Low engine power?

Welcome to 2CarPros.

Anytime a catalytic converter is partially plugged, it can cause power loss. Have you tried removing the O2 sensors to see if that is the possible issue? Take a look through this link.

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

As far as the crankshaft position sensor relearn, anytime an engine is replaced, it has to be done. And yes, that could be part of the problem.

Here are the directions:

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CRANKSHAFT POSITION SYSTEM VARIATION LEARN
Crankshaft Position System Variation Learn

Note: The Crankshaft Position System Variation Learn procedure is also required when the following service procedures have been performed, regardless of whether DTC P0315 is set:

* An engine replacement

* A engine control module (ECM) replacement

* A crankshaft balancer replacement

* A crankshaft replacement

* A crankshaft position sensor replacement

* Any engine repairs which disturb the crankshaft to crankshaft position sensor relationship.

Note: The ECM monitors certain component signals to determine if all the conditions are met to continue with the crankshaft position System Variation Learn Procedure. The scan tool only displays the condition that inhibits the procedure. The scan tool displays the signals of the following components:

* Crankshaft position sensors activity-If there is a crankshaft position sensor condition, refer to the applicable DTC that set.

* Camshaft position sensor signal activity-If there is a camshaft position sensor signal condition, refer to the applicable DTC that set.

* Engine coolant temperature (ECT)-If the engine coolant temperature is not warm enough, idle the engine until the engine coolant temperature reaches the correct temperature.

1. Install a scan tool.

2. Monitor the ECM for DTCs with a scan tool. If other DTCs are set, except DTC P0315, refer to Diagnostic Trouble Code (DTC) List - Vehicle See: A L L Diagnostic Trouble Codes ( DTC ) > Diagnostic Trouble Code Descriptions > Diagnostic Trouble Code (DTC) List - Vehicle for the applicable DTC that set.

3. With a scan tool, select the Crankshaft Position System Variation Learn Procedure and perform the following:

1. Block drive wheels.

2. Set parking brake.

3. DO NOT apply brake pedal.

4. Cycle ignition from OFF to ON.

5. Apply and hold brake pedal for the duration of the procedure.

6. Start and idle engine.

7. Turn the air conditioning (A/C) OFF.

8. The vehicle must remain in Park or Neutral.

Note: While the learn procedure is in progress, release the throttle immediately when the engine starts to decelerate. The engine control is returned to the operator and the engine responds to throttle position after the learn procedure is complete.

9. Accelerate to wide open throttle (WOT) and release when the fuel cut-off occurs.

4. The scan tool displays Learn Status: Learned this Ignition. If the scan tool indicates that DTC P0315 ran and passed, the crankshaft position variation learn procedure is complete. If the scan tool indicates DTC P0315 failed or did not run, or another DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle See: A L L Diagnostic Trouble Codes ( DTC ) > Diagnostic Trouble Code Descriptions > Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.

5. Once the learn procedure has successfully completed, and in order to store the crankshaft position system variation values in the ECM, turn OFF the ignition and verify all vehicle systems are OFF. This may take up to two minutes.
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Try that and let me know if it helps.

Joe

Okay, I will let you know about relearn. the dealer did replace both bank 1 and 2 converters! I was playing with it tonight watching the live data on code reader an noticed the ignition advance at idle was 1.4 then at 2500 it was 53 degrees not sure about normal specs are supposed to be.

Let me know what you find. As far as the timing, that's not unexpected. Also, since you have a live data scanner, can you let me know what the fuel trims are running at, both short and long term?

Take care and I'll watch for your reply.

Joe

Okay update; dealer finally got to it and found the third catalytic converter was plugged. They did the relearn and tech 2 said it passed the test. Going to get it now Finger crossed, Thanks!

Welcome back:

That's it. The P0420 indicated a faulty converter. I'm glad to hear they got it figured for you. I'll keep my fingers crossed for you. Let me know how it's running.

Take care,
Joe

It's fixed, finally! Now one more question. the engine I installed has been sitting in the salvage yards building since late 2012. Should I do anything with the seals on the fuel injectors? I did need to replace the high pressure fuel pump due to it leaking.

Hi WILLPAT100,

Thank you for using 2CarPros. Can you please start a new question? The question you are asking is about a different issue. In order for the site to properly index your question it needs to be its own question. I have included the link. Please make sure you logged into the site before clicking on the link.

https://www.2carpros.com/questions/new

Have a great weekend!

Renee
Admin

Not a problem, thank you to all who helped me, this site is great!!

Happy to help.

Take care,
Joe

i have a 2009 chevy impla and my traction control came one and my car wont go over 40 mph. can you give me some pointers

It sounds like the car is in limp in mode with means there is an issue with the transmission/engine traction control. This guide can help us fix it

https://www.2carpros.com/articles/engine-has-low-power-output

Please run down this guide and report back.

When driving down road usually about 40 mph. With my gas pedal in same position my car will slow down and speed up a couple times for no reason. But doesn’t do it every time.

Hi,

That sounds like a fuel pump issue. Has the check engine light been staying on when the engine is running? If it is, the next step is to get the computer scanned for diagnostic trouble codes. Here is a quick video showing how it's done:

https://youtu.be/YV3TRZwer8k

I realize most people don't own a scanner, but often times a parts store will do it free of charge. So, if the light is staying on, have that done and let me know what codes are found.

Now, if the light isn't on, then we need to move to the next thing, fuel pressure. Here is a link that shows how to check it:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Here are the manufacturer's specs for pressure:

Fuel Pressure (Key ON, Engine OFF) .................... 384-425 kPa (56-62 psi)

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Let me know what you find or if you have questions.

Take care,
Joe

Engine light is not on.

Hi,

Okay, then we need to check fuel pressure. Low fuel pressure can cause what you described. Let me know if you need help or have questions.

Take care,
Joe

Do you think this could be the transmission. If so how will I know that.

Hi,

I doubt it is the transmission. If the transmission was causing this, chances are the engine RPM's would increase when it slows down indicating slippage.

My girlfriend says that this is usually happens about 20 mph and when it happens the rpm's do jump from little over one to 2 then back down.

Hi,

If the RPM's are increasing but the vehicle slows down, then it does sound like it could be transmission related and is slipping. Have you checked the transmission fluid level and condition? If you look at pics 1 and 2, it explains what to do.

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Let me know.

Joe

Hello, I just finished repairing the wire attached to the camshaft position actuator solenoid. The serpentine belt had chewed through it, that is what causes my engine light to come on. After fixing the problem, the engine light when out on it on.

I have replaced the spark plugs, throttle body, mass air flow sensor, o2 sensors, and air filters. Most were due for change/replacing.

Changing the above mention item, I knew the car had to relearn some of the parts; Evap, secondary air, oxygen sensor monitor, and oxygen sensor heater.

However, when driving to get on the highway, before getting to the highway, I had to go up the hill (thirty degree climb). While going up the hill the car started to shutter and it stops accelerating. I continue my journey to get to the highway to complete the calibration of the mention components. Did not make it because the car just stops accelerating. the only way it would accelerate, for about three seconds interval, is when I press on the gas and take my foot off it fast. I just came back home.

When pressing the gas I can hear the motor drawing loud and I can see the tachometer gauge hand moving, but the car would not accelerate.

I have no trouble with the car start. Put the key in, it starts up. No hesitation or any things. No trouble codes.

Last time timing belt was changed? Two months ago
Last time spark plugs were changed? Two weeks
Last time fuel filter was changed? Have not.
Last time air filter was changed? Two weeks ago.
Are there any error codes? No code on ODB11.
Last time EGR valve was cleaned? Never.
Last time EGR passageways were cleaned? Never.
Last time throttle body was cleaned? New replace six days ago. email date.
Last time IAC was cleaned? Not sure of this one. Never for me.

I was thinking it could be the transmission, however, when I park it, transmission was working fine. Check oil and transmission fluid, are all fine. Transmission serviced about sixteen months ago.

Thank very much for giving this your attention.

Hello,

It sounds like you have a plugged catalytic converter. Here is a guide that will help you confirm the problem:

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

and

https://www.2carpros.com/articles/bad-catalytic-converter-symptoms

and

https://www.2carpros.com/articles/catalytic-converter-replacement

Please let us know what happens.

Cheers, Ken

Car spits and sputters. The check engine light on flashing. smells gas bad like rotten eggs. white smoke out of tail pipe. Not running hot only half way temperature. check engine light went off for a few days an ran perfect then light came back on and it has no power. press gas to floor and it bogs down. I am stumped.

Flashing light indicates a severe misfire. Scan the vehicle for codes to see if there are any other codes besides the misfire codes that may pop up. Post the codes on here and lets try to figure this out.

Also, the rotten egg smell is likely from a clogged catalytic converter. Again, get the codes scanned. If the converter is clogged, you will likely get a P0420 code, in addition to any other codes that pop up. Your local AutoZone, Advance Auto, or O'reilly auto parts stores will scan it for you for free.

Hi MIKES1967,

If you decide you would like to conduct the scan yourself here is a link to an article that features written step by step instructions and pictures explaining how to do the scan yourself. Also, I have included a link to our YouTube channel with a how to video on code scanning.

This is applicable even if your check engine light is not on.

Most scanners are inexpensive to purchase, you can purchase one online from sites like Amazon.com

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

https://youtu.be/YV3TRZwer8k

Once you have the codes please get back to us so that we can further assist you. We are always happy to help.

Thank you for visiting 2CarPros.com.

Kindest regards,

Renee
Admin

Ok so I've been battling this problem for a while to no avail:
My 07 impala 3.5 flex is making valve train noise after replacing intake manifold gasket, and replacing plugs and wires I've been told it may have something to do with pushrods and or hydraulic lifters here's my testing so far

Compression
1-198
2-202
3-195
4-203
5-201
6-200

Fuel pressure-
steady 58 psi running holds 50psi after key off
Fpr- operates fine

Vacuum-
Cranking 5"hg
Idle- 19 average but constantly fluctuates/flutter 3-4"hg
Snap throttle-0 and 25"hg high back to 19"hg slowly with a erratic fluctuation
1000rpm-20"hg pretty steady
2500rpm-22"hg

Good spark
Ac delco iridiums
Plugs gapped at 0.040"
Clean filter

Car has a weird loping feel at idle (very slight)
Can here constant ticking in car at idle
Idle is normally at 750-800rpm but intermittently it will drop about 100rpm or so when brakes are applied, and the engine begins to lope
I experience very inconsistent acceleration, loosing speed up hills
Doesn't want to hold rpms cruising in 2 or 3

The tranny isn't in the greatest condition but it has driven pretty much since the day I got it, and my problems got way worse after the manifold gasket replacement which is why I'm thinking valve train issues

Any insight would be appreciated

if you didn't have any problems until the intake gasket replacement then recheck your work or who ever did it. the pushrods are different lengths so could be int eh wrong positions as well as the gasket could be binding a pushrod. your compression looks ok as high to low is only 8 # difference. maybe the pushrods aren't adjusted correctly either.

Well see that's where I'm stumped I personaly did the intake gasket, all pushrods in correct order, no wear on the gasket the first time I did it, second time I checked everything over againand i couldn't notice anything wrong, only thing I noticed was that the number 2 Pushrod looked a little stressed maybe bent very very slightly, but I don't see how that would cause such a lack in power, and its not missing.

I also don't think it has to do with the pushrods necessarily bc I have driven about 4000 miles on it like it is

Any other ideas?

Also the rpms will jump when I LET OFF the gas cruising at like 45.
I just want to eliminate some possibilitys
A collapsed lifter would be noted in a loss off compression correct?
And if the Pushrod was indeed bent wouldn't it missfire?
Is there any way a rocker arm pedestal could be installed the wrong way?

I mean jump as in 200-400 rpm once and then it decelerates as it should

scan for codes, check fuel pressure and clean throttle plate on both sides with choke cleaner. then check for a vacuum leak with choke cleaner. also clean iac valve and make sure duct work has no holes in it and connected to throttle body.

No codes, fuel pressure at 58 steady, and fuel pressure responds as it should on acceleration, throttle plate cleaned alreAdy, and there is no iacv on this car, its a drive by wire so the throttle body is electric, and tps/iac are basically one unit

First off I'm sorry for asking a bunch of questions on this car I just want it fixed so I can get rid of it.

Before the intake it was running funny, hesitating on take off and hesitating on accel, I tore it down after it started leaking coolant from the crossover.

After I replaced the intake and plugs/wires the car started funny and was noisy on startup, the valve train started making more noise then before and my power loss/ hesitation became worse

Basically my question is...
Could this be an out of place Pushrod?
Could I even drive 5k if I did misplaced a Pushrod?
Lifter issue?
Or a clogged cat?

I ask this bc all I have tested so far came out good except manifold vacuum
Compression 200 -/+ 5 all 6
Fuel pressure 58 to about 60 on accel
Spark strong
Fuel Injectors all working
Air filter new
Maf/map good
Coolant/iat good
Throttle clean
Plugs(ac delco .040)

Only thing standing out is vacuum fluctuates 2-4 at idle but OS pretty steady at 19

Any ones knowledge on this homogulation of the 3.4 please help me out, I'm stuck between a rock and a hard place I would tare into it again but I want to be 110% sure of what I need to fix

Thanks again

I also searched everywhere for a vacuum leak to no avail, the ST AND LT fuel trims don't show any evidence of any cylinder(s) running lean due to a vacuum leak

lifters stick after this repair and i always recommend replacing them with this repair. it most likely is part of your issue.

as far as the push rods, no, you are good. if you messed them up, you would have bent a valve and had many other issues and no compression.

the vacuum fluctuation concerns me. you may have a valve not seating or burned.

i would start with the lifters.

Roy

without hearing this car it can only seem like a lifter problem. Maybe one is collapsing , and it seems to me like apushrod problem. the intake pushrods should have yellow stripes and exaust should have blue stripes.or the intakes shold be 5.81 in long andexaust 6.1 in long. also the rocker carms should have been torqued to 25 ft. lb. as that is the adjustment. i'd recheck it once more to make sure they are right and torqued right.

Couldnt that fluctuation be from the lifters sticking? And I take it if a valve got burned it was most likely due to the lifters sticking?

And can you explain a good prep for installing the lifters?

one other thing, because of the valve clatter it is probably making your knock sensor go off and it's retarding the timing causing your low power.

yes, the lifters could cause it.

soak them in oil before installing.

Roy