ok, i need some help now

[losingxposer]

i have to agree with the Throttle Position Senser...it did it on mine too...acts like when you give it the gas just a tad to much it wants to cut off..then when you easily get on it...it works fine...also..you might want to check and see if it needs positioning correctly...that can do it to.

[perna00]

k, i replaced the throttle position sensor. NO LUCK!!!! I'm getting tired of this problem.

alright, here's the summary. anyone can correctly tell me what the $#%& is wrong with my car will get a $20 mailed out to them. i'm stuck.

here's the problems: when i start up the car it will hesitate majorly and miss for the first minute and a half then after that it will idle rough when stopped. then if you hit the gas quickly it will hesitate for only a sec. i have lost horsepower. occasionally a "random multiple cylinder misfire" code
so far in the last 2 years i have replaced the: spark plugs, boots, coil housing, fuel pump, fuel filter, throttle positioning sensor, map sensor, extire exhaust, both o2 sensors, extire intake system, new collant temperature sensor.

[losingxposer]

Have you thought about maybe the head gasket is blown?...because mine did that and come to find out after i checked the oil there was water in it...just an idea.

[equalizr]

A head gasget would cause all these problems? how easy are/is to replace?

If its an easy cheap way, i should do it to mine as well..i have one of those Hayne's manuals that shows you how to do everything

[perna00]

i've checked my oil and there is no antifreeze mixed in at all. i'm about to get the tools and test the ohms of the injectors and coils like mentioned earlier and if that don't help i'm going to test the fuel pressure and vacuum pressure.

[GMMerlin]

Originally Posted by perna00

k, i replaced the throttle position sensor. NO LUCK!!!! I'm getting tired of this problem.

alright, here's the summary. anyone can correctly tell me what the $#%& is wrong with my car will get a $20 mailed out to them. i'm stuck.

here's the problems: when i start up the car it will hesitate majorly and miss for the first minute and a half then after that it will idle rough when stopped. then if you hit the gas quickly it will hesitate for only a sec. i have lost horsepower. occasionally a "random multiple cylinder misfire" code
so far in the last 2 years i have replaced the: spark plugs, boots, coil housing, fuel pump, fuel filter, throttle positioning sensor, map sensor, extire exhaust, both o2 sensors, extire intake system, new collant temperature sensor.

OK
First I would check the coils and coil cover..make sure 1-4 aren't shorted to 2-3
Next I would check injectors..mostly an injector balance test to make sure that all injectors are dropping the same amount of fuel..a fuel pressure gage and an injector tester are needed for that.
Fuel sample..is there any water in the fuel?

Here are a couple of GM technical bulletins that may apply..the first one I have seen cause what you are describing.
ENGINE STALL AT COLD START, ROUGH IDLE, OIL FILTER #77-61-09B - (11/07/1997)
REVISION: 05/08/97

THIS BULLETIN IS BEING REVISED TO ADD CHEVROLET MALIBU TO MODELS. PLEASE DISCARD CORPORATE BULLETIN 77-61-09 (SECTION 6--ENGINE). __________________________________________________ ____________________

REVISION: 10/16/97

THIS BULLETIN IS BEING REVISED TO ADD A NEW SERVICE PROCEDURE AND TO REVISE THE SERVICE PARTS INFORMATION. PLEASE DISCARD CORPORATE BULLETIN 77-61-09A (SECTION 6--ENGINE). __________________________________________________ ____________________

SUBJECT: ENGINE STALL AT COLD START, ROUGH IDLE, OIL FILTER EXPANSION, HIGH OIL PRESSURE, AND P0300 DTCS (REPLACE OIL PUMP COVER ASSEMBLY)

MODELS: 1995-97 BUICK SKYLARK 1995-97 CHEVROLET CAVALIER 1997 CHEVROLET MALIBU 1995-97 OLDSMOBILE ACHIEVA 1995-97 PONTIAC SUNFIRE, GRAND AM 1996-97 TOYOTA CAVALIER WITH 2.3L, 2.4L ENGINE (VINS D, T - RPOS LD2, LD9)

CONDITION:

SOME VEHICLES MAY EXHIBIT ONE OF A NUMBER OF CONCERNS RELATED TO THIS CONDITION. THE MOST COMMON SYMPTOM WILL BE STALLING ON INITIAL COLD STARTING, FOLLOWED BY HARD RESTARTING. OTHER CONCERNS MAY INCLUDE OIL FILTER CANISTER EXPANSION OR LEAKAGE AND HIGH OIL PRESSURE WHEN CHECKED WITH A GAUGE. SOME VEHICLES MAY ALSO EXHIBIT DIAGNOSTIC TROUBLE CODES P0300, P0301, P0302, P0303, AND P0304 INDICATING ENGINE MISFIRE CONDITIONS. OIL PRESSURE AT OPERATING TEMPERATURE MAY EXCEED 827 KPA (120 PSI).

CAUSE:

DUE TO A CONDITION OF THE RELIEF VALVE AND THE RELIEF VALVE BORE, THE RELIEF VALVE MAY INTERMITTENTLY BECOME STUCK CAUSING HIGH OIL PRESSURE. THE INCREASED OIL PRESSURE MAY CAUSE THE HYDRAULIC VALVE LIFTERS TO RAISE THE VALVES OFF OF THEIR SEATS CREATING A LOSS OF COMPRESSION AND ENGINE MISFIRE OR STALLING ON INITIAL STARTUP.

DIAGNOSIS:

IF THE VEHICLE EXHIBITS ANY OF THE ABOVE CONDITIONS, INSTALL AN OIL PRESSURE GAUGE CALIBRATED TO READ AT LEAST 1034 KPA (150 PSI) IN THE OIL PRESSURE PORT ON THE INTAKE CAMSHAFT CARRIER AND OBSERVE OIL PRESSURE AT 3000 RPM. THE OIL PRESSURE, EVEN IN EXTREME COLD, SHOULD NOT EXCEED 689 KPA (100 PSI). WITH THE ENGINE OIL AT OPERATING TEMPERATURE, OIL PRESSURE SHOULD NOT EXCEED 586 KPA (85 PSI). AT 3000 RPM.

CORRECTION:

IF THE OIL PRESSURE EXCEEDS THESE LIMITS, REPLACE THE OIL PUMP COVER WITH AN OIL PUMP COVER THAT HAS AN IMPROVED PRESSURE RELIEF VALVE AND PRESSURE RELIEF VALVE BORE.

SERVICE PROCEDURE 1. REMOVE THE RADIATOR OUTLET PIPE AND THE ENGINE OIL PAN, USING PROCEDURES OUTLINED IN SECTION 6A7 OR THE ENGINE MECHANICAL SECTION OF THE APPROPRIATE SERVICE MANUAL.

2. REMOVE THE BALANCE SHAFT DRIVE CHAIN COVER.

3. REMOVE THE BALANCE SHAFT DRIVE CHAIN TENSIONER SHOE.

IMPORTANT: DO NOT REMOVE THE BALANCE SHAFT DRIVE CHAIN OR BALANCE SHAFT DRIVE SPROCKET.

4. REMOVE ONLY THE OIL PUMP COVER ASSEMBLY.

5. INSTALL THE NEW OIL PUMP COVER ASSEMBLY GM P/N 24577081.

6. TIGHTEN THE FOUR LONG BOLTS TO 12 NM (106 LB IN).

7. TIGHTEN THE SHORT BOLT TO 10 NM (89 LB IN).

8. INSTALL THE BALANCE SHAFT DRIVE CHAIN TENSIONER SHOE AND THE BALANCE SHAFT DRIVE CHAIN COVER USING PROCEDURES OUTLINED IN SECTION 6A7 OR THE ENGINE MECHANICAL SECTION OF THE APPROPRIATE SERVICE MANUAL.

IMPORTANT: DO NOT USE EXCESSIVE PRESSURE WHEN INSTALLING THE BALANCE SHAFT DRIVE CHAIN TENSIONER. EXCESSIVE BALANCE SHAFT DRIVE CHAIN TENSION WILL RESULT IN NOISE AND WEAR CONCERNS.

9. REINSTALL THE ENGINE OIL PAN AND THE RADIATOR OUTLET PIPE, REFER TO SECTION 6A7 OR THE ENGINE MECHANICAL SECTION OF THE APPROPRIATE SERVICE MANUAL.

PARTS INFORMATION:

WHENEVER ORDERING PARTS, REFER TO THE FOLLOWING PART NUMBER: DESCRIPTION COVER ASSEMBLY, ENGINE OIL PUMP GM PART NUMBER 24577081


GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER". THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS THAT MAY OCCUR ON SOME VEHICLES, OR TO PROVIDE INFORMATION THAT COULD ASSIST IN THE PROPER SERVICE OF A VEHICLE. PROPERLY TRAINED TECHNICIANS HAVE THE EQUIPMENT, TOOLS, SAFETY INSTRUCTIONS AND KNOW-HOW TO DO A JOB PROPERLY AND SAFELY. IF A CONDITION IS DESCRIBED, DO NOT ASSUME THAT THE BULLETIN APPLIES TO YOUR VEHICLE, OR THAT YOUR VEHICLE WILL HAVE THAT CONDITION. SEE A GENERAL MOTORS DEALER SERVICING YOUR BRAND OF GENERAL MOTORS VEHICLE FOR INFORMATION ON WHETHER YOUR VEHICLE MAY BENEFIT FROM THE INFORMATION.

COPYRIGHT 1997. GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.



GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION


© Copyright General Motors Corporation. All Rights Reserved.

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IDLE FLUCTUATION IN GEAR OR RPM HUNTING #67-65-29 - (08/20/1996)
SUBJECT: IDLE FLUCTUATION IN GEAR OR RPM HUNTING DURING DECELERATION AND UNSTABLE IDLE (FLASH CALIBRATION)

MODELS: 1996 CHEVROLET CAVALIER 1996 PONTIAC SUNFIRE WITH 2.4L ENGINE (VIN T - RPO LD9) AND AUTOMATIC TRANSMISSION ONLY

CONDITION:

SOME OWNERS MAY EXPERIENCE AN IDLE FLUCTUATION IN DRIVE OR RPM "HUNTING" DURING DECELERATION AFTER REACHING NORMAL OPERATING TEMPERATURE.

CAUSE:

THE PCM CONTROLLED CLOSED LOOP IDLE SYSTEM MAY BE INTERACTING WITH THE GENERATOR LOAD, RESULTING IN CORRECTIONS THAT APPEAR AS IDLE SPEED FLUCTUATIONS.

CORRECTION:

A NEW CALIBRATION HAS BEEN DEVELOPED TO STABILIZE THE IDLE SPEED. THIS CALIBRATION SHOULD ONLY BE INSTALLED IF THE OWNER HAS INDICATED A CONCERN WITH THE VEHICLE IDLE STABILITY OR IDLE SPEEDS.

PERFORM THE PCM FLASH CALIBRATION PROCEDURE USING THE NUMBER 14 CD-ROM UPDATE OR LATER VERSION. CORRECT CALIBRATION INFORMATION IS LISTED IN THE CHART BELOW.

PARTS INFORMATION

APPLICATIONS/ BROADCAST PART NUMBER AND EMISSIONS CODE SCAN ID

FEDERAL BZAZ 16249193 CALIFORNIA BZBA 16249203 EXPORT BZAY 16249183

[perna00]

ok everyone, i just finished a compression test. they all reached there maximum psi with normal incraments. the maximum psi value's are 185, 195, 200, and 205. i know that if the compression values are too high i have too much carbon build up in the cyclinder chamber, but i don't know if my values are considered "high". any experts on the subject?

[public]

Those compression numbers don't look too bad. So your head gasket is good. I guess I would check the items mentioned in the above Tech Service Bulletin.

[perna00]

more results. the ohms on the coils are .7ohms. the ohms on the injectors are: 2.3, 2.5, 2.5, 2.5. the coil housing has no shorts

[perna00]

thanks alot merlin and public for the latest info. so merlin, just how hard is it to change the oil pump cover? i've done more than my share of engine work and was wondering if there is any special concers with changing it. should i also replace the oil pump since i've gotten that far? also, how would i get my pcm flashed with the new info and how much would it cost (ballpark)

[public]

Usually you can buy a oil pump in a stock and high volume versions. Not too expensive. About $50 as for replacement I have not done one on this car, but they are not usually too bad.

[perna00]

so i take it i should probably get the high volume pump? also merlin, could i use an oil pressure test to check to see if it rules out the 1st service bulletin you posted?

[GMMerlin]

Originally Posted by perna00

so i take it i should probably get the high volume pump? also merlin, could i use an oil pressure test to check to see if it rules out the 1st service bulletin you posted?

Thats what the bulletin states
DIAGNOSIS:

IF THE VEHICLE EXHIBITS ANY OF THE ABOVE CONDITIONS, INSTALL AN OIL PRESSURE GAUGE CALIBRATED TO READ AT LEAST 1034 KPA (150 PSI) IN THE OIL PRESSURE PORT ON THE INTAKE CAMSHAFT CARRIER AND OBSERVE OIL PRESSURE AT 3000 RPM. THE OIL PRESSURE, EVEN IN EXTREME COLD, SHOULD NOT EXCEED 689 KPA (100 PSI). WITH THE ENGINE OIL AT OPERATING TEMPERATURE, OIL PRESSURE SHOULD NOT EXCEED 586 KPA (85 PSI). AT 3000 RPM

[GMMerlin]

Originally Posted by perna00

thanks alot merlin and public for the latest info. so merlin, just how hard is it to change the oil pump cover? i've done more than my share of engine work and was wondering if there is any special concers with changing it. should i also replace the oil pump since i've gotten that far? also, how would i get my pcm flashed with the new info and how much would it cost (ballpark)

depending on the dealer, less than $100 for a calibration update

Document ID# 61551
1996 Chevrolet/Geo Cavalier

--------------------------------------------------------------------------------

Oil Pump Replacement
Removal Procedure
Disconnect the negative battery cable. Refer to

Caution
Before servicing any electrical component, the ignition key must be in the OFF or LOCK position and all electrical loads must be OFF, unless instructed otherwise in these procedures. If a tool or equipment could easily come in contact with a live exposed electrical terminal, also disconnect the negative battery cable. Failure to follow these precautions may cause personal injury and/or damage to the vehicle or its components.


in General Information.
Remove the engine oil pan. Refer to Oil Pan Replacement .



Remove the balance shaft chain cover.



Remove the balance shaft chain tensioner assembly.
Remove the oil pump cover.
Remove the oil pump.
Installation Procedure
Install the oil pump



Install the oil pump cover to balance shaft housing.

Notice
Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.


Tighten
Tighten the pump to housing long bolts to 12 N·m (2.69 lb in).
Tighten the pump to housing short bolts to 10 N·m (2.24 lb in).




Install the balance shaft chain tensioner.

Important
A brass feeler gauge needs to be used to ensure correct measurements are obtained. If a steel gauge is used, it will not bend to conform to the guide and will not allow for correct measurements.


Adjust the balance shaft drive chain tension by inserting a 1 mm (0.040 in). Brass feeler gauge between the chain guide and the chain.
Press the guide against the chain using about 3 pounds of force.
Tighten the chain tensioner. Tighten
Tighten the bolt to 13 N·m (115 lb in).

Install the oil pan gasket and the oil pan. Refer to Oil Pan Replacement .
Connect the negative battery cable.

[perna00]

merlin, i just did a compression test on the oil pressure. it was around 100psi @ 3000rpms upon startup. after it ran for a minute (but not to operating temperature) it started idling rough and the pressure gauge still read around 100psi so i know it's not from high oil pressure holding the valves. i reread your bulletin about the generator load affecting the idle and did notice that when ever my idle loops, so does the digital readout of the throttle positioning sensor. it idles up as the signal increases and idles down as the signal decreases. i think that i might just need my pcm flashed like it says. will that cause a loss of horsepower just from the wrong data how my car is running now?