Just tryed the ECU reset, no dice....Everything is the same............I went back to Advance and had it rescanned, it has the same trouble codes. I wrote them down, they are: PO304 misfire cylinder 4, PO200 injection circuit open, and PO141 O2 sensor. I will try the testing you suggested above a little later, but I wanted to get the codes to you right away in case they will give you some insight.
Help rough running Sonoma
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Molson02536
New member
The P0304 and P0141 is most likely caused by the P0200 issue. The p0141, your going to have to remove the O2 sensor and try to clean out the carbon build up or once the engine is running 100% it may clean it self out after a few days of running on the highway for long period of times.
As for the P0200 here is some information that should help you.
This step tests for voltage at the fuel injector harness connector. The Injector fuse supplies power to the coil side of the fuel injector harness connector. If the fuse is open, a short to ground on the fuel injector B+ supply circuit is indicated. The Injection fuse also supplies voltage to the ignition coils. If the fuse is open, inspect the circuits to the ignition coils for a short to ground.
This step verifies that the PCM is able to control the fuel injector. If the test lamp blinks, then the PCM and the wiring are OK.
This step tests if a ground is constantly being applied to the fuel injector.
Fuel Injector Circuit Check Step
Action
Yes
No
Schematic Reference: Engine Controls Schematics
1
Did you perform the Diagnostic System Check-Engine Controls?
Go to Step 2
Go to Diagnostic Starting Point - Engine Controls
2
Use a scan tool in order to clear the DTCs.
Idle the engine at the normal operating temperature.
Use a scan tool in order to monitor the misfire current counters.
Are any of the misfire current counters incrementing?
Go to Step 4
Go to Step 3
3
Observe the Freeze Frame and/or Failure Records data for this DTC.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text or as close as possible to the Freeze Frame and/or Failure records data that you observed.
Does the DTC fail this ignition?
Go to Step 4
Go to Diagnostic Aids
4
Turn OFF the ignition.
Disconnect the appropriate harness connector of the fuel injector.
Turn ON the ignition, with the engine off.
Probe the ignition voltage circuit of the fuel injector with a test lamp connected to a good ground.
Does the test lamp illuminate?
Go to Step 5
Go to Step 11
5
Connect the fuel injector test lamp J 34730-405 between the control circuit and the ignition voltage circuit of the fuel injector harness connector.
Start the engine.
Does the test lamp blink?
Go to Step 9
Go to Step 6
6
Does the test lamp remain illuminated at all times?
Go to Step 8
Go to Step 7
7
Test the control circuit of the fuel injector for a short to voltage or for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 14
Go to Step 10
8
Test the control circuit of the fuel injector for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 14
Go to Step 13
9
Inspect for poor connections at the harness connector of the fuel injector. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition?
Go to Step 14
Go to Step 12
10
Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition?
Go to Step 14
Go to Step 13
11
Important: The INJ fuse also supplies voltage to the ignition coil modules. If the fuse is open, inspect all related circuits for a short to ground.
Repair the ignition voltage circuit of the fuel injector for an open or for a short to ground. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?
Go to Step 14
--
12
Replace the fuel injector. Refer to Fuel Injector Replacement .
Did you complete the replacement?
Go to Step 14
--
13
Replace the PCM. Refer to Powertrain Control Module Replacement .
Did you complete the replacement?
Go to Step 14
--
14
Use the scan tool in order to clear the DTCs.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC run and pass?
Go to Step 15
Go to Step 2
15
Use a scan tool in order to observe the stored information, Capture Info.
Does the scan tool display any DTCs that you have not diagnosed
Molson02536
New member
Positive side to your injector should be constant 12V, the negative side should be the side that pulses. If the negative side is constant, there is a ground issue to your wire leads to that lead wire. As mentioned earlier, you can place the positive side to your multimeter to the batter and the other to the negative side of the injector lead wire and see if the negative side is pulsing. If it's constant, then there is a ground issue to that wire lead. You can compare your findings with the other injector lead harness.
#5 on the link is your Fuel injector Harness. Inspect for any signs of corrosion or damage that may be causing the ground issue to your injector and work your way back to the ECM.
http://www.compnine.com/index.php?u...delid=7078&capuid=1&majorgroup=02&grouptype=B
#525 is the harness to the fuel injectors on the rail.
http://www.compnine.com/index.php?u...delid=7078&capuid=1&majorgroup=03&grouptype=B
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Positive side to your injector should be constant 12V, the negative side should be the side that pulses. If the negative side is constant, there is a ground issue to your wire leads to that lead wire. As mentioned earlier, you can place the positive side to your multimeter to the batter and the other to the negative side of the injector lead wire and see if the negative side is pulsing. If it's constant, then there is a ground issue to that wire lead. You can compare your findings with the other injector lead harness.
#5 on the link is your Fuel injector Harness. Inspect for any signs of corrosion or damage that may be causing the ground issue to your injector and work your way back to the ECM.
http://www.compnine.com/index.php?u...delid=7078&capuid=1&majorgroup=02&grouptype=B
#525 is the harness to the fuel injectors on the rail.
http://www.compnine.com/index.php?u...delid=7078&capuid=1&majorgroup=03&grouptype=B
I don't know which side/leg of the connector is positive or negative but my test light or meter would read no voltage with key switch on and engine off. I checked touching both legs of the connector at once then each leg to ground strap, nothing.
Also the pulse check says to pull the ignition fuse turn over engine and observe for a blinking light. There are 2 ign fuses A&B a 40 and a 50 amp. I don't know which to pull to do that test.
Molson02536
New member
"Remove the injector electrical connector, turn the key to the on position without starting the engine. This test will tell you if the computer has proper system voltage and injector trigger signal. Remove an electrical connector from a fuel injector. Probe both sides of the connector with a grounded test light or multimeter (voltmeter). Set the voltmeter to DC voltage. Have a helper turn the key to the "on" position without cranking the engine and observe.
The test light/voltmeter should illuminate/read one side of the connector. The multimeter should read about 12 volts. Next, switch the test light or multimeter (voltmeter) lead (black) or to the positive side of the battery to test the system ground injector trigger. Disable the ignition system so the engine will not start (disconnect ignition coil or remove the ignition fuse). Probe the side of the connector that did not light up in the previous step, have a helper crank the engine over and observe the test light, it should blink on and off or the multimeter (voltmeter) should bounce from 0 to 12 volts. (Note: if no injector pulse and there is a constant 12 volt, there is a short in the ground injector trigger) Moisture can cause the injector connection to short circuit. Always inspect and clean all electrical connections at the fuel injector.
Keep me posted" IF you know where the Fuel pump relay is, pull that. We just want to crank the engine with the ignition and fuel injectors working without the engine running so we don't loose a finger or arm. It looks like that we need the system in working order to have the injection pulse. Well figure this out soon and hope it's just a bad wire that is shorting and not a bad diode in the ECM.
Just take you time, i know it's frustrating at times and don't get confused on the two ways i gave you on how to test. This is one way in this replay and the other on post #24. I was just trying to make it easier for you on which one you can understand more, but they both do the same.
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Ok I took your advice pulled the fuel pump breaker and did the test. Results: Test 1. With test light probe to positive side of connector, helper turns on ignition, test light comes on for maybe 1-2 seconds and goes back out. Test 2. With test light connected to negative side of connector and fuel pump disabled, helper turns engine over for 10 seconds, no light or flash, repeat and no light or flash.
Molson02536
New member
Was the other side of the probe connected to the positive side of the batter?? Remember we are testing the negative side of the injector wire leads to make sure it's not grounding out giving you a constant reading. It should pulse as compared to the other injection pulses.
I had i same issues when i did my HP upgrade on my Jimmy and that was alot of sleepless nights.
Was the other side of the probe connected to the positive side of the batter?? Remember we are testing the negative side of the injector wire leads to make sure it's not grounding out giving you a constant reading. It should pulse as compared to the other injection pulses.
I had i same issues when i did my HP upgrade on my Jimmy and that was alot of sleepless nights.
No, the test light was connected to the ground strap on the firewall for both tests whil I probed the connector pins. I'm not sure if you mean one or both of the tests should be done while connected to the positive terminal of the battery. Sorry to be dumb but I need clarity.
Ok second series of tests complete. These tests were completed with a test light and a volt meter for confirmation and the fuel pump circuit breaker pulled. Additionally I connected test light to the positive battery terminal then to the pos and neg pins of the injector connector. Test 1: The positive side pin in injector connector lights and reads 12.4 volts with ignition key off or on, makes no difference. Test 2: Test light does pulse or flash when connected from pos. terminal of battery to the neg. pin of the injector connector when the engine is turned over by a helper. Rechecked this 3X.
Molson02536
New member
That's a good thing, try swapping out the injector with another injector and see if the issue moves to the other cylinder to see if the fuel injector is bad. Keep me posted and cross the fingers.
Thats just the thing, when it was originally scanned for misfire cylinder 4, I replaced number 4 injector. It is brand new.
Molson02536
New member
Yes i know, you mentioned it earlier. But it's worth a try to see if the issues still there and if it's then it must be the injector pulse being to long for that injector and we can go from there. At least we know your wire leads and PCM is still good and what's your fuel pressure reading at your shredder valve??
When the ignition switch is ON and the fuel pump is running, the fuel pressure indicated by the fuel pressure gage should be 284-325 kPa (41-47 psi) . This pressure is controlled by the amount of pressure the spring inside the fuel pressure regulator can provide. When the engine is at idle, the manifold pressure is low (high vacuum). This low pressure (high vacuum) is applied to the fuel pressure regulator diaphragm. The low pressure (high vacuum) will offset the pressure being applied to the fuel pressure regulator diaphragm by the spring inside fuel pressure regulator. When this happens, the result is lower fuel pressure. The fuel pressure at idle will vary slightly as the barometric pressure changes, but the fuel pressure at idle should always be less than the fuel pressure noted at 47 psi with the Engine OFF
A rich condition may result from the fuel pressure being above 325 kPa (47 psi). A rich condition may cause a DTC P0132 or a DTC P0172 to set. Driveability conditions associated with rich conditions can include hard starting (followed by black smoke) and a strong sulfur smell in the exhaust.
This test determines if the high fuel pressure is due to a restricted fuel return pipe or if the high fuel pressure is due to a faulty fuel pressure regulator.
A lean condition may result from the fuel pressure being below 284 kPa (41 psi). A lean condition may cause a DTC P0131 or a DTC P0171 to set. Driveability conditions associated with lean conditions can include hard starting (when the engine is cold), hesitation, poor driveability, lack of power, surging, and misfiring.
Restricted return fuel line causes the fuel pressure to rise above the regulated fuel pressure. The fuel pressure should not rise above 325 kPa (47 psi) or there may be injector issues. .
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Just to let everyone know, my hunch was correct. The faulty ECM was sending bad signals to the injectors "WOT" flooding the engine and that set off the O2 sensor with raw fuel. I bought a reconditioned ECM thru Autozone for $115. exchange and she runs like new again. Now I'll just change the fuel saturated oil out and I'm good to go. $115. bucks sure beats the $1400 + the stealer wanted. Txs for all your help.