missing above idle
checked intake tract and hoses  for vacuum leaks with start fluid... same inconsistent miss above idle
checked maf as per maf checking...good... same inconsistent  miss above idle
no cel

try newer set of spark plug wires
seen many folks tune up and the new set is no good. (my guess sold to others then yanked off other engine , and resold as new.)
or bad spark coil

must be spark is bad some how and check all grounds to the distributor or to the fire wall ignitor and coil