all rough idles, are misfire.
when the engine is too rich (example) that causes too rich misfiring, and is like 99% of all misfires on G16s this.
if you watch the engine it shacks and you hear the uneven beat ,that is misfiring,,, on all engines.
that black is rich misfire, normal is (cream, white, super light gray, but never see carbon of any kind there.) or is MISFIing
ever run a chain saw?, that uneven idle is misfire.
this ecu is brick stupid, it sees only, things that fell off, or shorted. (code 12 means , nothing fell off EFI inputs) that is it .... yes, dumb is the word on this ECU
and is same ECU used on all sidekicks,/tracker/sunrunners) same for same transmission. 56Bxx it is...
not like the 1400 errors my new jeep can throw.
code 12, does that mean you can drive car and it flashes 12s driving, (this is important because not all problems are static, problems can be intermittent or LOAD and vibration effected)
what do we know, ?
"thing to improve the performance" so what does that mean?
you never ran a 80HP G16a before?, or you have and this new engine is weak. ?
you say its rough, that means when cold /hot or both,?
if its rough hot, that is called misfire, for sure.
rough does mean misfire. and if cat is old and dead, you even smell it, if cat is new the cat over heats on all cars made, (gas)
if engine is weak, (say so) and if its rough then it is misfiring, we can work that, my page has very long misfiring section.
misfires has vast causes, over 50,,but if reduce that by saying engine is GOOD. (as it seems) and vacuum gage shows no bouncing then
the new (used )engine is good.
so next is spark then EFI.
lets do a list. first,
engine is ok, 150psi. cam belt seems not slipped,. it will do 170psi warm or hot, engine.
so if spark wires and plugs good, and gap at 0.028" never ever at .045" as sold in all new boxes.....
then we check spark timing,
is hot rpm always at 800 rpm??????????
with that working
we insert the timing freeze jumper and check spark timing, (normally it bounces like mad, all EFI does that) so needs the FREEZE jumper set.
ok lets say you did that and its at spec.
that leaves EFI issues.
what is next, my jeep books are 10x better on this....
my jeep books show 12 things even modern cars (EFI BRAINS) are blind to,
#1 on that list (and true here)
is fuel pressure, the ECU can not inject fuel properly unless it's correct.
but costs $20 to buy the tool.
if say the FPR fails as all do about now. the reg can stick closed, and pressure shoots from like 34psi to 55psi, and guess what, ECU IS FLUMMOXED.
on a hot engine so can a bad 02 sensor. cause rich misfire
so can a leaking injector
so can a crack near the 02 sensor, exhaust cracks are nOT allowed, there. ever. air has 20 % oxygen, and 20% slams the 02 lean, and EFI goes max rich.
ECT does not read 300-OHMS hot, get engine hot, key off, ECT unpugged, it measure 300 ohms if not, near there (ball park) this is a BINGO HARD FAIL.
the ECU has no idea at all what reality is., it trusts the sensors, so a BIASed sensor is UNSEEN.
Unseen means it has no way at all to know, IT'S WRONG.(it can only detect DEAD sensors)
IAT reads correctly? . using my IAT,/ECT page (chart, it uses the same ohms rules)
if all is ok, with ECU inputs, then the ECU is bad.
the ECU injects on inputs,.
and if those are correct and injection rates are wrong, (excessive)then the ECU is bad. (fuel pressure above at spec and 1st)
one way for this to happen is a short, injector driver transistor. (the other wire fires, but timed wrong)
the other way is the ECU has bad CAP.'S.
with bad caps the ECU keeps rebooting over and over, like a drummer boy beating his drum, (all caps 89 to 95 all fail 1 time. are yours original)?
called Rubicon death?
this cause the ECU to go nuts. and injects wrongly, and it's too stupid to warn you. (like today's cars will do)
your ECU is not in limphome mode 12s, that too is rich misfire if not 12s.
your eCU is not in backup mode, it flashes 12. so , not this..
both modes will caused misfire and both are rich and gross retarded sparking and loss of power. (limp is the key word here).
recap.
engine tests good
spark good. timed to spec, gapped to spec.
no exhaust leak near 02. (cracks or gaskets bad there, not allowed )
fuel pressure at spec. and the injector leak down test passes ! and the FPR tests pass. (pressure on 8v holds steady.) unlike the G16b , why more complex that.
ECU inputs tested. (all) includes map tests. see my MAP page, there is a page for every sensor.
ecu bad.? cap leaking, did you look first, this is day 1 check after loose crank bolt, pulley bolt. not at 94ft/lbs.
that is it! for TBI tests, its only got 1 injector so is more easy, and no funky MAF.
forgot to say the #3 check
engine reaches and holds 180F or more water temp.
it must. holding matters, this year engine, you never told me the year of used engine,
the 1994 car has 2 intake manifold. G16a
you can not use the wrong thermostat seals or the water temps will HUNT like made, endlessly.
and ECU goes nuts with it.
type frigid in my search box
http://www.fixkick.com/Cooling-engine/Fr...r-cab.html
what thermostat housing in hand, if lip is 4mm on manifold pit edge this is NEW style.
and must have a rubber ring seal, , MUST.
or it will run rich and misfire and will lose power. and performance,
when the engine is too rich (example) that causes too rich misfiring, and is like 99% of all misfires on G16s this.
if you watch the engine it shacks and you hear the uneven beat ,that is misfiring,,, on all engines.
that black is rich misfire, normal is (cream, white, super light gray, but never see carbon of any kind there.) or is MISFIing
ever run a chain saw?, that uneven idle is misfire.
this ecu is brick stupid, it sees only, things that fell off, or shorted. (code 12 means , nothing fell off EFI inputs) that is it .... yes, dumb is the word on this ECU
and is same ECU used on all sidekicks,/tracker/sunrunners) same for same transmission. 56Bxx it is...
not like the 1400 errors my new jeep can throw.
code 12, does that mean you can drive car and it flashes 12s driving, (this is important because not all problems are static, problems can be intermittent or LOAD and vibration effected)
what do we know, ?
"thing to improve the performance" so what does that mean?
you never ran a 80HP G16a before?, or you have and this new engine is weak. ?
you say its rough, that means when cold /hot or both,?
if its rough hot, that is called misfire, for sure.
rough does mean misfire. and if cat is old and dead, you even smell it, if cat is new the cat over heats on all cars made, (gas)
if engine is weak, (say so) and if its rough then it is misfiring, we can work that, my page has very long misfiring section.
misfires has vast causes, over 50,,but if reduce that by saying engine is GOOD. (as it seems) and vacuum gage shows no bouncing then
the new (used )engine is good.
so next is spark then EFI.
lets do a list. first,
engine is ok, 150psi. cam belt seems not slipped,. it will do 170psi warm or hot, engine.
so if spark wires and plugs good, and gap at 0.028" never ever at .045" as sold in all new boxes.....
then we check spark timing,
is hot rpm always at 800 rpm??????????
with that working
we insert the timing freeze jumper and check spark timing, (normally it bounces like mad, all EFI does that) so needs the FREEZE jumper set.
ok lets say you did that and its at spec.
that leaves EFI issues.
what is next, my jeep books are 10x better on this....
my jeep books show 12 things even modern cars (EFI BRAINS) are blind to,
#1 on that list (and true here)
is fuel pressure, the ECU can not inject fuel properly unless it's correct.
but costs $20 to buy the tool.
if say the FPR fails as all do about now. the reg can stick closed, and pressure shoots from like 34psi to 55psi, and guess what, ECU IS FLUMMOXED.
on a hot engine so can a bad 02 sensor. cause rich misfire
so can a leaking injector
so can a crack near the 02 sensor, exhaust cracks are nOT allowed, there. ever. air has 20 % oxygen, and 20% slams the 02 lean, and EFI goes max rich.
ECT does not read 300-OHMS hot, get engine hot, key off, ECT unpugged, it measure 300 ohms if not, near there (ball park) this is a BINGO HARD FAIL.
the ECU has no idea at all what reality is., it trusts the sensors, so a BIASed sensor is UNSEEN.
Unseen means it has no way at all to know, IT'S WRONG.(it can only detect DEAD sensors)
IAT reads correctly? . using my IAT,/ECT page (chart, it uses the same ohms rules)
if all is ok, with ECU inputs, then the ECU is bad.
the ECU injects on inputs,.
and if those are correct and injection rates are wrong, (excessive)then the ECU is bad. (fuel pressure above at spec and 1st)
one way for this to happen is a short, injector driver transistor. (the other wire fires, but timed wrong)
the other way is the ECU has bad CAP.'S.
with bad caps the ECU keeps rebooting over and over, like a drummer boy beating his drum, (all caps 89 to 95 all fail 1 time. are yours original)?
called Rubicon death?
this cause the ECU to go nuts. and injects wrongly, and it's too stupid to warn you. (like today's cars will do)
your ECU is not in limphome mode 12s, that too is rich misfire if not 12s.
your eCU is not in backup mode, it flashes 12. so , not this..
both modes will caused misfire and both are rich and gross retarded sparking and loss of power. (limp is the key word here).
recap.
engine tests good
spark good. timed to spec, gapped to spec.
no exhaust leak near 02. (cracks or gaskets bad there, not allowed )
fuel pressure at spec. and the injector leak down test passes ! and the FPR tests pass. (pressure on 8v holds steady.) unlike the G16b , why more complex that.
ECU inputs tested. (all) includes map tests. see my MAP page, there is a page for every sensor.
ecu bad.? cap leaking, did you look first, this is day 1 check after loose crank bolt, pulley bolt. not at 94ft/lbs.
that is it! for TBI tests, its only got 1 injector so is more easy, and no funky MAF.
forgot to say the #3 check
engine reaches and holds 180F or more water temp.
it must. holding matters, this year engine, you never told me the year of used engine,
the 1994 car has 2 intake manifold. G16a
you can not use the wrong thermostat seals or the water temps will HUNT like made, endlessly.
and ECU goes nuts with it.
type frigid in my search box
http://www.fixkick.com/Cooling-engine/Fr...r-cab.html
what thermostat housing in hand, if lip is 4mm on manifold pit edge this is NEW style.
and must have a rubber ring seal, , MUST.
or it will run rich and misfire and will lose power. and performance,
http://www.fixkick.com