ok, i need some help now - Page 3

public · #31 05-16-2004, 07:16 PM

I think you may have found your problem. Check your wiring harness starting at the Throttle Possition Sensor plug and check it all the way back to the ECM/PCM. There is no reason the signal from the TPS should change without you moving the throttle. Unless this car has a throttle servo for the cruise control. It sound like the TPS is loosing ground. Again Good luck.

perna00 · #32 05-16-2004, 08:36 PM

it doesn't fluctuate that much. i have a digital readout that has about 20 bars that correspond with the throttle. it flashes between 1 and 2 depending on how much current is going through the car. if i have my stereo on, the bar will go to 1 when the bass hits and back to 2 when it stops. is that a major difference? i thought that might be that bulletin that merlin gave me saying how the idle was influanced by the generator. i guess that if the groung for the pcm/ecm is losing it's entire ground it would cause the idle to fluctuate? i also had to add a jumper wire with +12v to the camshaft positioning sensor cause it was only getting about +3v and was throwing a check engine code. any idea where i should start now? should i still get the ecm flashed? i do have the 96' ld9 automatic like it says.

GRANDAMLD9 · #33 05-17-2004, 02:40 AM

i have problems with my grand am along these lines. When i start my car and press the gas it hesitates and the car jerks. The car is also starting really ruff anymore and im throughing a P0420. do you think the problem in the bulleten is what is wrong with my car? how much would it cost at a dealer to fix this?

perna00 · #34 05-17-2004, 04:47 AM

that code (420) is because the catalitic converter is not working efficiant enough. i had that code about a year ago. it was about $350 for a new one from gm so i bought a high-flow one from summitracing.com for $50. after i installed it i never got the code again

GRANDAMLD9 · #35 05-17-2004, 05:14 PM

yea thats what i thought. but what could be causing my bogging problem. its strange b/c it does it randomly. after i start the car i will press on the gas and the car will bog down and harly move the car and sometimes i just give it a good rev to 3grand and its fine after that. could it be the same problem that was pointed out in the bulleten?

perna00 · #36 05-17-2004, 06:35 PM

that is the same problem as mine. Does yours have the unstable idle after it warms up too? the bulletin for the pcm reflashed says it just for the 96's w/ an automatic though. that's mine, but what about yours? i'm going to get mine flashed hopefully by the end of the week and i'll let you know if it corrects my problem. if not hopefully one of us will figure it out and let the other know. at least you can look back and see about 50 things that don't correct the problem that i've already tried! (said with what humor i've got left about the issue)

C_Sephiroth · #37 05-17-2004, 09:38 PM

You might have a problem with your coolent Temp Sensor. it will make your car run like that if it is reading the wrong temp (also if you have low coolant)

perna00 · #38 05-18-2004, 05:08 AM

mine has been replaced already. maybe it will work for grand

perna00 · #39 05-18-2004, 07:00 PM

$%@&! i just talked to the garage and found out when they reprogrammed my new ecm they already had all the updated materials in it when they reflashed it. anyone know the insurance payoff of a 96' cav. convertable? lol. any other advice?

nova racer · #40 05-19-2004, 07:03 AM

Quote:

Originally Posted by perna00

$%@&! i just talked to the garage and found out when they reprogrammed my new ecm they already had all the updated materials in it when they reflashed it. anyone know the insurance payoff of a 96' cav. convertable? lol. any other advice?

that is easy. suck some sea foam through a good vacume soece while the engine is running around 1,400 rpm and pour a bottle in the tank. then use the aout-rx in the engine oil (this stuff works wonders)http://www.auto-rx.com/

perna00 · #41 05-19-2004, 07:32 PM

found out some more info if it helps. i've noticed that when ever it is idling rough that maybe once every five seconds i hear a "click" noise somewhere in the top end of the engine. it's not patterned. any new advice?

Shady2001 · #42 05-24-2004, 11:30 AM

My 97 Sunfire GT was doing the same thing and all i did was put greased lightning fuel treatment in and put new fuel infectors in and it ran fine.

perna00 · #43 05-24-2004, 12:02 PM

would yours act up only sometimes? i inverted my fuel rail w/ the injectors and they all seemed to spray fine and even

strange_trp · #44 11-21-2004, 05:13 PM

so rough idle, hard start... low surging idle... i think i read that you only have idle problems and hesitation when first accelerating, and it runs fine at higher engine speeds...
my first thought would be vac leak or egr sticking open, maybe clogged passage holding pintle off seat.
if you have access to scan tool, check out your long term trim... also check MAP voltage and look at MAF readings at idle and at 2k rpm...
if LT trim is going rich, suspect vac leak... if LT trim is going lean, suspect leaking EGR. you may want to put a scope on your ckp and cmp sensors. should be regular clean waveform. i believe yours has a hall effect cmp and a magnetic reluctor type ckp (but i may be wrong... don't have alldata in front of me now...) hall effect should be pretty square wave, sharp sqare corners on leading and falling edge.
also ck input voltage to MAP. should be batt (+) volts.
as always, ck voltage drop of sensor grounds, especially MAP and MAF. on the 96, the pcm uses maf to calculate load and map to check egr operation (generally)... voltage drop of ANY sensor gnd ckt should be < 100mvDC. disconnect batt, disconnect pcm connectors, ck for short to gnd on egr ctrl ckt... granted, this should set code on OBD-II veh, but i've seen stranger things.

strange_trp · #45 11-21-2004, 05:15 PM

so rough idle, hard start... low surging idle... i think i read that you only have idle problems and hesitation when first accelerating, and engine runs fine at higher rpms...
my first thought would be vac leak or egr sticking open, maybe clogged passage holding pintle off seat.
if you have access to scan tool, check out your long term trim... also check MAP voltage and look at MAF readings at idle and at 2k rpm...
if LT trim is going rich, suspect vac leak... if LT trim is going lean, suspect leaking EGR. you may want to put a scope on your ckp and cmp sensors. should be regular clean waveform. i believe yours has a hall effect cmp and a magnetic reluctor type ckp (but i may be wrong... don't have alldata in front of me now...) hall effect should be pretty square wave, sharp sqare corners on leading and falling edge.
also ck input voltage to MAF (correction from prev post... 5+ to MAP, 12+ to MAF).
as always, ck voltage drop of sensor grounds, especially MAP and MAF. on the 96, the pcm uses maf to calculate load and map to check egr operation (generally)... voltage drop of ANY sensor gnd ckt should be < 100mvDC. disconnect batt, disconnect pcm connectors, ck for short to gnd on egr ctrl ckt... granted, this should set code on OBD-II veh, but i've seen stranger things.

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