engine vibration and power dropping

[yazan]

hi , first i got p0300 , and flashing SES light and engine Jerking, rough idling, hesitate even at accelerate and poor power , amp gauge moving up and down, and all lights is flickering ..
so i changed sparks plugs with recommended acd's iridium , TB cleaned , replaced fuel filter but no change , then i start to disconnect coils one by one to check what coil is not making different
i found that there is 2 coils not making any change , i swapped coils ( hoping to get any of the p0301-306 code ) but no luck
i replaced the 2 coils with new acd's , ok no more p0300 until now , but i got p0340 and p0113 with bad power and amp gauge moving and flicking lights and hesitating ...etc( same mentioned above )


any help with this is deeply appreciated ,

 

[mrrsm]

The PXXX Trouble Codes point to these problems:

(1) P0300 = Random Mis-Fires
(2) P0340 = Camshaft Position Sensor Fault (CPS)
(3) P0113 = Inlet Air Temp Sensor (IAT) High Side Fault

With the P0340 Error Code... If the CPS (Camshaft Position Sensor) has problems... The Ignition Firing /Timing will be thrown off enough to cause the P0300 Random Misfires. This is an easy and fairly inexpensive fix. You might also consider pulling and cleaning the screens on the CPAS (Camshaft Position Actuator Sensor) and note that if the Electrical Plug Connector is filled with Motor Oil... the CPAS will need to be replaced and the Connector needs to be sprayed out with CRC Electrical Connector Spray... Do Not Use Brake Cleaner. Here are some Helpful How To Videos:

From the Legendary GMT Nation Member, @MAY03LT on How to Diagnose the CPS:

How to Change the CPS:

How to R&R the CPAS:

After doing this work... Clear the Codes and watch for the IAT to fail... if Not... and the engine idles well... You're Done!

 

[yazan]

thanks very much for the helpful answer , yes i notice there is some oil in the CPAS connector . i cleaned both cpas + cps connectors with electrical cleaner , after that i got the p0340 .
i will order new CPAS & CPS and keep updating here

any programming / relearning needed after replacing both cpas & cps ?

the words in not enough to thank you

 

[Mooseman]

No programming or relearning needed on those.

 

[yazan]

waiting for CPAS & CPS Sunday
i used the torque misfire info , history and current , i drive for 30 minutes , no records! its indicates green as available pid , but no data only zero "no misfiring readings"
does this make sense ?

 

[mrrsm]

The Question is... How is the SUV Running right now? ... Did you accidentally clear the codes during the Test Drive? Most of the time... unless the Mis-Fires saturate enough to cause the RPM of the engine to diminish by 2% of the expected performance vs. MPH... then the P0300 Code will NOT set and get stored in the PCM.

This is an afterthought... but I'm hoping you made the choice to stick with the ACDelco OEM Flavor for the CPAS ... as there are some that do not perform as well and reliably after the R&R. The CPS ...? Not so OEM dependent as long as it is a Quality Sensor.

 

[yazan]

the engine still runs bad , same as before, and no i didn't clear the codes because iam hoping it will throw specific cylinder code ,
and yes its ACD's , iam a big fan of acdelco stuff ( except for fan clutch ) coils , sparks , sensors (cpas and cps) , fuel filter all acdelco ,

really appreciating your help

 

[yazan]

update >>>
1- i am still getting p0300 until yesterday , ( before changing cpas )
2 - torque pro app cannot read any misfiring data ( current and history )
3 - CPAS & CPS replaced today
4- after replacing CPAS & CPS >> p0303 set
5- torque pro app now detect and show misfiring info ( not showing before replacing cpas )
6 - even the new coil is showing misfiring data in "current and history" but its less than coil no3

 

[yazan]

and still have the "engine Jerking, rough idling, hesitate even at accelerate and poor power , amp gauge moving up and down, and all lights is flickering .."

 

[budwich]

were you playing with the battery cables / connections? check, clean, and tighten.

 

[yazan]

were you playing with the battery cables / connections? check, clean, and tighten.

i sanded the connectors from carbon and rust , cleaned and tighten them ... no effect

 

[mrrsm]

So far… your diagnostic approach cannot be faulted as you are dealing with a 16 Year Old SUV and those actions you have taken to date follow the proper things to investigate and replace. The next important thing to look at is your Cylinder Compression… and you can select a Kit that suits your price point vs. quality. Fortunately… with an In-Line (6) Cylinder Engine… this is a fairly straightforward procedure for both Dry and Wet Compression Testing.

Here are the Tools needed:

https://www.amazon.com/s/ref=nb_sb_ss_i_2_16?url=search-alias=aps&field-keywords=compression+tester+automotive&sprefix=compression+test,aps,390&crid=2EAX0IYAZOPY7

...and here is how this job gets done.... after you pull the Fuel Pump Relay so the EFIs don't flood the Engine with Raw Fuel:

 

[budwich]

i sanded the connectors from carbon and rust , cleaned and tighten them ... no effect

that just means that you did nothing to change the outcome.

back to your "observation" about the lights and such.... was this when the engine is about to die or when it is running at some "reasonable" rpm such that the engine is turning "well enough" to ensure proper "alternation" of electrical power. IF it is "at speed", then your issue is electrical in nature as opposed to engine "mechanical". You need to head in that direction checking things like grounds and such especially assoicated with the PCM (most likely a ground). Others will likely pipe in as to the most likely ground connection (I have seen many posts on this but have failed to mark them in my browser or mind... ... but there is one ground that can cause lots of problems with lights / gages and maybe even PCM.

 

[Mooseman]

Just as a quick elimination test, swap the #3 coil with maybe one of the new ones, clear the codes and see if the misfire moves with it. Check that all are connected properly.

A compression test is a good idea as well to eliminate a mechanical issue.

After that, you're looking at checking things like fuel trims, misfire data, O2 sensor data. Do you have a Bluetooth OBD reader with a good app like Torque Pro?

 

[benz01]

I am having the exact same symptoms with my ‘03 EXT. I took it to AutoZone yesterday to have the codes read and there a no stored codes. We checked it twice.

It has 142k miles on it. Plugs were changed in 2011 about 65k miles ago, coils have never been changed. Recently replaced fuel filter, air filter, and clean the throttle body. My thought was to replace the coils and plugs. Any thoughts or advice?

P.S. - Not intending to hijack this thread. I can repost as new if that is preferred.

 

[Mooseman]

I'd throw some new plugs in there first before throwing coils at it.

 

[yazan]

problem fixed finally ,
i swapped the coils an , erased the codes , drive for test and scan the dtc , i got another codes p0301 p0304 so it was a brand new bad coil and another bad coil but it was not detected the misfiring before swapping the coils ! no explain for this !?

now thanks god , the engine run smoother and better idle.
i replaced CPAS & CPS & fuel filter , sparks ,3 coils , TB cleaned , 2 bottles fuel injector cleaner added to fuel tank ,

but still have some weird things ( when i release the accelerating pedal the rpm go under 0.5 and engine is like going to stall ) but its mutch better than before


@MRRSM @Mooseman @budwich thanks you very much for your help

 

[yazan]

I am having the exact same symptoms with my ‘03 EXT. I took it to AutoZone yesterday to have the codes read and there a no stored codes. We checked it twice.

It has 142k miles on it. Plugs were changed in 2011 about 65k miles ago, coils have never been changed. Recently replaced fuel filter, air filter, and clean the throttle body. My thought was to replace the coils and plugs. Any thoughts or advice?

P.S. - Not intending to hijack this thread. I can repost as new if that is preferred.

in my problem , before replacing cpas & cps it was throwing p0300 " random misfire " all the time , no specific cyl code , even after replacing the sparks .
but after i replaced the cpas and cps "as advised above from @MRRSM " i can detect specific misfiring codes , and torque pro android app can read misfiring data now ,


good luck in fixing your problem

 

[yazan]

P0113 set again

 

[budwich]

from the "ramble", it doesn't appear that you have done anything with the sensor. check the wiring and maybe consider replacing the sensor. If the sensor is not right, you will have fuel air mixture issues and the things that go along with it. are your lights still flickering?

 

[yazan]

from the "ramble", it doesn't appear that you have done anything with the sensor. check the wiring and maybe consider replacing the sensor. If the sensor is not right, you will have fuel air mixture issues and the things that go along with it. are your lights still flickering?

i cleaned it with crc electric cleaner , and connectors cleaned , the p0113 set in same time with p0300 & p0340
and no , no flickering,

 

[benz01]

in my problem , before replacing cpas & cps it was throwing p0300 " random misfire " all the time , no specific cyl code , even after replacing the sparks .
but after i replaced the cpas and cps "as advised above from @MRRSM " i can detect specific misfiring codes , and torque pro android app can read misfiring data now ,


good luck in fixing your problem

I replaced the coils and plugs this past weekend and I have not had a code yet. Still have a rough idle but I know that there are some more work to do. Good luck with yours as well.

 

[yazan]

I replaced the coils and plugs this past weekend and I have not had a code yet. Still have a rough idle but I know that there are some more work to do. Good luck with yours as well.

loosen intake bolts ?