My engine check light is on,
i have a 98 sf gt 5 speed and im finding that at 25 to 3k my cars rpms will drop for a second during acceleration. it idle's fine. i also fined that my cruise control will not work when the light is on. i have put in 91 octane didnt change, the gas cap is tight. i know it has something to do with imissions. my dad was in a accident with it,the driveshaft needed to be changed, hub, suspetion etc. the water pump also "went " while at the dealer.It also does this when the lights off (when its off) any ideas would be much much appreciated.



maybe not today, maybe not tomorrow....... but some day

if the engine light is on i assume you had the codes read already right?.....right?

what codes are in the system ?

im sorry my comp went in cause its also messed. ok to the car the codes where the crank sensor, cam sensor, and the 02. i got the dealership to do the crank sensor, and i did the 02 sensor last night?and fuel filter tonight. the car is still the same WTF? the check engine light is still on. i now know it has nothing to do with the velosity joint or tranny. the car has been like this for a month. im now ready to change the cam sensor but i dont know what it looks like or where to find it.? i have another appoint on tues. this is pissing me off. any help is appreciated and i will respond.



maybe not today, maybe not tomorrow....... but some day

The cam sensor is probably near the cam. It should look just like a crankshaft position sensor.

Not sure on what is wrong, maybe the mass air flow sensor, or throttle body, whatever they use? Maybe it's something in the air intake system, or the throttle position sensor.



1983 Camaro Z28

good call lolo, but i dont know what the crank position sensor looks like? anybody else?



maybe not today, maybe not tomorrow....... but some day

Hhmm... I don't know how to explain it. It has a wire that plugs into it, and it should be round.



1983 Camaro Z28

anybody else ^^ note sarcasm lol



maybe not today, maybe not tomorrow....... but some day

It's on the drivers side of the engine bay pretty much right under the connector for the ignition computer. ITs round and is sticking outta the intake cam housing. What were the exact codes you got? If they said something about the circuit or low input, it is probably not the sensor, but a wiring problem or something else. Also, what o2 sensor did u get?

my car is still at the dealer i forget the code #s, my appointment was today... and today they say that it is my icm (ignition control module) and there not 100% sure, if its not it supposed to be the pcm ? am i getting it in the ear? do these dealers not have the proper computer to scan the car and tell you whats wrong, or is it like a cheap model where theres 5 diff possibilities? i cannot afford them to do it. it feels like trial and error and i keep paying and paying. another dumb Q where is the icm? also the pcm is the main comp right? i dont know please help. i will have all the codes tommorow.

thank you



maybe not today, maybe not tomorrow....... but some day

here are a FEW of the things it could be

Definition: Momentary lack of response as the accelerator is pushed down. Can occur at any vehicle speed. Usually more pronounced when first trying to make the vehicle move, as from a stop sign. May cause the engine to stall if severe enough.

Preliminary


* Refer to the Powertrain On Board Diagnostic (OBD) System Check .
* Refer to Symptoms .

Sensor/System


* Check the EGR valve for a stuck open pintle.
* Check for proper operation of the MAP Sensor. Refer to Manifold Absolute Pressure (MAP) Sensor Output Diagnosis .
* Check for proper operation of the TP sensor.
* Check for proper operation of the ECT sensor.
* Check the Oxygen sensor (O2S 1). The O2S 1 should respond quickly to different throttle positions. If not, check the O2S 1 for silicon or other contaminants from fuel or the use of improper RTV sealant. The sensor may have a white powdery coating. Silicon contamination causes a high but false O2S 1 signal voltage (rich exhaust indication). The PCM will reduce the amount of fuel delivered to the engine, causing a severe driveability problem. Refer to Oxygen sensor in Information Sensors/Switches Description .

Fuel System


* Check the fuel pressure. Refer to Fuel System Diagnosis .
* Check for contaminated fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
* Check the fuel injectors. Refer to Fuel Injector Balance Test (SFI) .
* Check items which can cause an engine to run rich (long term fuel trim is significantly in the negative range). Refer to Diagnostic Aids for DTC P0172 Fuel Trim System Rich .
* Check items that can cause an engine to run lean (long term fuel trim is significantly in the positive range). Refer to Diagnostic Aids for DTC P0171 Fuel Trim System Lean .
* Check for proper operation of the Evaporative Emission (EVAP) control system. Refer to Evaporative Emission (EVAP) Control System Diagnosis .

Ignition System


* Check for proper ignition voltage output with the J 36012-A spark plug jumper wires and J 26792 spark tester or equivalent.
* Check the spark plugs for the following conditions:
o Check for wet or fuel fouled spark plugs.
o Check for cracks on the spark plugs.
o Check for wear.
o Check for improper spark plug gap.
o Check for burned electrodes or heavy deposits.
* If the spark plugs are fuel or oil fouled, the cause of the fouling must be determined before replacing the spark plugs.
* Check the Ignition Control Module (ICM) for proper ground connection.
* Check the ignition coils for cracks or carbon tracking.

Additional Checks


* Check for proper operation of the Automatic Transaxle. Refer to Functional Test Procedure in Automatic Transaxle.
* Check the generator output voltage. Repair the generator if the output voltage is less than 11 volts or more than 16 volts.
* If all procedures have been completed and no malfunctions have not been found, review and inspect the following items:
o Visually and physically inspect all electrical connections within the suspected circuit and/or systems.
o Check scan tool data.

Document ID# 401913

if you get teh trouble codes I can look up more 4 u

i've had a rough week im sorry i couldnt respond sooner.

"on aug 31st, we found P0138, P0335, and P0341, requires rear 02 sensor and crankshaft position sensor.may need cam position sensor but service info says replace crank sensor and road test before changing cam sensor"

these are the exact words on the gm repair sheet

sept 8th
changed crank pos. sensor.

sept 14th
"ses light back on and back fires. cust change rear 02 sensor and fuel filter."
" scan for codes, found P0335 and P0341check wires, check diagnostic tree, if both codes set replace crank pos. sensor. already done.next step replace ICM".

i changed that myself, now the sheet the mech gave me from service.gm.com says change PCM. which is in the open b/c my mom went to the store and busted the plastic wheel opening . now the 02 sensor that i replaced was behind the catalatyc conv. but still went to the front of the car, i just wasnt sure if that was a 'rear 02 sensor or not'.
i still have not replaced the cam sensor b/c the gm service site says to do the above first. and where is the cam sensor?

sorry for the long post but anything would help. hope those # mean somthing to ya Cinny.



maybe not today, maybe not tomorrow....... but some day

Circuit Description

The electronic ignition control module (ICM) sends a reference signal to the powertrain control module (PCM). The ICM sends this signal 7 times per crankshaft revolution in order to indicate the crankshaft position and the RPM. This enables the PCM to determine when to pulse the ignition coils and control the ignition timing. This signal is called the medium resolution or 7X reference. The ICM applies 5 volts through the 7X reference circuit to the PCM. This, in effect, switches this circuit to ground for a very short period of time. The seventh pulse is the sync pulse and is used for crankshaft position reference.
Conditions For Setting The DTC

* The 7X resync counter goes greater than 15 within 4 minutes and 15 seconds.
* DTC P0341 not set.

Action Taken When the DTC Sets

* The malfunction indicator lamp (MIL) illuminates.
* The PCM records the operating conditions at the time when the diagnostic fails. This information stores in the Freeze Frame and Failure Records buffers.
* A history DTC stores.
* The coolant fan turns ON.

Conditions for Clearing the MIL/DTC

* The MIL will turn OFF after three consecutive ignition cycles in which the diagnostic runs without a fault.
* A history DTC will clear after 40 consecutive warm-up cycles without a fault.
* The MIL/DTCs can be cleared by using the scan tool.

Diagnostic Aids

* If the complaint was Cranks But Will Not Run, you may set a DTC P0335 when attempting to start the engine more than 15 times and the ignition is not turned OFF between attempts.
* An intermittent problem may be caused by the following conditions:
o Rubbed through wire insulation
o Poor electrical connection
o Broken wire inside of the insulation
* Thoroughly check any suspected circuitry for the following conditions:
o Backed out terminals
o Improper mating
o Broken locks
o Improperly formed
o Damaged terminals
o Poor terminal to wiring connections
o Physical damage to the wiring harness
* An intermittent can also be the result of a defective reluctor wheel. Remove the crankshaft sensor and inspect the reluctor wheel through the hole. Check for the porosity and the condition of the wheel. Refer to Crankshaft Balancer Clean and Inspect .

Test Description

The numbers below refer to the step numbers on the Diagnostic Table.

1. The Powertrain OBD System Check prompts you to complete some of the basic checks and to store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data captured when the malfunction occurred. The scan tool stores this data for later reference.
3. This step determines if the PCM recognizes a problem. If the DTC does not reset at this point, the problem may be intermittent.
4. When a Medium Resolution Resync occurs, engine stumble should also occur. If a component electrical connection or an electrical wire is malfunctioning, an engine stumble or a medium resolution resync may be induced by wiggling the circuit or electrical connector.
5. Operating malfunctioning non-engine related electronic components may emit Electromagnetic Interference (EMI) which may cause a resync. This step will determine if the medium resolution resync(s) are being caused by an outside source.
6. Thoroughly check any suspected circuitry for the following conditions:
* Backed out terminals
* Improper mating
* Broken locks
* Improperly formed or damaged terminals
* Poor terminal to wiring connections
* Physical damage to the wiring harness
8. An intermittent problem may be caused by the following conditions:
* Rubbed through wire insulation
* Poor electrical connection
* Broken wire in the insulation
12
Program the replacement PCM and perform the crankshaft position system variation learn procedure. Refer to PCM Replacement/Programming for PCM reprogramming and refer to CKP System Variation Learn Procedure for the Crankshaft Position System Variation Learn Procedure.

==================================================================

just a thought

break loose, clean and reconnect all the grounds you can find, use a contact cleaner to do it (spray can), not a wire brush etc, reason being it you will scrape the coating off of the area and it may corrode worse than it was.


had something else too but its slipped my mind at the moment...grr

if you have a 2.4 this is where the part is .. hope this helps

wtf?! that's the camshaft sensor? I always thought it was the sensor like right under the icm, connected right to the intake cam housing. which one is that?

97redgt hey not sure which one you are talking about .. is it in this pic ??

yea, that's the one

I hope this helps you out .. good luck

haha, awesome, thanks

thank you robert and cinny, i repaced the icm already and im going to do the pcm tomorrow, and if its still messed up i will do the cam sensor. thank you, thank you, thank you for all your help, all these parts i have bought are all returnable for a full refund. i will keep you posted thanks again for the pics.



maybe not today, maybe not tomorrow....... but some day

Ironicly, some of the syptoms are what my 98 Sunfire GT is getting these days, but no CEL at all, my dad thinks it could be a couple of things, like a vacumm leak, or even my back brakes not seating right, which i disproved, because my parking brake doesnt even engage unless the handle is all the way up. My car feels like its lost its low end power at low rpm, and almost stalled 3rd at 20, and normally it runs fine. Im gonna investigate the car tomorrow and see what i can come up with.

ok her is another Q do you have to reprogram the pcm before you put it in? i put one in and the car ran for a second and then shut off, my theft light was flashing? .. ...................................................................so i put the old pcm in. anymore help is very much appreciated.



maybe not today, maybe not tomorrow....... but some day

yup take it to the dealer and have them flash it for you, you'll need your VIN I'm sure, almost have to have the thing to go to the bathroom there.

the pcm is from a 99 2.2 3 sp auto that shouldnt make a diff right? thanx cinny i will keep you posted.



maybe not today, maybe not tomorrow....... but some day

is there any diff.?



maybe not today, maybe not tomorrow....... but some day