Question about 1994 Chevrolet S-10

2 Answers

Injectors not operating

Injectors have 12 v to them. not operating. it is a throttle body with2 injectors. pcm controls ground.i do have spark.inigition module is operating as far as spark goes.

Posted by on

  • drummin95 May 10, 2009

    just to explain this a little better- i have 60 psi fuel pressure and i did test with a noid light and i have no pulse.also i grounded the injectors and the fuel worked normal.i worked for gm for 13 years.i know what to check but i cant find the information to check the iginityion module and pcm inputs.also the dealer told me that this s10 also has a vcm beteween the inigition module and pcm.im thinking the pcm switch for grounding the injectors isnt operating.for the price of a pcm im tryin to find more information before buyin a pcm.any ideas?

  • drummin95 May 22, 2009

    jUST TO UPDATE MY SITUATION. GOT THE REST OF THE INFO I NEEDED AND AS I SAID BEFORE IT WAS THE PCM. PROBLEM RESOLVED. THANKS FOR THE HELP TO THOSE WHO GAVE INPUT. THANKS DRUMMIN

×

2 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    President:

    An expert whose answer got voted for 500 times.

  • Master
  • 1,263 Answers

Even though you have vol,tage to them you might have a pressure problem with the fuel getting to them check on your fuel pump relay it may be defective. if you turn the key you should hear the relay click and the fuel pump run. if the pump runs then check to se if you have good fuel pressure. if you have good pressur but still no fuel to the injectors its your pressure regulator to the injectors that need replaced

Posted on May 08, 2009

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 407 Answers

You need a noid lite to test injectors also its possiable you may have bad igition module even though you have spark

Posted on May 08, 2009

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Changed a throttle body assembly on a 2003 gnc Denali n no won't start any help


Do you know how electronic throttle control works ? Electronic Throttle Control System Diagnosis Diagnostic Quick Tips Snap on... Drive by Wire Function and diagnostics by Wells Do you know how to do electrical testing ? The APP an throttle body position sensors are powered by five volt ref. voltage form PCM . If this voltage circuit is shorted to ground it will bring down the PCM causing no start condition .

Oct 26, 2016 | 2003 GMC Yukon Denali

1 Answer

I need to know the code po120


Throttle Position Sensor/Switch (TPS) A Circuit Malfunction
The TPS (Throttle Position Sensor) is a potentiometer that is mounted to the throttle body. It detects the throttle blade angle. As the throttle blade moves, the TPS sends a signal to the PCM (Powertrain Control Module). Usually a three wire sensor: A 5 volt reference from the PCM to the TPS, a ground from the PCM to the TPS, and a signal return from the TPS to the PCM. The TPS sends the throttle position information back to the PCM on this signal wire. When the throttle is closed the signal is near .45 volts. At WOT (Wide Open Throttle) the TPS signal voltage will approach a full 5 volts. When the PCM sees a voltage that is outside of normal operating range, P0120 will set. NOTE: The PCM knows that any large change in throttle position means a cooresponding change in manifold pressure (MAP). On some models the PCM will monitor MAP and TPS operation for comparison. Meaning that if the PCM sees a large percentage change in throttle position, it expects to see a cooresponding change in manifold pressure and vice versa. If it doesn't see this comparitive change, P0120 may set.

Dec 11, 2014 | 2001 Toyota Sienna

1 Answer

1996 suburban getting fuel. To rail but not


loosen the fuel line at the throttle body to check for fuel, then you will have to check the injectors for power getting to them and for the ground operation. sounds like you may have an injector problem either not cycling or so dirty they can`t spray properly. the ECM grounds the circuit to open the injectors to spray fuel into the intake to burn.

Sep 11, 2014 | Cars & Trucks

1 Answer

Where is the throttle body fuse on 2008 toyota rav4


There is no "fuse" for the throttle body. The throttle body gets all of its power and ground from the Powertrain Control Module. If your throttle body (or accelerator) is not functioning properly, you need to scan your PCM to find out why.

Mar 06, 2012 | Toyota RAV4 Cars & Trucks

1 Answer

Where is the thorttleposition sensor on 2001jeep cherokee


The 3 wire Throttle Position Sensor (TPS) is mounted on the throttle body and is connected to the throttle blade.
The TPS is a 3wire variable resistor that provides the Powertrain Control Module (PCM) with an input signal (voltage) that represents the throttle blade position of the throttle body. The sensor is connected to the throttle blade shaft. As the position of the throttle blade changes, the resistance (output voltage) of the TPS changes.
The PCM supplies approximately 5 volts to the TPS. The TPS output voltage (input signal to the PCM) represents the throttle blade position. The PCM receives an input signal voltage from the TPS. This will vary in an approximate range of from .26 volts at minimum throttle opening (idle), to 4.49 volts at wide-open throttle. Along with inputs from other sensors, the PCM uses the TPS input to determine current engine operating conditions. In response to engine operating conditions, the PCM will adjust fuel injector pulse width and ignition timing.
The PCM needs to identify the actions and position of the throttle blade at all times. This information is needed to assist in performing the following calculations:

selectachapter.gif

Cherokee, Grand Cherokee, 1999-2005
Throttle Position Sensor

Print


Operation

The 3 wire Throttle Position Sensor (TPS) is mounted on the throttle body and is connected to the throttle blade.
The TPS is a 3wire variable resistor that provides the Powertrain Control Module (PCM) with an input signal (voltage) that represents the throttle blade position of the throttle body. The sensor is connected to the throttle blade shaft. As the position of the throttle blade changes, the resistance (output voltage) of the TPS changes.
The PCM supplies approximately 5 volts to the TPS. The TPS output voltage (input signal to the PCM) represents the throttle blade position. The PCM receives an input signal voltage from the TPS. This will vary in an approximate range of from .26 volts at minimum throttle opening (idle), to 4.49 volts at wide-open throttle. Along with inputs from other sensors, the PCM uses the TPS input to determine current engine operating conditions. In response to engine operating conditions, the PCM will adjust fuel injector pulse width and ignition timing.
The PCM needs to identify the actions and position of the throttle blade at all times. This information is needed to assist in performing the following calculations:


Ignition timing advance Fuel injection pulse-width Idle (learned value or minimum TPS) Off-idle (0.06 volt) Wide Open Throttle (WOT) open loop (2.608 volts above learned idle voltage) Deceleration fuel lean out Fuel cutoff during cranking at WOT (2.608 volts above learned idle voltage) A/C WOT cutoff (certain automatic transmissions only)


Removal & Installation

3.7L & 4.0L

  1. Disconnect TPS electrical connector.
  2. Remove TPS mounting screws.
  3. Remove TPS.

To Install:
The TPS is mounted to the throttle body. The throttle shaft end of throttle body slides into a socket in the TPS. The TPS must be installed so that it can be rotated a few degrees. (If sensor will not rotate, install sensor with throttle shaft on other side of socket tangs). The TPS will be under slight tension when rotated.
  1. Install TPS and retaining screws.
  2. Tighten screws to 7 Nm (60 inch lbs.) torque.
  3. Connect TPS electrical connector to TPS.
  4. Manually operate throttle (by hand) to check for any TPS binding before starting engine.

4.7L
  1. Remove air duct and air resonator box at throttle body.
  2. Disconnect TPS electrical connector.
  3. Remove two TPS mounting bolts (screws).
  4. Remove TPS from throttle body.

To Install:
The throttle shaft end of throttle body slides into a socket in TPS. The TPS must be installed so that it can be rotated a few degrees. If sensor will not rotate, install sensor with throttle shaft on other side of socket tangs. The TPS will be under slight tension when rotated.
  1. Install TPS and two retaining bolts.
  2. Tighten bolts to 7 Nm (60 inch lbs.) torque.
  3. Manually operate throttle control lever by hand to check for any binding of TPS.
  4. Connect TPS electrical connector to TPS.
  5. Install air duct/air box to throttle body.

Hope this helps

Dec 31, 2011 | 2001 Jeep Grand Cherokee

1 Answer

1999 Ram 3500 Wagon with 5.9L has eng Lt on. Idles high at red lights & surges at times. Code scanned is P0505. Do I need idle control valve or computer to make control valve work properly.


The IAC stepper motor is mounted to the throttle body, and regulates the amount of air bypassing the control of the throttle plate. As engine loads and ambient temperatures change, engine rpm changes. A pintle on the IAC stepper motor protrudes into a passage in the throttle body, controlling air flow through the passage. The IAC is controlled by the Powertrain Control Module (PCM) to maintain the target engine idle speed.

At idle, engine speed can be increased by retracting the IAC motor pintle and allowing more air to
pass through the port, or it can be decreased by restricting the passage with the pintle and diminishing the amount of air bypassing the throttle plate.
The IAC is called a stepper motor because it is moved (rotated) in steps, or increments. Opening the IAC opens an air passage around the throttle blade which increases RPM.

The PCM uses the IAC motor to control idle speed (along with timing) and to reach a desired MAP during decel (keep engine from stalling).

The IAC motor has 4 wires with 4 circuits. Two of the wires are for 12 volts and ground to supply electrical current to the motor windings to operate the stepper motor in one direction. The other 2 wires are also for 12 volts and ground to supply electrical current to operate the stepper motor in the opposite direction. To make the IAC go in the opposite direction, the PCM just reverses polarity on both windings. If only 1 wire is open, the IAC can only be moved 1 step (increment) in either direction. To keep the IAC motor in position when no movement is needed, the PCM will energize both windings at the same time. This locks the IAC motor in place.

In the IAC motor system, the PCM will count every step that the motor is moved. This allows the
PCM to determine the motor pintle position. If the memory is cleared, the PCM no longer knows the position of the pintle. So at the first key ON, the PCM drives the IAC motor closed, regardless of where it was before. This zeros the counter. From this point the PCM will back out the IAC motor and keep track of its position again.

When engine rpm is above idle speed, the IAC is used for the following:
  • Off-idle dashpot (throttle blade will close quickly but idle speed will not stop quickly)
  • Deceleration air flow control
  • A/C compressor load control (also opens the passage slightly before the compressor is engaged so that the engine rpm does not dip down when the compressor engages)
  • Power steering load control
The PCM can control polarity of the circuit to control direction of the stepper motor.

Solutions:
  1. First, try removing the IAC Valve, and cleaning the valve and the opening in the throttle body where the IAC Valve installs using Carburetor Cleaner. Ensure that the IAC Valve hole in the throttle body is not clogged, and is free from carbon deposits, etc. Have the ECM reset and check for the problem again.
  2. If the Check Engine Light comes back on, replace the IAC Valve. Have the ECM reset and check for the problem again.
  3. If the Check Engine Light still comes on, although highly unlikely, you may have a clogged throttle body, faulty wiring or connector, or faulty ECM (very unlikely since the vehicle runs).

Apr 13, 2011 | 1999 Dodge Ram

1 Answer

Hyundai diesel has a problem in the throttle i have cod P 201


P0201 - Injector Circuit Malfunction Cylinder 1

The Powertrain Control Module (PCM) or Electronic Control Module (ECM) checks the injectors circuit resistance and monitors the voltage drop during normal operation. The PCM/ECM will trigger the P0201 code when the resistance or voltage drop at the injector #1 is out of specifications.

Causes:
- Open or shorted wiring harness to the injector #1
- Bad injector #1
- Bad PCM or ECM

Solutions:
- If damaged, repair injector wire harness or connector
- Replace injector
- Replace PCM or ECM

Feb 04, 2011 | 2006 Hyundai Sonata

3 Answers

Hi I have an 87 s10 blazer 2.8L 4x4 and does not want to spray fuel into the throttle positioning sensor but fuel goes to and from it, I've checked the fuses replaced the fuel pump, it will fire with ether...


One side of the injector plug at each of the two injectors has 12 volts key on engine off.
The other side is grounded by the PCM computer to fire the injectors.
Put a test light across one of the injector plugs while cranking, Watch for flashing.

Jan 27, 2011 | 1987 Chevrolet Blazer

1 Answer

I have a 1995 Saturn SL1. It was running on 3


Have you resistance checked the injectors. If the resistance is wrong the pcm will shut the injector drivers down.

Mar 31, 2010 | 1995 Saturn Sl

2 Answers

I have fuel pressure but the engine wont start unless i spray starting fluid into the intake. the injectors arent working? could it be the pcm is bad?


Not likely. I believe the injectors have 12 volts going to them all the time. The PCM then grounds them so they operate when the crankshaft or camshaft sensor tell the PCM when the cylinder is on compression stroke.

I would check for an injector fuse first (see owner manual), and then check to see if you have a bad crank or camshaft sensor.

The PCM very rarely fails.

Section 03-14: Engine Controls, Electronic 1994 All Aerostar, Ranger, and Explorer Vehicles Workshop Manual
DESCRIPTION AND OPERATION Powertrain Control Module (PCM) The center of the EEC-IV system is a microprocessor called the powertrain control module . It receives data from various sensors:
  • Throttle position sensor (TP sensor) (9B989)
  • Mass airflow sensor (MAF sensor) (12B579)
  • Intake air temperature sensor (IAT sensor) (12A697)
  • Engine coolant temperature sensor (ECT sensor) (12A648)
  • Heated oxygen sensor (HO2S) (9F472)
  • Camshaft Position (CMP) Sensor
  • Crankshaft position sensor (CKP sensor) (6C351)
  • Power Steering Pressure (PSP) Switch
The powertrain control module contains specific calibrations for optimizing emissions controls, fuel economy, and driveability. Based on information received and programmed into its memory, the processor sends signals to control various actuators:
  • Fuel injector nozzle tip (9E527)
  • Ignition coil (12029)(s)
  • Idle air control valve (IAC valve) (9F715)
  • Ignition control module (ICM) (12A297)
  • EGR vacuum regulator control (9J459)
  • EGR external pressure valve (9F483)

Aug 27, 2009 | 1987 Ford Aerostar

Not finding what you are looking for?
1994 Chevrolet S-10 Logo

Related Topics:

184 people viewed this question

Ask a Question

Usually answered in minutes!

Top Chevrolet Experts

yadayada
yadayada

Level 3 Expert

75797 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22114 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

8152 Answers

Are you a Chevrolet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...