the car has extreme wiring hacks, who knows how bad , no?
Is there any more tests I can do to make sure it is good?? dissy.
the distrib. works just like all pre EFI cars did .
Vacuum advance, mech. (ever seen an old distrib test machine in a auto shop? it spins the distrib and you test the advance,pure mechanics there.
centrifugal advance mech, actions on rpm
and the VR and ignitor pair, if the timing light does now flash steady , (you said it has issues at 3000 RPM) and if not consistent flashing , the VR/ignitor pair are bad. (and as always, bad power and ground to the distributor) It must advance per the book on the car.
the RPM setting device on this car, is the TV throttle stop screw, there is no other screws to play with here. see on the Idle page i sent.
here (the actual manual pages are here for only your car) with photos and diagrams
http://www.fixkick.com/IDLE-AIR/89-90-idle-air.html
just 1. if you CCW that and if the rpm can not be set (all electrics off) hot engine, , is it hot? then there are vacuum leaks. or the ISC it self leaks, but that too is a vacuum leak.
all 8v engines race fast with any kind of vacuum leak that the ISC can not control.
I have turned idle speed screw CCW to set 750-850 rpm at idle hot. Is this the same screw as throttle stop screw? Or am I lost?
1989 Rubicon caps are no good. now. there life has ended, 20 years is par, but these failed way before now,, the corner big cap is the worst offender.
the fuel pressure tests is covered on the pump page, type pump in the search box? yet? fixkick.com
the pressure is checked with a tool called a fuel pressure gauge. at the filter test port, there is no engine side test port. on this car. none.
The FPR is a regulator on the side of the TB throttle body, it is for altitude, it sets fuel pressure with altitude. only,'
if the vac hose is detached, engine off, it must not leak fuel there, if yes it is bad. (the pump page.)
http://www.fixkick.com/INJECTORS/pump.html
off this page, and 89 it shows.
1989/90 = 34.1 to 39.8 PSI. Key on cranking and idling. (keyon does not build pressure 89/90 years only))
GM shows this spec. as: 34-41 PSI. (do not exceed 41 )
This ECU can not work correctly at all of pressure is too high. or too low. it must be inspec. (in specification) this means that if too high , (say) the ECU will over inject fuel.
This ECU is blind here, it can not know if pressure is wrong, (like all modern cars can) so does the wrong thing, when wrong.
at lower altitudes the PSI will be closer to 41PSI.
the ISC is Idle speed controls
hot engine only,. 180f is hot, is yours hot? using 160F thermostat wrecks all this fine tuning the ECU can do. use the correct 180,192,195F thermostat.
the ISC when hot, engine, tries its best to hold 800rpm l this is a computer ecu regulated action, the IAC is just a fast acting air valve solenoid.
The ISC opens more as you add electrical loads.
the ISC opens wider with headlamps turned on, there is DIODE block under the dash that turn up idle RPM called fast idle mode, for 45 reasons
1-Head lamps on. +) eash of the below tells the ECU to go to 1000 RPM mode.
2- dash heater blower turned on.
3 rear window Electric heater grid defrost on.
4 P/S overload (ever hear your Power steering squeal when over cranked. bingo overload. (all cars)
5 A/C on. some cars have A/C as an option. (all cars)
this is why they say all electrics off to set idle speeds.
The ISC will fail for many reasons .... like the below.
1: the ISC is bad. or even has bad gaskets or leaks inside.
2: the ISC is not calibrated correctly per the links above. i bet you cant due to the below.
3: vacuum leaks rendering it useless. the ISC closes 100% with vacuum leaks and once at 100% closed, it can not regulate RPM with it stuck closed, fix the leaks first.
the VR gap (variable reluctor coil) is just that a spec, gap. if too wide or narrow might cause it to misfire.
you can see it misfire with the timing light.
I can not hear the engine run so cant hear misfire, if you have misfiring this is s first thing first issue.
do you? if yes spark actually is bad, then the distrib and its main SPARK coil are bad.
you did a tuneup on it I see but skipped the 29 year old spark wires, why skip that, those are in the HOPELESS pile there, (we run mag wires here, the best for weak spark like that)
The ISC will not make the car run better,
all it does is keep rpm at 800 , that is it, (well mostly)
this EFI system runs mostly off the MAP, (and 02 sensors) are you running a 29 year OLD 02? (that too is hopeless if that old, totally not possible it good if that old.
1: tuneup done., partially, no spark wires replaced.,
2: idle is not regulating I bet. but this in and of itself is no crysis on any 8v sidekick or tracker , even from JAPAN not CAMI, yours is the first ones made ever. (like prototype? lol)
3: unknown fuel pressure.
4: no 02 replaces (im guessing ok? blind )
5: map hoses and ports clean to it yet, this is a key service here, never to be skipped, the MAP is the heart and soul of of this speed density fuel injection system, as is #3
6: no vacuum hose leaks, minor leaks will not cause engine to misfire, ever, infact runs faster and makes more power is what leaks do on on the unique 8valve engine EFI.
btw 800 rpm is same as 850 , its in spec. 750 to 850 is spec, ok? what matters is regulation at that rpm. it must regulate.
one way to test this is to turn on head lamps, the DIODE pack sees you do that then the ECU raises rpm to 920 to 1000 rpm, (a 200 rpm) if this works the ISC is NOT DEAD.
ever do spark tip checks.
if the engine misfires,
stop engine,
take out a plug or 2 and read the tips. the tips must look clean, if not bad.
this was done from year 1910 on all cars to now.
EFI burns all the fuel and is a no lead clean fuel so the tips of spark plugs burn clean today, (means 1989 to now in your case)
add to the photo below, green tips , antifreeze leaks, (or as the color of your coolant may be)
![[Image: verygoodsparkchart1a.jpg]](http://www.fixkick.com/IGN_timing/verygoodsparkchart1a.jpg)
my wild guess is.
engine misfires, heard and felt and even seen engine to shake.
Caused by, bad spark.
or cause by gross rich fuel mixtures, as seen in carbon fouling above.
Is there any more tests I can do to make sure it is good?? dissy.
the distrib. works just like all pre EFI cars did .
Vacuum advance, mech. (ever seen an old distrib test machine in a auto shop? it spins the distrib and you test the advance,pure mechanics there.
centrifugal advance mech, actions on rpm
and the VR and ignitor pair, if the timing light does now flash steady , (you said it has issues at 3000 RPM) and if not consistent flashing , the VR/ignitor pair are bad. (and as always, bad power and ground to the distributor) It must advance per the book on the car.
the RPM setting device on this car, is the TV throttle stop screw, there is no other screws to play with here. see on the Idle page i sent.
here (the actual manual pages are here for only your car) with photos and diagrams
http://www.fixkick.com/IDLE-AIR/89-90-idle-air.html
just 1. if you CCW that and if the rpm can not be set (all electrics off) hot engine, , is it hot? then there are vacuum leaks. or the ISC it self leaks, but that too is a vacuum leak.
all 8v engines race fast with any kind of vacuum leak that the ISC can not control.
I have turned idle speed screw CCW to set 750-850 rpm at idle hot. Is this the same screw as throttle stop screw? Or am I lost?
1989 Rubicon caps are no good. now. there life has ended, 20 years is par, but these failed way before now,, the corner big cap is the worst offender.
the fuel pressure tests is covered on the pump page, type pump in the search box? yet? fixkick.com
the pressure is checked with a tool called a fuel pressure gauge. at the filter test port, there is no engine side test port. on this car. none.
The FPR is a regulator on the side of the TB throttle body, it is for altitude, it sets fuel pressure with altitude. only,'
if the vac hose is detached, engine off, it must not leak fuel there, if yes it is bad. (the pump page.)
http://www.fixkick.com/INJECTORS/pump.html
off this page, and 89 it shows.
1989/90 = 34.1 to 39.8 PSI. Key on cranking and idling. (keyon does not build pressure 89/90 years only))
GM shows this spec. as: 34-41 PSI. (do not exceed 41 )
This ECU can not work correctly at all of pressure is too high. or too low. it must be inspec. (in specification) this means that if too high , (say) the ECU will over inject fuel.
This ECU is blind here, it can not know if pressure is wrong, (like all modern cars can) so does the wrong thing, when wrong.
at lower altitudes the PSI will be closer to 41PSI.
the ISC is Idle speed controls
hot engine only,. 180f is hot, is yours hot? using 160F thermostat wrecks all this fine tuning the ECU can do. use the correct 180,192,195F thermostat.
the ISC when hot, engine, tries its best to hold 800rpm l this is a computer ecu regulated action, the IAC is just a fast acting air valve solenoid.
The ISC opens more as you add electrical loads.
the ISC opens wider with headlamps turned on, there is DIODE block under the dash that turn up idle RPM called fast idle mode, for 45 reasons
1-Head lamps on. +) eash of the below tells the ECU to go to 1000 RPM mode.
2- dash heater blower turned on.
3 rear window Electric heater grid defrost on.
4 P/S overload (ever hear your Power steering squeal when over cranked. bingo overload. (all cars)
5 A/C on. some cars have A/C as an option. (all cars)
this is why they say all electrics off to set idle speeds.
The ISC will fail for many reasons .... like the below.
1: the ISC is bad. or even has bad gaskets or leaks inside.
2: the ISC is not calibrated correctly per the links above. i bet you cant due to the below.
3: vacuum leaks rendering it useless. the ISC closes 100% with vacuum leaks and once at 100% closed, it can not regulate RPM with it stuck closed, fix the leaks first.
the VR gap (variable reluctor coil) is just that a spec, gap. if too wide or narrow might cause it to misfire.
you can see it misfire with the timing light.
I can not hear the engine run so cant hear misfire, if you have misfiring this is s first thing first issue.
do you? if yes spark actually is bad, then the distrib and its main SPARK coil are bad.
you did a tuneup on it I see but skipped the 29 year old spark wires, why skip that, those are in the HOPELESS pile there, (we run mag wires here, the best for weak spark like that)
The ISC will not make the car run better,
all it does is keep rpm at 800 , that is it, (well mostly)
this EFI system runs mostly off the MAP, (and 02 sensors) are you running a 29 year OLD 02? (that too is hopeless if that old, totally not possible it good if that old.
1: tuneup done., partially, no spark wires replaced.,
2: idle is not regulating I bet. but this in and of itself is no crysis on any 8v sidekick or tracker , even from JAPAN not CAMI, yours is the first ones made ever. (like prototype? lol)
3: unknown fuel pressure.
4: no 02 replaces (im guessing ok? blind )
5: map hoses and ports clean to it yet, this is a key service here, never to be skipped, the MAP is the heart and soul of of this speed density fuel injection system, as is #3
6: no vacuum hose leaks, minor leaks will not cause engine to misfire, ever, infact runs faster and makes more power is what leaks do on on the unique 8valve engine EFI.
btw 800 rpm is same as 850 , its in spec. 750 to 850 is spec, ok? what matters is regulation at that rpm. it must regulate.
one way to test this is to turn on head lamps, the DIODE pack sees you do that then the ECU raises rpm to 920 to 1000 rpm, (a 200 rpm) if this works the ISC is NOT DEAD.
ever do spark tip checks.
if the engine misfires,
stop engine,
take out a plug or 2 and read the tips. the tips must look clean, if not bad.
this was done from year 1910 on all cars to now.
EFI burns all the fuel and is a no lead clean fuel so the tips of spark plugs burn clean today, (means 1989 to now in your case)
add to the photo below, green tips , antifreeze leaks, (or as the color of your coolant may be)
my wild guess is.
engine misfires, heard and felt and even seen engine to shake.
Caused by, bad spark.
or cause by gross rich fuel mixtures, as seen in carbon fouling above.
http://www.fixkick.com