chris88z24

Fuel system cleaner is cheap.. dealer probably wants 100+ to clean the injectors. I had a 88 Z24 with 150,000 miles and the injectors were never cleaned. Just ran injector cleaner through it every once in a while. Car ran good as new when I sold it.. But yeah that clip is definitely the problem.

RMDCRA#55

if you keep it clean from the start it will never need cleaned and yes our prices are high but i don't own the **** hole I just work there and outtamymind you should follow the flow chart for your DTC's or symptoms list not just clean every thing to much of a good thing is bad for your health aka your car's health

First answer is yes second is no you will need a connector pinout and a scan tool and volt meter but try the gray clip and make sure all of your wires are in the connector tight pull on the wire straight back out of the connector they should stay in

The throttle position (TP) sensors 1 and 2 are located within the throttle body assembly. Each sensor has the following circuits:

• A 5-volt reference circuit

• A low reference circuit

• A signal circuit

This provides the powertrain control module (PCM) with a signal voltage proportional to the throttle plate movement. The TP sensor 1 signal voltage at closed throttle is near the 5-volt reference circuit and decreases as the throttle plate is opened. The TP sensor 2 signal voltage at closed throttle is near the low reference circuit and increases as the throttle plate is opened. If the PCM detects that the TP sensor 1 signal voltage is less than the predicted range, DTC P0122 sets.

DTC Descriptor
This diagnostic procedure supports the following DTC:

DTC P0122 Throttle Position (TP) Sensor 1 Circuit Low Voltage

Conditions for Running the DTC
• The ignition switch is in the Crank or Run position.

• DTC P0641 is not set.

• The ignition voltage is greater than 5.23 volts.

• DTC P0122 runs continuously when the above conditions are met.

Conditions for Setting the DTC
The PCM detects that the TP sensor 1 voltage is less than 0.27 volts for more than 0.4 seconds.

Action Taken When the DTC Sets
• The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.

• The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.

• The control module commands the TAC system to operate in the Reduced Engine Power mode.

• A message center or an indicator displays Reduced Engine Power.

• Under certain conditions the control module commands the engine OFF.

Conditions for Clearing the MIL/DTC
• The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

• Clear the MIL and the DTC with a scan tool.

Step
Action
Values
Yes
No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views

1
Did you perform the Diagnostic System Check - Vehicle?
--
Go to Step 2
Go to Diagnostic System Check - Vehicle

2
Turn ON the ignition, with the engine OFF.
Observe the Throttle Position (TP) Sensor 1 Voltage parameter, with the accelerator pedal in the rest position, with a scan tool.
Is the TP Sensor 1 Voltage parameter less than the specified value?
0.27 V
Go to Step 4
Go to Step 3

3
Observe the Freeze Frame/Failure Records for this DTC.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records .
Did the DTC fail this ignition ?
--
Go to Step 4
Go to Testing for Intermittent Conditions and Poor Connections

4
Turn OFF the ignition.
Disconnect the throttle body harness connector.
Turn ON the ignition, with the engine OFF.
Measure the voltage from the 5-volt reference circuit of the TP sensor 1 to a good ground with a DMM. Refer to Circuit Testing .
Does the DMM indicate voltage within the specified range?
4.8-5.2 V
Go to Step 5
Go to Step 6

5
Connect a fused jumper wire between the 5-volt reference circuit and the signal circuit of TP sensor 1.
Observe the TP Sensor 1 Voltage parameter with a scan tool.
Is the TP Sensor 1 Voltage parameter within the specified range?
4.8-5.2 V
Go to Step 11
Go to Step 7

6
Test the TP sensor 1 5-volt reference circuit for the following conditions:

• An open

• A short to ground

• High resistance

Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?
--
Go to Step 12
Go to Step 8

7
Test the TP sensor 1 signal circuit for the following conditions:

• An open

• A short to ground

• High resistance

Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?
--
Go to Step 12
Go to Step 8

8
Test for an intermittent and for a poor connection at the throttle body. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?
--
Go to Step 12
Go to Step 9

9
Test for an intermittent and for a poor connection at the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?
--
Go to Step 12
Go to Step 10

10
Replace the PCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?
--
Go to Step 12
--

11
Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement .

Did you complete the replacement?
--
Go to Step 12
--

12
Clear the DTCs with a scan tool.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?
--
Go to Step 2
Go to Step 13

13
Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?
--
Go to Diagnostic Trouble Code (DTC) List - Vehicle
System OK

outtamymind

rmd unfortuneatly there are no DTC's being set which is the problem.

RMDCRA#55

well that sucks

outtamymind

ya so this is the predicament i am in. if you go here https://www.cobaltss.net/forums/problems-service-maintenance-69/need-some-fresh-ideas-guys-124999/ i've listed everything that i have tested. the only thing i can think of is the #2 and #3 injectors are slightly clogged as the injector test showed #1 and #4 are showing a +% and #2 and #3 are showing a -% nothing huge but still a difference. thus trying to the fuel line cleaner.

and sorry for jacking the thread.

chris88z24

It's all good man.

I got another godforsaken CEL driving today. No reduced power, just a cel. I Hate new cars with a passion! Everything is controlled by the ******* computer!

chris88z24

It doesn't go into limp mode anymore, but the CEL still comes on randomly. I think it's because my battery cables aren't tightened becasue the one time I started it and the gauges freaked out and went to 0 when the car was started and the radio turned off and came back on.

Stupid car..

06blackg85ss

iTrader: (1)

lol, my car never throws cel's and every emission thing is gone, as is the s/c

Witt

I think that snail is eating all your codes.

06blackg85ss

iTrader: (1)

this is true lol

chris88z24

It never threw CEL's until I put the 3" on. STUPID CAR.

chris88z24

Put the new clip on, fired up the car, No cel! yay... until I went WOT in 2nd and BAM.. CEL, reduced power, car falls flat on its face. Pull in my driveway, wiggle the gay ass connector around a bit, fire up the car. No more reduced power, but the CEL is still there.

I think the TB has a short in it or something. Gonna make an appointment with the dealer (boo!) and have them fix it under warranty. This sucks.

chris88z24

bump, still have the problem. Going to try swapping TB's and see if the problem goes away. Would like to avoid the stealership if at all possible.

Witt

If you have HPTuners or access to it use this as an excuse to upgrade to an LS4 TB.

chris88z24

Maybe. It has to be something with this connector. Once it hits reduced power, I can pull over, shut the car off, and go under the hood and wiggle the connector around. Fire the car back up and BAM, full power once again until I start getting on the gas hard. If I keep it in vacuum it's ok, but any amount of sustained boost and it hits limp mode. So incredibly gay.

StraussiE WousiE

Limp mode? try Viagra

chris88z24

Found the problem! I took the TB off the car and looked at the pins in the connector, and one was bent!! Straightened it out and put it back on and voila, problem solved. Or so I thought. I did a 40 roll, and BAM! as soon as it got into high RPM's (above 5k) the car goes into severe limp mode, is misfiring, etc.

Pull over, wiggle the connector around, fire up the car. No more limp mode! I am going to go get hammered now because this is just ridiculous... pzz

chris88z24

**** Thsi Car!

chris88z24

Woah... I think the car magically fixed itself. I was driving it tonight, getting on it hard in 2nd and 3rd (took it up to about 100 or so WOT) and it never hit limp mode. Also hit 15psi this time, whereas the other times while going WOT it didn't seem to go past 12psi. I then parked it at my buddys house, and when I went to leave, I noticed the CEL had gone away! SWEET! Hopefully it stays this way *crosses fingers*

chris88z24

Took it up to redline WOT 2 or 3 times today, and shifted 3rd WOT. No limp mode or reduced power! Woot! I think that bent pin was the cause of the problem, although why it hit limp mode after I fixed it I am not sure. I wonder if that code was stored in the ECM, so when it saw WOT it freaked out and sent the car into limp mode? After driving for a while the CEL cleared itself, so maybe that whole "limp mode" thing cleared itself with the CEL? I have no idea.

But this is why I love GM cars. They fix themselves.

Avenger626

just so you know my friend, I have been dealing with EPR since last year and, the past few months straight, since may, I hit engine power reduced EVERY single day!!!!!!!! Im done with it man. Good luck and keep us updated!

brett5

well good luck make sure you hooked all your sensors back up to the supercharger too

chris88z24

It's back, and i'm ******* pissed off to no end. Only comes on during startup. I unplugged the battery and I went to start the car this morning and it came back on. I hammered it on the highway last night and it hit limp mode. I hate this piece of **** car. I honestly want to get rid of it. It's fun when it runs right, but god damn. I ran the codes last time, got a sc inlet sensor low voltage and some code to do with the ignition or something like that. I just stopped caring. SOmetimes the CEL goes away while driving, then comes back on during startup. I'm stumped.


Dirty MAF? I havn't cleaned my dryflow in 20,000 miles.. and i'm pretty sure it's gotten wet and had **** on it. So maybe the MAF is dirty or something? Not sure if that would cause a "low voltage" and "ignition" DTC's though..

wtpcobaltss

check all the sensors!! do you have a sound system wired into your stock head unit/?? Check your mass air flow..what size intake u running??? also look for a vaccum leak.. it seems as if ur car is getting to lean from unmetered air somwhere. ( thats why it does it at wot or when boosting.) hows ur afr??do u have a wideband? there could be a number of problems....

Cobaltss/TC

WOW holy revived thread batman................................