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Old 01-05-2008   #21
yves_transam
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Re: TPI problem

Quote:
Originally Posted by FearThisGTA
Somehow or another I am not quite understanding what exactly your wanting to know or waht your problem is?
my car start very well but no power when i drive it...
it doesn't run strong...

As if the th 700 r4 was out of order (it's new...so it cannot be that).

no ses light no trouble code...so there's something wrong...
I want to know what is malfunctionning et how to check and repair it...

I know that my engine doesnt give all of the power...

isn't clear?

another example :
when I start my car...the rpm should be to four levels (1000 rpm) and after slowly down to three levels (near 500...it's a digit)...

In fact whan I start it...it's on 600 after 5 second go to 800 and down when hot (50 degrees) to 500...that's not the right way...

It's clear or not?
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Old 01-05-2008   #22
MunsonGTA
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Re: TPI problem

Quote:
Originally Posted by FearThisGTA
Somehow or another I am not quite understanding what exactly your wanting to know or waht your problem is?
i think what he's basically saying is that he has a lack of power in the car, and that it's having hot start issues as if the starter is getting heat soaked.
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87 GTA: Forged 408 LSX short block, TEA stage 2 cnc ported 243 heads, BTR Stage 3 stroker cam, Fast 102 intake, NW 102 TB, Longtube headers, custom 411 ECM, custom harness, custom tuned, Performabuilt stage 2 4l60E with PTC 2800 stall, 9 bolt rear with 3.70 gears and TAP girdle.

11.16 at 123 mph.
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Old 01-05-2008   #23
MunsonGTA
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Re: TPI problem

Quote:
Originally Posted by yves_transam
Thanks GUYS....

In fact I knew my car with a strong power...so I'm sure...there's a problem about electronic or vacum leak...

How can we check a vacum leak and on what part must I verify it...
PIcs are welcome cause I'm not strong in cheking engine...
my engine is a 88 350
ecm new/O2 new.../spaks plug new...no SES error
to check for vacuum leaks, you need either a vacuum gauge or a can of starting fluid. if you can get a gauge, you can plug it into the vacuum system (the rubber air lines) and see what kind of a reading you get. if you just want to use the starting fluid, try to spray a mist around your vacuum line connections and listen for the idle of the motor to change. if you spray it and the idle raises, you have a leak.
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87 GTA: Forged 408 LSX short block, TEA stage 2 cnc ported 243 heads, BTR Stage 3 stroker cam, Fast 102 intake, NW 102 TB, Longtube headers, custom 411 ECM, custom harness, custom tuned, Performabuilt stage 2 4l60E with PTC 2800 stall, 9 bolt rear with 3.70 gears and TAP girdle.

11.16 at 123 mph.
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Old 01-05-2008   #24
MunsonGTA
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Re: TPI problem

Quote:
Originally Posted by yves_transam
my car start very well but no power when i drive it...
it doesn't run strong...

As if the th 700 r4 was out of order (it's new...so it cannot be that).

no ses light no trouble code...so there's something wrong...
I want to know what is malfunctionning et how to check and repair it...

I know that my engine doesnt give all of the power...

isn't clear?

another example :
when I start my car...the rpm should be to four levels (1000 rpm) and after slowly down to three levels (near 500...it's a digit)...

In fact whan I start it...it's on 600 after 5 second go to 800 and down when hot (50 degrees) to 500...that's not the right way...

It's clear or not?
]

the idle issue sounds like either your TPS isn't adjusted correctly, or you could possibly need a new IAC, or it might need cleaned. IAC is idle air controller, and it's located under the throttle body and has a 4 wire plug going to it. the plug should be grey color.
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87 GTA: Forged 408 LSX short block, TEA stage 2 cnc ported 243 heads, BTR Stage 3 stroker cam, Fast 102 intake, NW 102 TB, Longtube headers, custom 411 ECM, custom harness, custom tuned, Performabuilt stage 2 4l60E with PTC 2800 stall, 9 bolt rear with 3.70 gears and TAP girdle.

11.16 at 123 mph.
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Old 01-06-2008   #25
FearThisGTA
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Re: TPI problem

I agree with Munson, but also on the lack of power, check your timing.hth
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Old 01-06-2008   #26
yves_transam
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Re: TPI problem

Quote:
Originally Posted by MunsonGTA
]

the idle issue sounds like either your TPS isn't adjusted correctly, or you could possibly need a new IAC, or it might need cleaned. IAC is idle air controller, and it's located under the throttle body and has a 4 wire plug going to it. the plug should be grey color.
thanks guys...

So I'm gonna try to explain it to you...

Three years ago...My car had the same symptoms...lack of power bad start when hot...bad rpm speed level change

that time, It was just the TPS value...

now the same problem but impossible to find it...

So for the iac how to check it....and a strange thing is why the ecm doesn't light...

For the vacum leak..will test it next week and let you know...
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Old 01-14-2008   #27
yves_transam
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Re: TPI problem

I took a look at the iac valve...it's not very clean...all black...
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Old 01-14-2008   #28
MunsonGTA
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Re: TPI problem

i would try to clean it with some carb cleaner.
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87 GTA: Forged 408 LSX short block, TEA stage 2 cnc ported 243 heads, BTR Stage 3 stroker cam, Fast 102 intake, NW 102 TB, Longtube headers, custom 411 ECM, custom harness, custom tuned, Performabuilt stage 2 4l60E with PTC 2800 stall, 9 bolt rear with 3.70 gears and TAP girdle.

11.16 at 123 mph.
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Old 01-19-2008   #29
yves_transam
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Re: TPI problem

Quote:
Originally Posted by MunsonGTA
i would try to clean it with some carb cleaner.
Hello here is a pic f my tps...it's not easy to see but it seems to too up...

ahhhrgh to pic beacause too loud...how can I post it?
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Old 01-19-2008   #30
yves_transam
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Re: TPI problem

Quote:
Originally Posted by yves_transam
Hello here is a pic f my tps...it's not easy to see but it seems to too up...

ahhhrgh to pic beacause too loud...how can I post it?
So now I've found something new...

I tried to make the test of iac...with a pin in the aldl and the iac disconnected...
So first my car did'n't start..I tried two times...after a while I did it again and the car start but with a very low idle...

So As the test explained...I screw the IAC screw on the throttle...that up my idle...now the screw is at the maximum...(I'm not sure it's good

After I saw the TPS that was very high...and I could pull at 0.55...v

now the car run better but not at the right power...
I'm sure I got something that's not nice ....

So the temp is not good..the car run at 50 70 degrees celcius..it must be at 90 degrees

The better : more power over 2500 rpm...
under 2500 the speed isn't good and when I accelerate it change the gear....

what could be unsettled and have influence on the idle and power???

The temp sensor maybe or something else...?

what is to settle except the tps and IAC...thanks a lot...

I wish you understood what I wanna tell..
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Old 01-19-2008   #31
yves_transam
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Re: TPI problem

just a precision..my th 700 has been changed..maybe something would have to be settle...?no?

hre is the pic of my tps before I screwed the iac
Attached Images
File Type: jpg IMAGE_046.jpg (54.0 KB, 8 views)
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Old 01-19-2008   #32
gtayumiko
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Re: TPI problem

Quote:
Originally Posted by MunsonGTA
i would try to clean it with some carb cleaner.
Be careful when using carburator cleaner on sensors, it will ruin most sensors. Maybe it could be fine to use it on mechanical stuff to clean it, but do not use it on sensors that have a special coating on them because the cleaner will damage the special coatings.
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Old 01-19-2008   #33
gtayumiko
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Re: TPI problem

Quote:
Originally Posted by yves_transam
just a precision..my th 700 has been changed..maybe something would have to be settle...?no?

hre is the pic of my tps before I screwed the iac
That is not the IAC. That is the TPS (Throttle Position Sensor) and the TPS is very difficult to adjust properly. You need to use a voltmeter to adjust it properly.

But another thing to consider is if your engine is running fine but you have no power, that happened to my GTA twice before, once was a collapsed muffler and the second time was a chunk of the cat. converter broke off and got lodged in the exhaust pipe where it goes up at the differentials. If your car has a serious exhaust blockage, your car will not shift automatic gears well. It is very much like having a transmissions problem and in my situation that was what I thought was wrong with my GTA, but it turned out to only be the exhaust blockage. Yumiko
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Old 01-19-2008   #34
MunsonGTA
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Re: TPI problem

Quote:
Originally Posted by gtayumiko
Be careful when using carburator cleaner on sensors, it will ruin most sensors. Maybe it could be fine to use it on mechanical stuff to clean it, but do not use it on sensors that have a special coating on them because the cleaner will damage the special coatings.
i've used it on my throttle body a few times and never had any trouble with it. i mainly use it to clean out the passages, not the sensors themselves. usually it's the passages in the throttle body that clog up from oil build up, which causes the trouble, not the sensors themselves.
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87 GTA: Forged 408 LSX short block, TEA stage 2 cnc ported 243 heads, BTR Stage 3 stroker cam, Fast 102 intake, NW 102 TB, Longtube headers, custom 411 ECM, custom harness, custom tuned, Performabuilt stage 2 4l60E with PTC 2800 stall, 9 bolt rear with 3.70 gears and TAP girdle.

11.16 at 123 mph.
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Old 01-19-2008   #35
yves_transam
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Re: TPI problem

Quote:
Originally Posted by MunsonGTA
i've used it on my throttle body a few times and never had any trouble with it. i mainly use it to clean out the passages, not the sensors themselves. usually it's the passages in the throttle body that clog up from oil build up, which causes the trouble, not the sensors themselves.
all I would like to say is that when I screwed the iac scrw the tps value increased...

could you tell me whet is said in that words..I don't understand (I verify yumiko...there's nothing in my exhaust cause the cat is empty...)

this is the words I don't understand :
"To verify that our IAC valve was still working properly, we plugged it back into the harness connector and started the car. We immediately heard a massive intake leak,"

I don't understand...we plugged back into harness
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Old 01-19-2008   #36
gtayumiko
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Re: TPI problem

Quote:
Originally Posted by yves_transam
there's nothing in my exhaust cause the cat is empty...
You must not forget that the muffler could also be clogged. With the muffler, it will look fine on the outside but it has collapsed inside which means pieces of the inner sheet metals have come loose in most case because of rusting, and has fallen down and are now obstructing the flow of exhaust. But the outside of the muffler will look fine. Yumiko
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Old 01-19-2008   #37
yves_transam
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Re: TPI problem

Quote:
Originally Posted by gtayumiko
You must not forget that the muffler could also be clogged. With the muffler, it will look fine on the outside but it has collapsed inside which means pieces of the inner sheet metals have come loose in most case because of rusting, and has fallen down and are now obstructing the flow of exhaust. But the outside of the muffler will look fine. Yumiko
hummm will have a look tomorrow...could you answer to my last thread just below..the translation thanks
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Old 01-19-2008   #38
george88gta
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Re: TPI problem

Quote:
Originally Posted by yves_transam
all I would like to say is that when I screwed the iac scrw the tps value increased...

could you tell me whet is said in that words..I don't understand (I verify yumiko...there's nothing in my exhaust cause the cat is empty...)

this is the words I don't understand :
"To verify that our IAC valve was still working properly, we plugged it back into the harness connector and started the car. We immediately heard a massive intake leak,"

I don't understand...we plugged back into harness
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Old 01-19-2008   #39
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Re: TPI problem

OK, let me try this again. Lost all of the info in my previous response. There is no adjustment screw on the exterior of the IAC. The adjustment is to the internal front part, called the pintle. The IAC must be removed from the throttle body to do this adjustment. This adjustment is required when you change the IAC, to help the computer recalibrate the IAC. Sounds like you adjusted the mechanical idle speed screw on the drivers side of the throttle body. This screw is sealed from the factory and normally doesnt require adjustment. I do not believe that it should be screwed all the way in to make the engine run, something else is wrong. When you turn this screw, you change the position of the butterfly shaft, which changes the amount of air flow, at idle. This screw and the IAC work together with the computer to control air flow at idle. When you turn this screw, you change the position of the butterfly shaft which changes the internal position of the TPS. This is why you are seeing the TPS voltage change. Regarding your quoted info. It sounds like they removed the IAC, plugged it back in to the cable harness, but did not put it back in to the throttle body. This leaves a large hole in the throttle body which results in an air/vacumn leak.
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Old 01-19-2008   #40
MunsonGTA
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Re: TPI problem

if he is indeed adjusting the idle control screw, he would need to readjust the TPS after setting idle control screw to where he wants it.
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11.16 at 123 mph.
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