thrown parts never fixes cars. 50 causes, can be 49 time guesing wrong or worse added a new defective part to the mix.
yes finish the tune up, why did you do it last>? odd no?
vacuum leaks cause, high idle on all jeeps!!
and then the ECU sees bad idle and tries over and over to reach
700rpm (spec) and cant so hunts it (that hunting today is deemed ******* , ask toyota why , fines)
all vacuum leaks do that , if it sucks AIR , illegally it will do that.
illegalll means air not from the ISC stepper drive device.
bad hoses, bad gaskets what ever.
does engine reach and hold 180f coolant temperatures???
this is first. it must, does it?
ill not guess, I propose doing a thing called TESTING.
lots of thoughts, really .... here are mine, plus RENIX facts.
I owed 2 , 1988s, with dang REnix french EFI? a horrid system.
TBI is yours TBI not MPI? (count the injectors there) mpi is 4.
no sold scan tools work on it
and no CEL lamp. on RENIX.
nor does the key on 3 times trick. work before 91, dang!
1991 it changed to far better and the 3 key trick works then...
black smoke is: (rich)
high fuel pressure. (id be all over this)
injector leaks, (do a leak down test )
ECT bad, e (old name CTS)
on a hot engine, it reads (ohmmeter tests)
25,000 ohms is wrong, for 0degr. F.
317 ohms is about par for 180f normal temp , is yours 300 hot unplugged??????. a simple 5 min test.
if not the thermostat is bad or CTS bad. (IR gun it to learn this)
i see that rough idle , its MISFIRING
and its really flooding .
and black smoke is always results of that, and most CATcons this old are now dead, (cat converter on all mine broke-up to bits and gone inside, and stinks any time it's rich or misfiring) par for 90s./:
the 1990 wangler books are rare, but can be found on ebay
buy one is my best advice,
its and old jeep
and its best to check compression on all old cars.
did you? x5 warm or hot, and WOT tested, (throttle open)
the 2.5L most 1990(not 91)
have TBI and ****** RENIX EFI (French junk)
only jeep dealer scan tools work here, not you.
the injector must not leak. just 1 injector here,
(key off running does it dribble now? must not) looking with eyes./
(the SM is in my hands) service manual..
2.5L (NOT 4.2L)
conducted a tune-up last
cap,rotor, wires, sparks and filters is a full tuneup on any neglected 90s jeep.
good engine first
then fueling last.
order matters, on old cars,
yes all injectors tick but yours has only 1.
and takes a stethoscope to hear. (or my mag sensor tool)
this AMC spark system uses and ICM 2.5L only
and 50 tooth CMP sensors in the Distributor. (CPS you called it?)
my guess you replaced the TDC sensor
TDC sensor (mounted at the rear of the engine on the flywheel housing) CKP its called today. (yes names all changed long ago)
in a real shop we sCOPE the spark to see if its ok.
Fuel pressure, the EFI in this car can not correct bad fuel pressure
its blind to it.
this engine has a very odd TBI
it has a pressure test port
and a FPR pressure adjustment screw.
here are the SM words on this, and I quote.
Fuel pump operating pressure is 14.5 psi (100 kPa). The fuel pressure regulator is adjustable by means of a Torx® head screw on the bottom of the pressure regulator.
- Remove the air cleaner assembly. Remove the screw test port plug on the throttle body, then install a fuel pressure test fitting. Pressure test fittings are available at many auto parts stores.
- Connect an accurate pressure test gauge to the test fitting.
- Connect a tachometer to diagnostic connector terminals D1-1 and D1-3, then start the engine and accelerate it to 2000 rpm.
- Read the fuel pressure on the gauge. If necessary, turn the adjustment screw on the bottom of the fuel pressure regulator to obtain 14.5 psi (100 kPa) of fuel pressure. Turning the screw inward increases the pressure and turning the screw outward decreases the pressure.
- Once all adjustments are complete, install a lead seal ball to cover the regulator adjusting screw. Turn the ignition OFF, then disconnect the tachometer and remove the fuel pressure gauge. Install the original plug screw into the throttle body, then install the air cleaner assembly.
top is test port
bottom is adj screw. (this is like 1st test on rich fuel)
1: cyl compression at spec, WOT.
2: a real tuneup completed ,not just spark plugs. (ICM bad?)
3: ECT reads 300 ohms hot (CTS)
4: fuel pressure at spec. 14.5psi.
5: injector not leaking. (had bad fuel in the last year, or now?)
6: there are no sold scan tools work here, so id have to scope
all ecu pins to find cause. sorry but its sticking RENIX.
has the car sat unused for a year, ? no history
when was car a good daily driver, ? last decade? last week?