FAQ: Hesitation, Stutter(Studder), Shudder, Stumbling, on Acceleration/Load

I am thinking pull the throttle body and clean/reset or replace the IAC valve.

sniperdude wrote:

200 bones to scan the car is BS.

A low cost thing worth looking into is your IACV (idle air control valve). Perhaps take a look at the throttle body, give it a nice cleaning, clean the IACV out with some of that CRC cleaner and a toothbrush and reset the pintle before reinstallation. If it's gummed up your idle will be bad (shuddering, etc)

You'll need a gasket if you're gonna take off the throttle body BTW.

I had a grand cherokee with a bad IACV and it felt like an earthquake was going on at idle, and after replacement it worked great.

Oh yeah, and about that oil light - if you're positive that your engine has proper oil pressure and your pump is good, I bet your oil pressure switch is bad.

The dealers here are bogus except for batteries and oil change work prices. local places have never fixed anything right when i brought it in i always went back at least twice...

also i noticed you live close to me so i was wondering what your guys are charging out there to scan or do you own a scanner? if you do own one i desperately need to findout what model is good for the 95's to figure out my ABS as my brakes are complete shit since the line repair and even after bleeding. I suspect there is air in the ABS pump deal.

AA wrote:

Have you replaced the plug wires and spark plugs?

no but i bought stock delco wireset and autolite 104's and a crank sensor which was also delco for a deal at $65 bucks on advanceautoparts.com found some promocode on google that saved me 50 bucks. Just came in mail today. I plan on doing that tomorrow.

now i am pretty motor savvy on my motorcycles but cars i get flustered with alot. Now I will take this apart tomorrow also but what do you mean by reset?

Nice work. I'd go ahead and install the plugs and wires. See if there's any improvement before you start messing with the crank sensor.

[quote="AA"]Have you replaced the plug wires and spark plugs?[/quote

I also wonder if you are running regular or premium gas.

[quote="albertj"]

AA wrote:

Have you replaced the plug wires and spark plugs?[/quote

I also wonder if you are running regular or premium gas.

Always premium and a can of seafoam every 10 fillups

AA wrote:

Nice work. I'd go ahead and install the plugs and wires. See if there's any improvement before you start messing with the crank sensor.

Yea because like i stated i bought a new one but hear its not that easy and something having to with setting it after its installed if that sounds correct

also i recall but cant find now in the forum something about a wire harness i can buy online that supports the obd 1.5 system that i can run off my laptop if that sounds correct? if their is could ya help in guiding me to that product and software...please and thanku

*EDIT ok the Actron 9145 i found i can use but it doesnt read ABS codes. Any idea how to do that on the 95"s or am i stuck going to a dealer?

A dealer is your best bet with ABS codes.

I'm not sure if this will work on our Riv's - but I've heard of being able to have the lights flash out the codes.

You could try to read the flashes by shorting Pin 9 to Pin 5 on the OBD2 diag connector, but I'm not sure if it'll read out the ABS codes. I know it will on other ALDL cars like the vette.

This guide is for an OBD1.5 S10, but it should be relatively the same.

Somebody else can chime in, but this is what it says:

Ground Pin 9 on the ODB conn. to Pin 5 (GND).



Turn ignition ON but do not start the engine. The Anti-lock lamp will come on for four seconds, and then blink the 1-2 code followed by each stored trouble code. A 1-2 code is not a fault code; it indicates proper operation of the system. All codes are two digits. If you cannot extract codes this way, you might have a significant problem and MUST diagnose with the proper scan tool. Codes will auto clear after 100 ignition cycles with no code set.


OBD1.5 CODES:
CODE 21 - FRONT RIGHT SENSOR CIRCUIT OPEN/SHORTED
CODE 22 - INTERMITTENT SIGNAL, FRONT RIGHT SENSOR
CODE 23 - MISSING SIGNAL, FRONT RIGHT SENSOR
CODE 24 - NOT USED
CODE 25 - FRONT LEFT SENSOR CIRCUIT OPEN/SHORTED
CODE 26 - INTERMITTENT SIGNAL, FRONT LEFT SENSOR
CODE 27 - MISSING SIGNAL, FRONT LEFT SENSOR
CODE 28 - NOT USED
CODE 31 - REAR RIGHT SENSOR CIRCUIT OPEN/SHORTED
CODE 32 - INTERMITTENT SIGNAL, RIGHT REAR SENSOR
CODE 33 - MISSING SIGNAL, REAR RIGHT SENSOR
CODE 34 - NOT USED
CODE 35 - REAR LEFT SENSOR CIRCUIT OPEN/SHORTED
CODE 36 - INTERMITTENT SIGNAL, REAR LEFT SENSOR
CODE 37 - MISSING SIGNAL, REAR LEFT SENSOR
CODE 38 - NOT USED
CODE 41 - ELECTRICAL DISTURBANCE INLET VALVE (CIRCUIT - FRONT RIGHT)
CODE 42 - ELECTRICAL DISTURBANCE OUTLET VALVE (CIRCUIT - FRONT RIGHT)
CODE 44 - ELECTRICAL DISTURBANCE ISOLATION VALVE SV1 (CIRCUIT - FRONT LEFT)
NOTE: TCS ONLY
CODE 44 - NOT USED
CODE 45 - ELECTRICAL DISTURBANCE INLET VALVE (CIRCUIT - FRONT LEFT)
CODE 46 - ELECTRICAL DISTURBANCE OUTLET VALVE (CIRCUIT - FRONT LEFT)
CODE 48 - ELECTRICAL DISTURBANCE ISOLATION VALVE SV2 (CIRCUIT -FRONT RIGHT)
NOTE: TCS ONLY
CODE 49 - NOT USED
CODE 51 - ELECTRICAL DISTURBANCE INLET VALVE (CIRCUIT - REAR RIGHT)
CODE 52 - ELECTRICAL DISTURBANCE OUTLET VALVE (CIRCUIT - REAR RIGHT)
CODE 55 - ELECTRICAL DISTURBANCE INLET VALVE (CIRCUIT - REAR LEFT)
CODE 56 - ELECTRICAL DISTURBANCE OUTLET VALVE (CIRCUIT - REAR LEFT)
CODE 62 - PUMP PRESSURE FAULT DURING ABS STOP
CODE 61 - PUMP MOTOR RUN FAULT
CODE 71 - CHECKSUM ERROR
CODE 72 - TRAVEL SWITCH INPUT NOT PROCESSABLE
CODE 73 - FLUID LEVEL SWITCH INPUT NOT PROCESSABLE
CODE 74 - PMV PRESSURE SWITCH CIRCUIT
NOTE: TCS ONLY
CODE 75 - PCM REQUESTED TCS DISABLE
NOTE: TCS ONLY
CODE 76 - UART SDL CIRCUIT/SIGNAL
CODE 77 - DELIVERED TORQUE PWM CIRCUIT/SIGNAL
NOTE: TCS ONLY

I'm actually working on a project to build a reader for the 95, but it will take a while before I can confirm if it works or not.

okay so the new plugs and wires got put in today. I havent removed the throttle body yet as the gasket is on order to be here tomorrow. Anyhow the car still sucks. It cuts out at 4000ish rpm's in park and rev'n.it. by listening to exhaust and the cold air intake it sounds like something is still misfiring. the cold air used to have a high pitch whine and gurgle and now its sputs something nasty. it does not accelerate any better than damn toyota tercel. Its embarrassing to drive it to be honest. Will the throttle body being cleaned up help this? Im sorry but to be blunt its absolutely F'n bullshit the way this car goes from a speeding bullet to straight POS, and I dont abuse the car either!... absolutely baffling at this point...

Is there a way to test the coil packs with an ohm meter? thats my next route...
thanks for the reply's as any insight is better than where i am sitting right now.

When you say it cuts out at 4K RPMs you mean the motor dies? Or does you mean it's hitting the rev limiter? I believe the car in park has a limiter at 4K.

I suspect the MAF as well. You said it got a little bit better after you cleaned it up.

Try unplugging it and see how it runs. Do not hard rev it.

If it gets better it might be time to pick up a new one. I would still go ahead with the TB and IACV cleaning.

any thing i should be cautious about when removing the TB or special tools? i only see like 3 10mm nuts holding it on if that sounds right but a bunch of linkage connected? im pulling it off tonight i guess. nor do i know how to reset this pintle you describe.
im gonna go disconnect now and see what it does and let ya know.

unplugged maf it it wanted to die but didnt just low rpms and so i gave it a lil gas and it took a about 15 seconds for it to catch itself back to a steady idle and ran fine but i can still hear something not smooth. like a (now say this fast so you understand.lol) chuh chuh chuh chuh chuh chuh chuh.

Yeah the PCM was adjusting to reading without the MAF.

Sounds like you have multiple issues. Are you running premium gas?

Also the tb I haven't taken mine apart yet, but I know people have mentioned something about a black bracket blocking the way of removing the tb?

To reset the pintle you push the pintle head back in towards the sensor. When it gets reinstalled the computer will adjust the valve pintle to what it needs.

Also worth mentioning, maybe Unplug your battery after these repairs to reset the ECU.

hey snipes i just went to parts store and bought a inline spark checker bulb deal and the gf turn on and off the car through all 6 coil pack prongs and the number 1 is faulty as hell. hopefully the coil pack will fix my issue.im buying it tomorrow and slapping it on. hopefully sweet victory. i will reup the post later

Ok but it could be the wiring that goes to the coils. I think there's a thread on here about that. Like broken wires or something. Supposedly the coil packs are very hardy and hard to kill.

my wiring is actually super clean but i will inspect if the new pack fails. i have 240000 miles on my riv and the coils appear stock as they still have the numbers on them for cylinder order.

Quote :

i just went to parts store and bought a inline spark checker bulb deal and the gf turn on and off the car through all 6 coil pack prongs and the number 1 is faulty as hell. hopefully the coil pack will fix my issue.im buying it tomorrow and slapping it on. hopefully sweet victory. i will reup the post later

Because the coil drives both cylinders 1 & 4, if that coil is bad both cylinders will test at fault. If you're only seeing a problem with #1, I would still be looking at plug & wire on cylinder 1. Maybe swap 1 and 4 at the coil and see if anything changes.

AA wrote:

Because the coil drives both cylinders 1 & 4, if that coil is bad both cylinders will test at fault. If you're only seeing a problem with #1, I would still be looking at plug & wire on cylinder 1. Maybe swap 1 and 4 at the coil and see if anything changes.

ok confused now. the tool i used ran inbetween then new wire and the coil pack. So therefore if im hearing you correctly the coils not bad and i should check the wiring to it? the bulb lit but it was super dim and didnt show much of a pulse at idle. to give you an idea of the bulbs brightness the number 1 was showing maybe 5% brightness as compared to the other 5.

maybe a wire melted underneath or something i will check in morning as changing the plugs on the back 3 were enough to make me drink a few. isnt there a contact plate underneath the coils that can be damaged or anyother reason that number 1 coil doesnt fire if the wires going to the coil arent damaged just so i know where to look next for an issue?

I would swap wires 1 & 4 at the coil then do the test again. See if it moves. It's a waste spark system, so each coil sends spark to a pair of cylinders at a time.

As of recently i have been getting shuttering and stalling at highway speeds and at stops. I checked recent codes and i got
p0341 Cam/Cranks Error
p0321 Spark Reference circuit
p1361 Ignition Control Signal not toggling
p0740 TCC Failure
p1406 EGR Pintle Position Circuit

I'm not really sure where to start. Could this be a bad cam sensor causing all of these issues? I did notice the tcc stop working the other day, but i has since not given me problems. thanks for any help

It may be a bad ground issue. Have that checked! Unlikely all those things could go bad at once.

AA wrote:

Quote :

i just went to parts store and bought a inline spark checker bulb deal and the gf turn on and off the car through all 6 coil pack prongs and the number 1 is faulty as hell. hopefully the coil pack will fix my issue.im buying it tomorrow and slapping it on. hopefully sweet victory. i will reup the post later

Because the coil drives both cylinders 1 & 4, if that coil is bad both cylinders will test at fault. If you're only seeing a problem with #1, I would still be looking at plug & wire on cylinder 1. Maybe swap 1 and 4 at the coil and see if anything changes.

pulled coil and put dielectric grease on and tested spark again. still no spark on number one but the other side fired just fine. Installed new coil pack and applied dielectric grease to it again(more lube the beter right?) started up great, sounds great, runs great. Took it on a shakedown run after warmup and sure enough the power is back to what it was if not a tad better than I recall. Glad i didnt have to chase wiring and it was the coil pack that was no bueno.
Thanks for the help