I will answer in LINE:
Mechanic shop called while I was responding to your post and said they had swapped the throttle bodies and TPS's. Said car was running great, driven lots, going to drive more etc. About an hour later they called and said "IT'S DOING THE SAME THING!" bogging, etc. (no NOT BOGGING if not BOGGING WOT that is HESITATION only.
So they have left it up to me over the weekend to decide what I want them to do. (well gee fix that hesitation?) they seem so MPI incompentent to me , all cars are MPI what is their problem, your car is SUPER common, in the technical sense, ever try fix cards with 12 computer , wow, that is hard, but NOT THIS CAR.. IMO
A new TB = throttle body is over $1300 at suzuki, and on ebay rare as chicken lips,, in fact 1 there is for 95 and sold as 1998 WRONG NOW.
I am going to try and give you a better time line and series of events to what happened to maybe it will help us both further. First let me say, there was NOTHING wrong the car and the way it ran. NO ISSUES, no bogging no nothing. I was taking care of routine maintenance things that I could not previously afford (time and $$).
1. In April 2019 I had the following done: PCV valve replaced, new crank position sensor (it was in a pkg/ket I had bought with engine seals etc., timing belt replaced, cam and crank seals replaced, water pump replaced, oil pressure switch replaced, new hoses, thermostat replaced (yes correct with rubber seal - YOU HELPED ME WITH THAT ONE!), new air filter and new belts. ALL GOOD
2. I got new tires and wanted alignment. Was told steering eeer box needed replacement, front struts bad, front lower control arm bushings. ALL done. I also asked to check oil leak and it was distributor o rings. FIXED. Also had bad muffler (I did that one), I asked to scan car just see why CEL on (for almost 4 years). Came back with upstream O2 and PO400.
you saw that or they only Report the 1 error, OBD2 can spit out 25 errors, stored
So I decided to replace both O2 sensors and they checked the EGR and said EGR and Switch and Modulator good. They could not get upstream O2 sensor out so told me to take to exhaust shop. I figured po400 stayed on because of front O2 still not replaced. (NO in fact this bad 02, means EGR tests FAIL (false Positives this)
In fact you can drive and let p0400 just happen and see if car runs right, and you said it did not so,,,, needs work.
3. Took to exhaust shop and they couldn't get the front O2 out so created a BUNG hole in the down-pipe between the manifold and the cat and installed the upstream O2 there. Cleared codes. I drove 2-3 days, code popped again. But no drive-ability issues. Was fine.
This was done wrong, I told you all G16 crack #4 header, tube, rear, all do, 99%? not looking there first, bad..
THe correct O2 must be installed, use only BOSCH sensor listed on my page. 4 wire only, with 4 pin connector
The sensor can not work if there are cracks anywhere near it CAN NOT all EFI MPI shops worth salt know this fact, (THE OL error , cruising or at idle proves this !
4. So I decided to replace EGR, EGR switch and modulator - finish the job get rid of code! I also wanted the all the vacum lines replaces just BECAUSE they are 23 years old. That was not done. *****THIS IS WHEN THE hicccup began at idle and I happened to pay attention to the rpm at idle which was about 500. No drive-ability issue, hesitation or bogging...nothing but hiccup at idle. (this was 2/3/20) what you mean is 500 RPM misfire, no G16 runs at 500 rpm AND NOT MISFIRE, back firiing firing Muffler or backfiring to TB is bad timing.
(well this was done wrong or is JUST Coincidental?) hoses wrong is so eash see that 2 tube egr metal pipe there, super easy wrong there.
as is adding new parts wrong, nobody sells that modulator so is it off some Toyota> your old one is good, just clean the vent not ever change out the mOD.
sure a new MAIN EGR is good, to replace at 100k miles. 500 RPM means EGR stuck open (or fueling is bad or spark bad) 3 thing , and 4 bad engine but is not bad engine.
800 RPM Hot, is normal , 1000 cold or 1500 colder is NORMAL, all else is NOT NORMAL.
5. On 2/10/20 is when I apparently got bad gas as that is first time experienced the bogging. I was 20 miles from home and it started on interstate.
well not apparently, it is fact, you said water and rust fell out of filter, so I never LiES...
I got off and went to Advance to scan - only PO400. I put Heat additive in tank thinking my symptoms were bad gas. Drove 10 miles issue cleared up. On 2/11/20, I took to shop to have smoke tested due to PO400 still on and to have check fuel filter cuz suspected bad gas. Smoke good. Only place came out was air box - told me normal. The cleaned the MAF at that time at my request.
the smoke test not for EGR, , but sure finds vacuum leaks... that and that only. DEFEAT The EGR and test the car, the EGR main will stay closed for ever like that and P0400 forever.
forget EGR fix all ELSE FIRST ,and MISFIRING G16 will make the EGR MAP lie and tell you EGR is Bad and IS NOT.. ok> forget the EGR, until (LAST LAST LAST)
This is when tank drained and "wiped" clean, new fuel pump, screen/strainer, fuel filter and gas cap installed. I also decided to have them do plugs, wires, distributor cap and rotor as had not been done in my ownership - probably ever.
Hiccup continued at idle only with idle at 500. (you mean I am sure MISFIRE< and given all the above RICH misfires SO BAD RPM falls 300RPM to 500 RPM, super bad MISFIRE.
6.. I drove car approximately 1 week and suddenly, the bogging started again at 20-25 mph instead of the 65-70 mph on the interstate a week before. It cleared up as I stated. Little heavier pressure on gas pedal and goes! (GOOD full power say has full power WOT) ok?
Drove it several times in order to figure out it did not happen cold or before being at operating temp for 3-5 miles or so. Also found out it pretty much went away after driving another 3-5 miles. Still idles at 500 when stopped at stop, light, etc.
The ISC can stick , hell all do. in time, THE ISC in mounted front of TB mounted to left side of plenum air box, intake manifold, it can be cleaned easy, with carb cleaner,etc
we should just diagnose the 500 RPM this works best.
7. My mechnaic slammed (stumped) so found other shop that will work on older cars. took there 2/21/20. They kept for a week. The replaced IAT and ECT sensors, disassembled intake manifold and cleaned, replaced intake gaskets. DID NOT SOLVE ANYTHING. Did exactly same - $1025 worth of labor and small $$$ of that for parts. Got car back on 2/28/20.
they seem to be EGR centric, and only tried to fix that, ? was EGR the complaint to them or low IDLE HOT?>?
8. Took car back on 3/4/20 and they supposedly found two vacuum lines swapped they did wrong,(wow) checked plug gap and gapped correctly (other shop no gap just slapped em in - i WATCHED! i THOUGHT THEY KNEW SOMETHING i DIDNT), (yep DERPs they are, this car has weak low energy spark not like 2000 cars . 0.028" is correct NGK set them in the automated machine at 0.045" and will misfire that way, BAD BAD BAD...
CHECKED TIMING. Not sure if anything else. Next I know, they said maybe MAF. (yes, it works at idle, if dead DTC sets if weak not) we test it with voltmeter in 5min flat
at idle it reads (per the FSM btw and free to look at in post #1 sticky) here is the volts. 1.0–1.6 volts. at keyon nostart , at idle , and 1.7–2.0 volts) at IDLE, if not bad maf or just dirty.
MAF tests simple here https://fixkick.com/sensors/92-95MAF/92-...sting.html
I waited for confirmation so I could order. Nope...said TPS. I asked if they checked it with meter or whatever and sure it was bad? I was told yes. Not case. Was told today they just thought symptoms of TPS so....
yes TPS fails, for hesitation driving, not WOT< the TPS never makes WOT 95HP fail ever only TIP IN acceleration and never WOT power,loss, ever. ok./
yes mAF fail and are $1000 a SUZUKI real,. after market less, far less, but I never just throw one on, at that cost, no really, when you gun the throttle the maf can hit 3vdc or more on the OUTPUT pin, see link above the tests are so easy, its DC analog voltage simple not FORD PWM magic hear.
9. Today, 3/13/20 Because I had this throttle body and new TPS (which both should have been correct for this car) and we could not locate the correct TPS, decided to try swapping the throttle bodies/TPS to correct. NOPE!!! Ran good then started the bogging same as before. No better. (idle RPM or hesitation or WOT BOGGING???? what still fails)
well you said up top, the mech replace the TB and used the wrong year TB didnt he.
no better and stop saying BOGGING please, bogging is WOT power lost, ok,
BOGGING is like pulling a 10,0oo pound trailer of brakes,
you have simple hesitating.. now the bad news, if you faild to set the TPS calibation like in line 1 above gee, that too causes hesitation (tip in throttle only not wot)
there are 2 ways to fails calibration (feeler gauges, my page on TPS shows the runs on all sidekicks made)
so hear me out try to learn this
1: TPS set wrong and idle switch dead (open circuit foot offf throttle) ISC goes dead, gee that kill hot idle dead, wow, not good
2: TPS set so idle switch opens too late, (hot idle ok, ISC works) and then you move right foot, the ECU then fights you, with ISC , after all it sees idle switch closed, oops set wrong
your calibration step is .026" this is the feeler gauge setting shown here, and how to do it end to end and FSM quotes.
SEE THIS PAGE NOW, for calibrate TPS...[/url]
now see this a bad TPS set right will cause hesitation
a 100 new TPS calibrated wrong, will cause hesitation.
read that 2 times.
new cars now use auto calibration, TPS your car is NOT NEW< tell the DERPS this is 1996-98 not 2004.. ok..
****So they called and left decision to me (too late, closing so be done Monday) -
Leave new throttle body and TPS or put back way was? (wow a $1300 new TB really, where did you find that?// RARE AS HELL THOSE) But rebuilder, CARDONE has them too
I think put back but pends your recommendation and what they gonna charge to put back way was, too. I AM SPENT!!!
That is what happens changing parts not bad, you do it wrong and is not 2 or 3 things wrong not 1. guessing does that, seems that is all do in your shops...
How to proceed from here????
well why not diagnose the problems first. and not guess.. guessing is mess, some get lucky most do not.
ok what I do is not same as others, mine , I have many cars and motorcycles here so down time not an issue for me ever, for 55 years driving, yah
I test then engine and sure smoke test it,sure...
but spark new , compression good, new cam belt, and bad hoses sure, spark timing set with timing freeze jumper in place. -5DEG BTDC? hood sticker tells you.
ok spark good engine good. vacuum solid.. 800 RPM checked..
RPM wrong, what then?, (i clean the ISC electric valve first) this device is what causes 800 to HAPPEN and must not be dead /stuck or packed up with GUNK ever.
I make sure EGR main is closed, if closed IT IS NOT YOURS, THE EGR CAUSING LOW 500 RPM not ever.. if closed, and yours is new..
I see hear engine misfire?, at 500 well sure it will EFI hates 500 RPM as does MAP sensor ! hot, engine tests only.. 500 RPM is fix me first thing, on this CAR
I then raise, idle by hand to 800 RPM, OMG the misfire ended, good , if not injections bad, (fueling ) or spark bad.. more test. more tests not guessing.
see how easy that test is above, line???????????
still misfires, darn.
i put my timing light on the 4 plug wires 1 by 1, at force 800 rpm by hand missing, do I see 1 wire shows blinking timing light shows misfire, NO then it is fueling wrong (rich i bet)
blink blink miss, blink (this is bad,) seen on any timing light, (so easy to do at spark wires with inductive clip of tool)
I gander at my SCAN tool dang the OL status stuck there, does CL open loop happen now if you force 800rpm, by hand if misfiring no 02 works right, not really,
I push pending button on the scan tool and wow more codes,? there (forget 400s see others first) tell me them
I check fuel pressure keyon and idle , pass fail.
pass. (if fail fix that next FIRST ) bad fuel pressure is always a fix first event, called Basics.
is the O2 dead? scanned..
I scan loop test the front 02, rear is useless here) my tool as O2 meter mode, creates at 02 scope view to see SWINGS.
The sensor 02 must swing and show 0.1 to near 0.9v signals, if not?, the O2 is dead, (or exhaust cracks near by O2 front)
The ASE classes tell you now try to force this rich running engine lean ( using the magic trick cause vacuum leak on purpose now, this act causes LEAN as you do that you .
on this car the tiny vacuum lines at the plenum box front are prime targets to pull and cause small vacuum leak. (intake manifold front plenum box)
see if the O2 scans show the 02 wake up?, if not 02 is bad. or engine so rich (AFR) that we are doomed, (example leaking injectors are fuel pressure 60psi dead dead WRONG)
the goal is not EGR, forget EGR , they sell these cars with nO EGR at all on some islands ? JDM versions. (if you keep it closed that main valve this is not your problems)
but the goal is get 800rpm to happen... here is the list.
first clean the ISC (remove it clean it, it must never be dead nor stuck closed, and air must flow opened)
[url=https://fixkick.com/sensors/tests/IAC-E-tests.html]then calibrate the TPS you mech is clueless about that I guess.
find cause of 500rpm, this is first order symptoms,,
see if idle misfire goes away if hand moved throttle valve causes 800 rpm now, and misfire ends , does it?, this is key fact here.
500 RPM is caused by dead ISC (TPS calibration) or fueling wrong if spark is ok.
this is the path to work. IMO. good luck !!! This is how i do this, how you do it or 3rd party, IDK..
Mechanic shop called while I was responding to your post and said they had swapped the throttle bodies and TPS's. Said car was running great, driven lots, going to drive more etc. About an hour later they called and said "IT'S DOING THE SAME THING!" bogging, etc. (no NOT BOGGING if not BOGGING WOT that is HESITATION only.
So they have left it up to me over the weekend to decide what I want them to do. (well gee fix that hesitation?) they seem so MPI incompentent to me , all cars are MPI what is their problem, your car is SUPER common, in the technical sense, ever try fix cards with 12 computer , wow, that is hard, but NOT THIS CAR.. IMO
A new TB = throttle body is over $1300 at suzuki, and on ebay rare as chicken lips,, in fact 1 there is for 95 and sold as 1998 WRONG NOW.
I am going to try and give you a better time line and series of events to what happened to maybe it will help us both further. First let me say, there was NOTHING wrong the car and the way it ran. NO ISSUES, no bogging no nothing. I was taking care of routine maintenance things that I could not previously afford (time and $$).
1. In April 2019 I had the following done: PCV valve replaced, new crank position sensor (it was in a pkg/ket I had bought with engine seals etc., timing belt replaced, cam and crank seals replaced, water pump replaced, oil pressure switch replaced, new hoses, thermostat replaced (yes correct with rubber seal - YOU HELPED ME WITH THAT ONE!), new air filter and new belts. ALL GOOD
2. I got new tires and wanted alignment. Was told steering eeer box needed replacement, front struts bad, front lower control arm bushings. ALL done. I also asked to check oil leak and it was distributor o rings. FIXED. Also had bad muffler (I did that one), I asked to scan car just see why CEL on (for almost 4 years). Came back with upstream O2 and PO400.
you saw that or they only Report the 1 error, OBD2 can spit out 25 errors, stored
So I decided to replace both O2 sensors and they checked the EGR and said EGR and Switch and Modulator good. They could not get upstream O2 sensor out so told me to take to exhaust shop. I figured po400 stayed on because of front O2 still not replaced. (NO in fact this bad 02, means EGR tests FAIL (false Positives this)
In fact you can drive and let p0400 just happen and see if car runs right, and you said it did not so,,,, needs work.
3. Took to exhaust shop and they couldn't get the front O2 out so created a BUNG hole in the down-pipe between the manifold and the cat and installed the upstream O2 there. Cleared codes. I drove 2-3 days, code popped again. But no drive-ability issues. Was fine.
This was done wrong, I told you all G16 crack #4 header, tube, rear, all do, 99%? not looking there first, bad..
THe correct O2 must be installed, use only BOSCH sensor listed on my page. 4 wire only, with 4 pin connector
The sensor can not work if there are cracks anywhere near it CAN NOT all EFI MPI shops worth salt know this fact, (THE OL error , cruising or at idle proves this !
4. So I decided to replace EGR, EGR switch and modulator - finish the job get rid of code! I also wanted the all the vacum lines replaces just BECAUSE they are 23 years old. That was not done. *****THIS IS WHEN THE hicccup began at idle and I happened to pay attention to the rpm at idle which was about 500. No drive-ability issue, hesitation or bogging...nothing but hiccup at idle. (this was 2/3/20) what you mean is 500 RPM misfire, no G16 runs at 500 rpm AND NOT MISFIRE, back firiing firing Muffler or backfiring to TB is bad timing.
(well this was done wrong or is JUST Coincidental?) hoses wrong is so eash see that 2 tube egr metal pipe there, super easy wrong there.
as is adding new parts wrong, nobody sells that modulator so is it off some Toyota> your old one is good, just clean the vent not ever change out the mOD.
sure a new MAIN EGR is good, to replace at 100k miles. 500 RPM means EGR stuck open (or fueling is bad or spark bad) 3 thing , and 4 bad engine but is not bad engine.
800 RPM Hot, is normal , 1000 cold or 1500 colder is NORMAL, all else is NOT NORMAL.
5. On 2/10/20 is when I apparently got bad gas as that is first time experienced the bogging. I was 20 miles from home and it started on interstate.
well not apparently, it is fact, you said water and rust fell out of filter, so I never LiES...
I got off and went to Advance to scan - only PO400. I put Heat additive in tank thinking my symptoms were bad gas. Drove 10 miles issue cleared up. On 2/11/20, I took to shop to have smoke tested due to PO400 still on and to have check fuel filter cuz suspected bad gas. Smoke good. Only place came out was air box - told me normal. The cleaned the MAF at that time at my request.
the smoke test not for EGR, , but sure finds vacuum leaks... that and that only. DEFEAT The EGR and test the car, the EGR main will stay closed for ever like that and P0400 forever.
forget EGR fix all ELSE FIRST ,and MISFIRING G16 will make the EGR MAP lie and tell you EGR is Bad and IS NOT.. ok> forget the EGR, until (LAST LAST LAST)
This is when tank drained and "wiped" clean, new fuel pump, screen/strainer, fuel filter and gas cap installed. I also decided to have them do plugs, wires, distributor cap and rotor as had not been done in my ownership - probably ever.
Hiccup continued at idle only with idle at 500. (you mean I am sure MISFIRE< and given all the above RICH misfires SO BAD RPM falls 300RPM to 500 RPM, super bad MISFIRE.
6.. I drove car approximately 1 week and suddenly, the bogging started again at 20-25 mph instead of the 65-70 mph on the interstate a week before. It cleared up as I stated. Little heavier pressure on gas pedal and goes! (GOOD full power say has full power WOT) ok?
Drove it several times in order to figure out it did not happen cold or before being at operating temp for 3-5 miles or so. Also found out it pretty much went away after driving another 3-5 miles. Still idles at 500 when stopped at stop, light, etc.
The ISC can stick , hell all do. in time, THE ISC in mounted front of TB mounted to left side of plenum air box, intake manifold, it can be cleaned easy, with carb cleaner,etc
we should just diagnose the 500 RPM this works best.
7. My mechnaic slammed (stumped) so found other shop that will work on older cars. took there 2/21/20. They kept for a week. The replaced IAT and ECT sensors, disassembled intake manifold and cleaned, replaced intake gaskets. DID NOT SOLVE ANYTHING. Did exactly same - $1025 worth of labor and small $$$ of that for parts. Got car back on 2/28/20.
they seem to be EGR centric, and only tried to fix that, ? was EGR the complaint to them or low IDLE HOT?>?
8. Took car back on 3/4/20 and they supposedly found two vacuum lines swapped they did wrong,(wow) checked plug gap and gapped correctly (other shop no gap just slapped em in - i WATCHED! i THOUGHT THEY KNEW SOMETHING i DIDNT), (yep DERPs they are, this car has weak low energy spark not like 2000 cars . 0.028" is correct NGK set them in the automated machine at 0.045" and will misfire that way, BAD BAD BAD...
CHECKED TIMING. Not sure if anything else. Next I know, they said maybe MAF. (yes, it works at idle, if dead DTC sets if weak not) we test it with voltmeter in 5min flat
at idle it reads (per the FSM btw and free to look at in post #1 sticky) here is the volts. 1.0–1.6 volts. at keyon nostart , at idle , and 1.7–2.0 volts) at IDLE, if not bad maf or just dirty.
MAF tests simple here https://fixkick.com/sensors/92-95MAF/92-...sting.html
I waited for confirmation so I could order. Nope...said TPS. I asked if they checked it with meter or whatever and sure it was bad? I was told yes. Not case. Was told today they just thought symptoms of TPS so....
yes TPS fails, for hesitation driving, not WOT< the TPS never makes WOT 95HP fail ever only TIP IN acceleration and never WOT power,loss, ever. ok./
yes mAF fail and are $1000 a SUZUKI real,. after market less, far less, but I never just throw one on, at that cost, no really, when you gun the throttle the maf can hit 3vdc or more on the OUTPUT pin, see link above the tests are so easy, its DC analog voltage simple not FORD PWM magic hear.
9. Today, 3/13/20 Because I had this throttle body and new TPS (which both should have been correct for this car) and we could not locate the correct TPS, decided to try swapping the throttle bodies/TPS to correct. NOPE!!! Ran good then started the bogging same as before. No better. (idle RPM or hesitation or WOT BOGGING???? what still fails)
well you said up top, the mech replace the TB and used the wrong year TB didnt he.
no better and stop saying BOGGING please, bogging is WOT power lost, ok,
BOGGING is like pulling a 10,0oo pound trailer of brakes,
you have simple hesitating.. now the bad news, if you faild to set the TPS calibation like in line 1 above gee, that too causes hesitation (tip in throttle only not wot)
there are 2 ways to fails calibration (feeler gauges, my page on TPS shows the runs on all sidekicks made)
so hear me out try to learn this
1: TPS set wrong and idle switch dead (open circuit foot offf throttle) ISC goes dead, gee that kill hot idle dead, wow, not good
2: TPS set so idle switch opens too late, (hot idle ok, ISC works) and then you move right foot, the ECU then fights you, with ISC , after all it sees idle switch closed, oops set wrong
your calibration step is .026" this is the feeler gauge setting shown here, and how to do it end to end and FSM quotes.
SEE THIS PAGE NOW, for calibrate TPS...[/url]
now see this a bad TPS set right will cause hesitation
a 100 new TPS calibrated wrong, will cause hesitation.
read that 2 times.
new cars now use auto calibration, TPS your car is NOT NEW< tell the DERPS this is 1996-98 not 2004.. ok..
****So they called and left decision to me (too late, closing so be done Monday) -
Leave new throttle body and TPS or put back way was? (wow a $1300 new TB really, where did you find that?// RARE AS HELL THOSE) But rebuilder, CARDONE has them too
I think put back but pends your recommendation and what they gonna charge to put back way was, too. I AM SPENT!!!
That is what happens changing parts not bad, you do it wrong and is not 2 or 3 things wrong not 1. guessing does that, seems that is all do in your shops...
How to proceed from here????
well why not diagnose the problems first. and not guess.. guessing is mess, some get lucky most do not.
ok what I do is not same as others, mine , I have many cars and motorcycles here so down time not an issue for me ever, for 55 years driving, yah
I test then engine and sure smoke test it,sure...
but spark new , compression good, new cam belt, and bad hoses sure, spark timing set with timing freeze jumper in place. -5DEG BTDC? hood sticker tells you.
ok spark good engine good. vacuum solid.. 800 RPM checked..
RPM wrong, what then?, (i clean the ISC electric valve first) this device is what causes 800 to HAPPEN and must not be dead /stuck or packed up with GUNK ever.
I make sure EGR main is closed, if closed IT IS NOT YOURS, THE EGR CAUSING LOW 500 RPM not ever.. if closed, and yours is new..
I see hear engine misfire?, at 500 well sure it will EFI hates 500 RPM as does MAP sensor ! hot, engine tests only.. 500 RPM is fix me first thing, on this CAR
I then raise, idle by hand to 800 RPM, OMG the misfire ended, good , if not injections bad, (fueling ) or spark bad.. more test. more tests not guessing.
see how easy that test is above, line???????????
still misfires, darn.
i put my timing light on the 4 plug wires 1 by 1, at force 800 rpm by hand missing, do I see 1 wire shows blinking timing light shows misfire, NO then it is fueling wrong (rich i bet)
blink blink miss, blink (this is bad,) seen on any timing light, (so easy to do at spark wires with inductive clip of tool)
I gander at my SCAN tool dang the OL status stuck there, does CL open loop happen now if you force 800rpm, by hand if misfiring no 02 works right, not really,
I push pending button on the scan tool and wow more codes,? there (forget 400s see others first) tell me them
I check fuel pressure keyon and idle , pass fail.
pass. (if fail fix that next FIRST ) bad fuel pressure is always a fix first event, called Basics.
is the O2 dead? scanned..
I scan loop test the front 02, rear is useless here) my tool as O2 meter mode, creates at 02 scope view to see SWINGS.
The sensor 02 must swing and show 0.1 to near 0.9v signals, if not?, the O2 is dead, (or exhaust cracks near by O2 front)
The ASE classes tell you now try to force this rich running engine lean ( using the magic trick cause vacuum leak on purpose now, this act causes LEAN as you do that you .
on this car the tiny vacuum lines at the plenum box front are prime targets to pull and cause small vacuum leak. (intake manifold front plenum box)
see if the O2 scans show the 02 wake up?, if not 02 is bad. or engine so rich (AFR) that we are doomed, (example leaking injectors are fuel pressure 60psi dead dead WRONG)
the goal is not EGR, forget EGR , they sell these cars with nO EGR at all on some islands ? JDM versions. (if you keep it closed that main valve this is not your problems)
but the goal is get 800rpm to happen... here is the list.
- spark is bad 1 to 4 or all 4. misfire from bad spark, or timed wrong.
- the ISC is dead or the TPS idle switch dead or set wrong..
- the engine is rich misfiring, (lots of reasons..) and tests
- the engine is lean and runs slow at idle, not common but vacuum leaks huge, no was smoke tested
- injectors clogged, WOT only , your car, passes so can only be rich misfire...
- leaking injectors there is leak down test in the FSM. 96 free ,post 1. fueling.
- my guess the front 02 is dead, now. i test it fully. Find out why it is dead, misifire gross can do that..
first clean the ISC (remove it clean it, it must never be dead nor stuck closed, and air must flow opened)
[url=https://fixkick.com/sensors/tests/IAC-E-tests.html]then calibrate the TPS you mech is clueless about that I guess.
find cause of 500rpm, this is first order symptoms,,
see if idle misfire goes away if hand moved throttle valve causes 800 rpm now, and misfire ends , does it?, this is key fact here.
500 RPM is caused by dead ISC (TPS calibration) or fueling wrong if spark is ok.
this is the path to work. IMO. good luck !!! This is how i do this, how you do it or 3rd party, IDK..
http://www.fixkick.com