dies at idle and to much gas when drivingn help!

[98chevys10]

Thanks MT

Also when i took it to sears they said that there was dtc-171 engine running lean in (bank 1)

Also i check the MAP sensor for voltage and it was fine right at 5v

Then when i check the TPS (with car running) it was at 12.85v and when i gave it gas it was jumping all over the place and going into the negatives as well. but not higher then 12.85v but isnt 12.8v at idle way to high to start with?

And do you know any websites where i can review the Flow charts I also have the Haynes Repair Manual if know what that is and if it might help.

Thanks again.

I still need to do a fuel pressure check, just dont have the tools right now, let me know if anything else comes to mind with the new info givin.

Thanks again.

Happy 4th AF.

[MT-2500]

Very strange readings.
You might try Auto Zone web site.

But the good ones is.
http://www.alldata.com/products/diy/index.html
Or Mitchell on demand DIY

[MT-2500]

Try all data or Mitchell on demand online diy
Also Auto Zone web site may have some in formation.

[98chevys10]

Hmm. do you know of one that is free?

I couldnt find what i was looking for on the autozone website but i dont know much about flow charts,

Thanks

[MT-2500]

Map sensor and TPS reference voltage key on feed to sensor should be .5 volts .
May sensor to computer reading should be 1.0 to 1.5 volts at idle and 4.0-4.6 wide open throttle.
TPS sensor voltage at closed throttle should be about .6 voltage and swing up with no drop outs or glitz's to 4.8 volts wide open throttle.

If you are getting 12 volts something is way wrong or you are on wrong sensor or wire.

Get a good wiring diagram and make sure you are o right sensor and wires.

Tps sensor feed wire to computer is dark blue C.
Map sensor to computer feed wire may be black/white wire.

[MT-2500]

Originally Posted by 98chevys10

Hmm. do you know of one that is free?

I couldnt find what i was looking for on the autozone website but i dont know much about flow charts,

Thanks

Not much good free stuff left.
Try your public library's.
Some have car repair info.
but in 5 minutes with all data diy or mitchell on Demand DIY on line and a plastic card you can be set to go.
Good Luck and let us know how it goes.

[Airjer_]

Check with your local library. Many of them across the country will have free alldata. They usually charge for everything you print out but a couple bucks will get you in the right track

[98chevys10]

Ok so i was reading the wrong sensor there are 2 sensors on the TB one on top and one on the side of the TB toward the front of the car... i was reading the one on the top of the TB (not sure what sensor that is.. but im guessin the Tps sensor is the one on the side...) can someone let me know please... also what is the differance between checking the reference voltage from the pcm im asuming the grey and black wires coming out of the pcm? and the tps signal voltage? im guess thats the females in the sensor? once i get these answer ill repost the to correct readings.. thanks again guys sorry its been awhile since ive worked on a car haha

[98chevys10]

Ok so for an update, I was checking the reference voltage of my MAP sensor with then engine off and the key on I was getting 5 volts which is perfect i think.

Then when I checking the signal voltage with the engine running I read its should be 1.5-2.0 volt at idle. my reading was just about 1.25volts

And then I read that the MAP sensor at wide open throttle should increase to 4.5-5.0 volts. My reading at about half way to wide open throttle would peak at 1.60 volts to wide open throttle it would drop to a low of .98 volts

so Im guess that i need to replace the MAP sensor. Also then if i have a bad map sensor can that also trigger the TPS code that i got or is that another problem all together?

When I test my tps for reference voltage with with key on car not running i got 5.05 volts which is perfect.

But i didnt understand how to check the TPS signal with the sensor plugged in? if anyone can help me out on that that would be great.

Thank again guys for the help i have a feeling im close to getting the truck running!

[MT-2500]

Originally Posted by 98chevys10

Ok so for an update, I was checking the reference voltage of my MAP sensor with then engine off and the key on I was getting 5 volts which is perfect i think.

Then when I checking the signal voltage with the engine running I read its should be 1.5-2.0 volt at idle. my reading was just about 1.25volts

And then I read that the MAP sensor at wide open throttle should increase to 4.5-5.0 volts. My reading at about half way to wide open throttle would peak at 1.60 volts to wide open throttle it would drop to a low of .98 volts

so Im guess that i need to replace the MAP sensor. Also then if i have a bad map sensor can that also trigger the TPS code that i got or is that another problem all together?

When I test my tps for reference voltage with with key on car not running i got 5.05 volts which is perfect.

But i didnt understand how to check the TPS signal with the sensor plugged in? if anyone can help me out on that that would be great.

Thank again guys for the help i have a feeling im close to getting the truck running!

Reference voltage is key on or engine running power to sensor.
4.5 to 5 volts is good for both sensors.


Check map sensor voltage to computer with engine running.
Check TPS sensor with key on engine off.

Sensor voltage to computer is what you need to watch and check.

Map sensor voltage to computer changes with engine load engine vacuum.

Map sensor voltage should not affect TPS but a bad TPS sensor may change map sensor reaqding when the map sensor is good.
Or change map sensor readings or even set a map sensor code

Around 1 to 1.25 volts at idle is good.
And should swing to 4 -4.5 volts full engine load.
With tps sensor plugged up and key on engine off.
Check and watch your TPS sensor voltage to computer.
Check that with key on engine off.
You should have .5 to 1 volts at closed throttle.
And should swing to 4.5 volts wide open throttle with no drop outs or glitz.
Glitz and dropouts may not show up on a volt meter.
A lab scope is the only true test on a tps sensor.

If you are still getting a TPS sensor code after code clear and driving I would replalace TPS sensor and adjust if adjustable and see what that does.

Let us know how that goes.

[Airjer_]

Originally Posted by 98chevys10

But i didnt understand how to check the TPS signal with the sensor plugged in? if anyone can help me out on that that would be great.

One wire is the 5 volt reference, one wire is ground, one wire is the signal return. With the sensor plugged in backprobe the signal return wire with a small paper clip or a pin. Turn the key on and slowly move the throttle from fully closed to fully open.

[98chevys10]

Originally Posted by MT-2500

Reference voltage is key on or engine running power to sensor.
4.5 to 5 volts is good for both sensors.


Check map sensor voltage to computer with engine running.
Check TPS sensor with key on engine off.

Sensor voltage to computer is what you need to watch and check.

Map sensor voltage to computer changes with engine load engine vacuum.

Map sensor voltage should not affect TPS but a bad TPS sensor may change map sensor reaqding when the map sensor is good.
Or change map sensor readings or even set a map sensor code

Around 1 to 1.25 volts at idle is good.
And should swing to 4 -4.5 volts full engine load.
With tps sensor plugged up and key on engine off.
Check and watch your TPS sensor voltage to computer.
Check that with key on engine off.
You should have .5 to 1 volts at closed throttle.
And should swing to 4.5 volts wide open throttle with no drop outs or glitz.
Glitz and dropouts may not show up on a volt meter.
A lab scope is the only true test on a tps sensor.

If you are still getting a TPS sensor code after code clear and driving I would replalace TPS sensor and adjust if adjustable and see what that does.

Let us know how that goes.

So I should replace my MAP sensor because with wide open throttle im getting a reading of under 1.0 volts, I think im just going to replace both parts. but are you also saying that even tho my MAP is reading .98volt at wide open throttle this could be caused by TPS so then if im going to replace both parts start with my tps then?

Thanks.

[98chevys10]

Originally Posted by Airjer_

One wire is the 5 volt reference, one wire is ground, one wire is the signal return. With the sensor plugged in backprobe the signal return wire with a small paper clip or a pin. Turn the key on and slowly move the throttle from fully closed to fully open.

OK so with the sensor plugged in I probe the back of the sensor with 2 paper clips? so just stick them all the way in they will go through the rubber backing? then there are 3 wires on the TPS so (+) on the dark blue wire, and (-) on the black wire? If that is right I did try that and i got no reading from the paperclips.. I might not have pushed them far enough into the back of the plug for fear of damaging the part also it is pretty tricky to get a reading on the TPS with how its placed on the 2.2L 4 banger.

Thanks

[98chevys10]

Ok so I replaced the MAP sensor and it fixed the problem i was having at idle... but when Im driving car car its still acting up and sputter like it did before but it did not die out just sputter really bad so im guessing this is the TPS sensor? any ideas thanks

[MT-2500]

29 post and you are still guessing?

Have you done any of the proper testing or listened to what we have tried to tell you?