Hi I've been having problems with my 91 cutlass ciera. It is the 3100 V6 engine. It has about 88k miles. The SES light is not on and no trouble codes are stored. The problem is when the engine is cold, it stalls out when idling, but especially when coming to stops, after it warms up it doesnt do it. It also has a rough idle and hesitation when you accelerate. Also there is a ticking coming from somewhere (seems to be everywhere, but I think the intake, injectors maybe?) So far I've done this:
New MAF
New plugs/wires
New Fuel Filter
New Air Filter
New Fuel Injectors
Raised Idle screw
Cleaned IAC out
Cleaned MAF
Cleaned throttle body
Replaced cracked vac hoses
Checked Coil packs

I checked the TPS and coolant sensor and they seemed to be fine but im gonna grab some new ones anyway and see if that works (4 junkyards 2 minutes from my house). I tried looking for the damn PCV valve on the car but im convinced it doesnt have one. The only thing is a line coming off the front valve cover and its just a metal tube then goes to rubber in the intake. And it doesnt look like it has an EGR either, I thought it had one but it turned out thats the fuel pressure regulator. So anyone know what else it could be? Clogged cat? Crank sensor? Anyone know where the PVC valve is??

Welcome to AF. Did you scan it and look at the coolant temp sensor readings cold, when you changed the base idle setting you also changed the tps adjustment, this is not supposed to be moved, you will have to readjust it and check the tps setting. Go to autozone.com, repair guides for component locations and adjustment/check procedures.

I was certain that the 91 ciera used the 3300 90 degree v6, but maybe thats cuz your car is american... i dont know, but the 3300 doesnt use the conventional egr set-up... injectors are usually loud, no worries there... maek sure you get the right temp sensor, and not just the temp sender for the gauges...

the pcv valve on a 3100 is clearly visible on the front rocker cover, leading me once more to suspect your talking about a different motor... on a 3300 engine the PCV is well hidden... standing in front of the car, it's located on the intake manifold to the left side and toward the back... it's a real pain to get out, and you'll likely break something, so be careful...

OOPS my mistake, it is the 3300 motor, heres a pic of one:
http://geocities.com/billychiesi/3300.jpg

It had this problem before I raised the idle, I raised it so it wouldn't stall as often. I didnt scan it i just jumped a and b and no codes. I tried autozone's method of checking the TPS, but I think their method is wrong b/c I got a reading of 0 volts, heres what it says:



Remove air cleaner. Disconnect the TPS harness from the TPS.
Using suitable jumper wires, connect a digital voltmeter J-29125-A or equivalent to the correct TPS terminals A and B.
With the ignition ON and the engine running, The TPS voltage should be 0.3-1.0 volts at base idle to approximately 4.5 volts at wide open throttle.
If the reading on the TPS is out of specification, check the minimum idle speed before replacing the TPS.
If the voltage reading is correct, remove the voltmeter and jumper wires and reconnect the TPS connector to the sensor.
Reinstall the air cleaner.

Now I thought you were supposed to leave the harness ON to check the voltage? So I mean you have to cut into the insulation to do that then?


I looked all over for the pvc and egr, but I couldnt find it, i guess i'll look again. The thing coming off the front valve cover isn't a pcv its just a tube. Tell me about breaking stuff on this car, i've broken so many screws, gm is so stupid this cast aluminum stuff just locks them on, even with tons of penetrating spray and vice grips its a PITA.

Edit: I'm also gonna check the fuel pressure and make sure its not the pump, can a tire guage be used in a pinch (lol)? I also heard the PCV is behind the alternator on the intake, i'll look again and change that out. I also gotta get a new grommet for that tube coming off the front valve cover, i broke it and part of it fell inside, and I just got it electric taped up right now lol..

Yeah you are not supposed to adjust the idle screw :nono:
Now the ecu is getting faulty readings.

Now I thought you were supposed to leave the harness ON to check the voltage? So I mean you have to cut into the insulation to do that then?
On testing any voltages you need to back probe the connectors with a straight pin or something small.

With the 0 volts reading the TPS, I'd say its not working.

Also with rough idle and hesitation when you accelerate, I'd test the IAC just make sure its working properly.

So leave the harness ON when testing the TPS? Then I just re adjust the idle screw so its in the voltage range? (.3-.5v right?) How do I test the IAC? I'm gonna clean the coolant sensor and replace the pvc valve today.

Alright, I got some carb cleaner and completly cleaned out the throttle body and IAC and everything again, and I checked for vac leaks with it too. I tightened the intake down. I put a hose clamp on the brake booster cos it didn't have one, I thought maybe it was leaking. I replaced the pvc. It still stalls out like when I come to a stop itll start dying and I gotta press the gas a little. It does this until the engine warms. But there is also this hesitation when accelerating at part throttle, itll just fall on its face and buck and surge. Most of the time I accelerate quickly just because its annoying. I'm gonna replace the IAC because I think it might be faulty, but its just a hunch. Whats the right way to test the TPS??

Remove air cleaner. Disconnect the TPS harness from the TPS.
Using suitable jumper wires, connect a digital voltmeter J-29125-A or equivalent to the correct TPS terminals A and B.
With the ignition ON and the engine running, The TPS voltage should be 0.3-1.0 volts at base idle to approximately 4.5 volts at wide open throttle.
If the reading on the TPS is out of specification, check the minimum idle speed before replacing the TPS.
If the voltage reading is correct, remove the voltmeter and jumper wires and reconnect the TPS connector to the sensor.
Reinstall the air cleaner.

You stick wires(jumpers) in the plug in, then plug it to the tps and test.

the SES light came on once then turned off today, I got a code 13, and a code 34. Hesitation problem seems to be getting worse, it only happens at like 20-40% throttle apprx

OBD - 13 Oxygen Sensor(O2s)Circuit - open circuit
- 34 Manifold Absolute Pressure(MAP) Sensor circuit signal voltage low
- or 34 Mass Air Flow Sensor Circuit-low frequency

And from what you are saying about the throtle position, did you ever test your TPS ?

I try swapping the maf again, but i dont think thatll do anything, and ill try getting a few o2 sensors and test the tps. Its just too friggen cold outside right now! :banghead:

hey rayzor im having a similar problem same year and engine (91 cutlass ciera 3.3L v6) heres a link to mine to maybe give some ideas and if anyone has any suggestions im gonna keep my eye on both forums

http://www.automotiveforums.com/vbulletin/showthread.php?t=852994

I would suggest you both check for bad wiring(shorts) in the ignition system and or intake manifold leaks(loose bolts/nuts) or vacum leaks on any hoses.
Could also just be from clogged/dirty or bad injectors, which I probley have said already.

Also the MAF wires are usualy stretched out and can get damaged too, which will cause all sorts of troubles.

I would suggest you both check for bad wiring(shorts) in the ignition system and or intake manifold leaks(loose bolts/nuts) or vacum leaks on any hoses.
Could also just be from clogged/dirty or bad injectors, which I probley have said already.

Also the MAF wires are usualy stretched out and can get damaged too, which will cause all sorts of troubles.
I checked for vac leaks with carb cleaner, and replaced any cracked hoses. Its not the injectors, and I tightened the manifold down. The maf wires are clean but they could have been stretched i'll try getting another one but i dont think thats the problem. I think i might have a bad tps (causing the hesitation) and a bad IAC b/c the engine made the biggest improvement when i cleaned it out, and one time the idle just went out of control i thought the engine was gonna blow. Not sure but coolant sensor also may be bad because it doesnt stall when it warms up but it still hesitates. I dont think its an o2 cos it doesnt smell like rotten eggs, but its probably due for a new one. Can i just grab an o2 from the boneyard n clean it? or should i just get a new one theyre kinda expensive

Also i tested the coil packs by holding the spark plug above it n looking for spark on each one, I noticed one wasnt quite as strong so i replaced it. Is it okay to just replace one or you ahve to all of them? It didnt really make any improvement.

time for a fuel pump and a fuel filter. Also check the vac line to the trans, and the FPR for good measure.... but anyways, fuel pump im going to say.

How do i check the vac line to the trans? Fuel filter is brand new, and its not a fuel pressure problem my mechanic said. I'm gonna try replacing the IAC, TPS, and coolant sensor and report back..

Do you have a multi-meter? They are cheap.

The most glaring thing i see is an OPEN circuit in the O2 sensor (either the sensor is open or the open is in the wiring somewhere). I would really check the wiring to all three circuits w/ the meter on the resistance setting and the suspect wiring isolated (disconnected at both ends @ component)..only do a resistance check with power OFF, could damage the meter. meters are cheap @ any hardware store. Even if the wiring is good, any exposed wire or insulation cut away could be rubbing against something and shorting or grounding. So, you might want to pull the wire out of the conduit and check EVERY inch for visual signs of melting, exposed copper wire, burn marks, scrapes, frayed wire and wire that may be completely severed.

zeroinfinity was spot on with my shorting problem.

Pardon my ignorance if you know how to use a meter. If not, the meter should come with instructions on how to use it or possibly your service manual in electrical troubleshooting.

resistance tests are always done on a DEAD circuit. You don't want power going through when testing for resistance.

I have a small multi meter, the car caught on fire once before from the injector o rings before, but nothing was really damaged other than the wires coming off the injectors which i replaced. But this problem was going on before then, ill check the O2 sensor wire. Are you talking about just checking the o2 sensor wire? I mean cos there is only one not three. can you be more specific on how i check it, thanks. its sposed to warm up next week so ill hit the junkyard and work on the car and report back. i drive the car everyday, and i mean its not that big a deal, but the stalling when its cold and the hesitation are just annoying.

Are you talking about just checking the o2 sensor wire? I mean cos there is only one not three. can you be more specific on how i check it, thanks. but the stalling when its cold and the hesitation are just annoying.
For the wire itself. disconnect it at the sensor AND at the other end. All you want to be testing is the wire itself from end to end w/ the meter. Set your meter to resistance setting and that the leads are properly attached to your meter (some meters require you to change how it's setup to test for resistance physically). put one lead to the start of the wire and the other lead to the end of the wire. A high resistance or infinite resistance reading would indicate an open wire or a wire that has been cut off or near cutoff/pinched/overheated. What you want to see is near ZERO resistance, showing that current can flow continuously through the wire and there are no breaks in it or shorts. Next have one lead connected to the wire and the other to ground. If you show any continuity, it is shorting to ground and should be repaired (heat shrink over fixed connection) or replaced with a new wire of the SAME guage. Next, i would do both tests while wiggling the wire. If it shows nervousness or hunting, you got a problem with that wire(make sure you have a good lead connection to wire as you wiggle it around) I would NEXT (VERY IMPORTANT!!) visually check each inch of the wire for any signs of overheating, fraying, exposed wire, pinched wire, melting....if it is one wire, find the right guage replacement wire that matches it and replace w/ new. Important that the guage of wire is the same.

Since you have 3 trouble codes. The codes don't necessarily indicate a problem with the component itself, but rather the problem lies somewhere in the circuit (i.e. wiring) of the related component. So don't just test the component, check the wiring also. Because if the wiring is still bad, you might have wasted a new part when you turn on the switch.

I know this is dumb, but how tight are your battery connections?

BTW: When i meant check ALL three circuits, I meant checking each trouble code that your computer came up with. Not the (3) wires you meant for the 3100 engine like i have. So check off each code as you check them.

My car had 11 trouble codes showing! My problem was the short was fooling the computer that ALL these circuits were bad, which they were not. A short can confuse your electronic brain, that is why it is important to do a visual and testing of the wire itself. Replacing a part with new doesn't always solve the problem.

For now, i would follow zeroinfinity's instructions and test/inspect/repair stuff as he says. Just do it methodically and you'll get to the source.

Alright thanks fur explaining that, i get what your saying now. I'll do that next week its sposed to warm up right now its in the teens out i wish i had a heated garage! (or a garage u could fit a car in period :rofl: ). Grr i hate winter!!! though i just got sum used snow tires and this baby PLOWS through the snow now. a wire very well could be shorted, my battery connections are good. and i never buy new parts ne way i have 4 junkyards down the street frum me, and small sensors and stuff are "free" :rofl:

I found a maf sensor that looked brand new so i bought it and threw that on, along with a TPS. I got two tps's from the boneyard, the one I pulled off my car has like oval holes for the screw and a metal ring, so I guess its MOVEABLE?? I found two kinds in the junkyard, one moveable one and one fixed one. Whats the difference???? I threw the fixed one on right now. Test drove the car around the block, didnt have any hesitation but still stalled when cold, ill see how it drives tommorow when i go to work though. I also picked up a coolant sensor.

Im gonna put the coolant sensor on today, the car STILL stalls and has hesitation problems, like youll push the gas and itll be fine then once your within this "zone" on the pedal the car just falls on its face and stays that way till you press it more. anyway can ANYONE answer my question about the two different TPSs???