Less Power - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Machh5 · 11-25-2020, 03:10 PM

In recent weeks a few things have happened to my 15 LFX. I'm right at 100k miles and started noticing the car has lost power. It starts and runs good but it lost most of its mid range power. No other symptoms I inspected the air filter for leaves, the condition of the throttle body( no carbon build up). I do notice one thing is the high pressure fuel pump sounds noisy. Was quiet before this. Are there tests to check the high pressure fuel pump? The oil is clean no signs of fuel in it. This car has always ran very well so it surprises me its very noticeable. I always run it moderately hard to keep the cats clean and use fuel injection cleaner regularly, nut that long ago the valves were walnut blasted too. They really didn't look bad at all for 87k miles, just a small amount of build up, didn't even change how it runs after cleaning. Only other thing I can come up with is maybe the gas formula has changed with the cold weather. It feels like I put regular fuel in but I always use premium. The car always ran alot better with premium in it.

xstuntman · 11-25-2020, 06:48 PM

Yeah, sudden increase in noise makes me think cavitation and there is a test for line pressure. Me, I'd take it in to get tested and based on what they report back fix it myself.

Not sure about the newer diesels but cavitation happened on the older ones back in the day.

Machh5 · 11-25-2020, 08:33 PM

Thanks for the suggestion, I may just change it out with a new factory part. Till I get it tested it just cheaper to change it. Its got 100k on it, probably time to change it anyway.

Pearlj10 · 11-25-2020, 10:24 PM

Before you change the part out, if you have access to hptuners, or someone who does, you can monitor fuel rail pressure to see if the HPFP is performing or not. Just a thought.

Machh5 · 11-25-2020, 10:33 PM

No I don't but my scanner may be able to see it. I have no idea what it should look like spec wise.

Machh5 · 11-27-2020, 05:08 PM

Running the tank low then refilling with fresh fuel seems to have solved the problem. Although I think the HPFP is a little noisy scanner says the pressure is good. I'll see what happens in the next few tank fills. I've tried to use regular in the past and the car ran terrible with it and thats exactly how its acting. I'm going on a 400 mile trip tomorrow so we'll see how it acts. I do notice something its never done before is at a idle it will miss once or twice then it gone. And not every time you drive it, very randomly. I had a pending code 301 a few months ago but it never turned the light on. I think all these never engines run a little rough cold when they get high mileage on them.

BuddyLee · 11-27-2020, 06:06 PM

The engine is designed for 87 octane. Is that what you consider "regular"?

Machh5 · 11-27-2020, 06:44 PM

It was tuned for premium. Scanner shows 2 fuel readings that read 44-43 PSI but It doesn't tell if its reading the low pressure or high pressure pump pressure. 44 PSI would be normal for the low side and 44 BAR would be normal for the high side. The scanner that reads 2 fuel pressure reading don't match. 1st reading fluctuates between 43-44 second is steady @44. I suspect the scanner is reporting actually reporting bar not PSI as it says. Anyone have a factory manual that could shed some light on this? Car is running good again and all the data looks perfect EXCEPT I can't decode the fuel pressure until I understand what I'm reading. The more advanced scanners I've seen online show high pressure fuel pressure actual and desired. Example will shoe 44bar actual and 44 desired. My 2 scanners only show 2 fuel pressures shown like this fuel pressure(00) 44 and fuel pressure(03) 44. They don't change together, 1 may report 44 while the other 43 and the (00) fluctuates. So I'm just guessing here the the (00) is the high pressure and the (03) is the low pressure. Thanks

xstuntman · 11-27-2020, 07:15 PM

I wouldn't run 87 in mine even if it was free and pumped by swedish bikini models.

xstuntman · 11-27-2020, 07:32 PM

Don't have the material for correct pressure but I am wondering if you saw different pressures from idle and higher rpm.

spyderbuddy · 11-27-2020, 07:46 PM

Mine usually runs up close to 650-795 PSI.
that is fuel rail pressure
it 45 - 80 PSI at the Tank

Machh5 · 11-27-2020, 07:53 PM

I scanned it in the driveway and everything looked spot on. I tried revving it and the fuel reading 1 varies 43-44 when I rev it, fuel reading 2 stays @44 steady. Fuel trims look perfect idle and revving. Driving I can't do here at night because too many deer walking around and I can't see well enough to read it while driving normally. I'm going on a 400 mile trip tomorrow, I'm going to try and watch the fuel trims while under acceleration etc. I may just replace both pumps to be safe. Its @ 99900 and tomorrow it will be 100k plus. Cheap enough to change both pumps after 100k of great service. The car runs ok and it may have just been poor fuel, who knows whats get dumped into the gas tanks today. But its always run excellent before this and I'd miss the performance it has. Very fun to drive with great gas mileage to boot.

Machh5 · 11-27-2020, 07:55 PM

Quote:

Originally Posted by spyderbuddy

Mine usually runs up close to 900 psi or more.

How are you reading it?

Machh5 · 11-27-2020, 08:00 PM

Quote:

Originally Posted by xstuntman

I wouldn't run 87 in mine even if it was free and pumped by swedish bikini models.

This car runs so bad on 87 its just stupid. Almost not driveable, it knock and ping and farts around enough to piss off the Pope.

11-25-2020, 03:10 PM	#1
Machh5 Account Suspended Drives: Camaro Join Date: Jun 2020 Location: US Posts: 120	Less Power In recent weeks a few things have happened to my 15 LFX. I'm right at 100k miles and started noticing the car has lost power. It starts and runs good but it lost most of its mid range power. No other symptoms I inspected the air filter for leaves, the condition of the throttle body( no carbon build up). I do notice one thing is the high pressure fuel pump sounds noisy. Was quiet before this. Are there tests to check the high pressure fuel pump? The oil is clean no signs of fuel in it. This car has always ran very well so it surprises me its very noticeable. I always run it moderately hard to keep the cats clean and use fuel injection cleaner regularly, nut that long ago the valves were walnut blasted too. They really didn't look bad at all for 87k miles, just a small amount of build up, didn't even change how it runs after cleaning. Only other thing I can come up with is maybe the gas formula has changed with the cold weather. It feels like I put regular fuel in but I always use premium. The car always ran alot better with premium in it.

11-25-2020, 06:48 PM	#2
xstuntman Drives: 2012 Victory Red LFX Join Date: Dec 2012 Location: west central Texas Posts: 1,310	Yeah, sudden increase in noise makes me think cavitation and there is a test for line pressure. Me, I'd take it in to get tested and based on what they report back fix it myself. Not sure about the newer diesels but cavitation happened on the older ones back in the day. __________________ 2018 SS wheels, red Heritage grille, actual driving lights, ZL1 strut tower brace, GM Performance billet aluminum fuel door, front grille Bowtie delete, painted red rotors and calipers, 1/4 window American Flags, splash guards, AEM dry panel air filter.

11-27-2020, 07:15 PM	#9
xstuntman Drives: 2012 Victory Red LFX Join Date: Dec 2012 Location: west central Texas Posts: 1,310	I wouldn't run 87 in mine even if it was free and pumped by swedish bikini models. __________________ 2018 SS wheels, red Heritage grille, actual driving lights, ZL1 strut tower brace, GM Performance billet aluminum fuel door, front grille Bowtie delete, painted red rotors and calipers, 1/4 window American Flags, splash guards, AEM dry panel air filter.

11-27-2020, 07:32 PM	#10
xstuntman Drives: 2012 Victory Red LFX Join Date: Dec 2012 Location: west central Texas Posts: 1,310	Don't have the material for correct pressure but I am wondering if you saw different pressures from idle and higher rpm. __________________ 2018 SS wheels, red Heritage grille, actual driving lights, ZL1 strut tower brace, GM Performance billet aluminum fuel door, front grille Bowtie delete, painted red rotors and calipers, 1/4 window American Flags, splash guards, AEM dry panel air filter.

11-27-2020, 07:46 PM	#11
spyderbuddy Drives: 2010 RS Inferno Orange Metallic Join Date: Mar 2010 Location: Albany, Ga. Posts: 3,408 View My Garage	Mine usually runs up close to 650-795 PSI. that is fuel rail pressure it 45 - 80 PSI at the Tank __________________ Hot Wheels Emblems and Floor Mats, Morimoto Fog Lights, PCP Hideaway Headlight Covers, BBK Headers & High Flow Cats, ZL1 Add-ons Wicker Bill, TL1/ZL1 Hood Insert, Gen5 DIY Frameless Mirror, ABL Dash Lighting & My link Navigation, Blacked out Rear Bowtie, all Sylvania led Turn Signals, Ceramic Window Tint By Nicks, MBRP Exhaust tips, GEN5 DIY Virginia Legal DRL Harness, Painted Brake Calipers, Vittesse Throttle Controller & Paddle Shifter Heritage Grill, Manual Shifter Boot, CNC Throttle Body, Trifecta Tune, Trunk Black out and Side Grills, Hot Wheels door Sills. Last edited by spyderbuddy; 11-27-2020 at 08:04 PM.

11-25-2020, 08:33 PM	#3
Machh5 Account Suspended Drives: Camaro Join Date: Jun 2020 Location: US Posts: 120	Thanks for the suggestion, I may just change it out with a new factory part. Till I get it tested it just cheaper to change it. Its got 100k on it, probably time to change it anyway.

11-25-2020, 10:24 PM	#4
Pearlj10 Drives: 2011 Camaro 2LT Join Date: Oct 2018 Location: Az Posts: 367	Before you change the part out, if you have access to hptuners, or someone who does, you can monitor fuel rail pressure to see if the HPFP is performing or not. Just a thought.

11-25-2020, 10:33 PM	#5
Machh5 Account Suspended Drives: Camaro Join Date: Jun 2020 Location: US Posts: 120	No I don't but my scanner may be able to see it. I have no idea what it should look like spec wise.

11-27-2020, 05:08 PM	#6
Machh5 Account Suspended Drives: Camaro Join Date: Jun 2020 Location: US Posts: 120	Running the tank low then refilling with fresh fuel seems to have solved the problem. Although I think the HPFP is a little noisy scanner says the pressure is good. I'll see what happens in the next few tank fills. I've tried to use regular in the past and the car ran terrible with it and thats exactly how its acting. I'm going on a 400 mile trip tomorrow so we'll see how it acts. I do notice something its never done before is at a idle it will miss once or twice then it gone. And not every time you drive it, very randomly. I had a pending code 301 a few months ago but it never turned the light on. I think all these never engines run a little rough cold when they get high mileage on them.

11-27-2020, 06:06 PM	#7
BuddyLee Drives: 2013 Camaro 2SS/RS Join Date: Aug 2020 Location: Pacific Northwest Posts: 802	The engine is designed for 87 octane. Is that what you consider "regular"?

11-27-2020, 06:44 PM	#8
Machh5 Account Suspended Drives: Camaro Join Date: Jun 2020 Location: US Posts: 120	It was tuned for premium. Scanner shows 2 fuel readings that read 44-43 PSI but It doesn't tell if its reading the low pressure or high pressure pump pressure. 44 PSI would be normal for the low side and 44 BAR would be normal for the high side. The scanner that reads 2 fuel pressure reading don't match. 1st reading fluctuates between 43-44 second is steady @44. I suspect the scanner is reporting actually reporting bar not PSI as it says. Anyone have a factory manual that could shed some light on this? Car is running good again and all the data looks perfect EXCEPT I can't decode the fuel pressure until I understand what I'm reading. The more advanced scanners I've seen online show high pressure fuel pressure actual and desired. Example will shoe 44bar actual and 44 desired. My 2 scanners only show 2 fuel pressures shown like this fuel pressure(00) 44 and fuel pressure(03) 44. They don't change together, 1 may report 44 while the other 43 and the (00) fluctuates. So I'm just guessing here the the (00) is the high pressure and the (03) is the low pressure. Thanks

11-27-2020, 07:53 PM	#12
Machh5 Account Suspended Drives: Camaro Join Date: Jun 2020 Location: US Posts: 120	I scanned it in the driveway and everything looked spot on. I tried revving it and the fuel reading 1 varies 43-44 when I rev it, fuel reading 2 stays @44 steady. Fuel trims look perfect idle and revving. Driving I can't do here at night because too many deer walking around and I can't see well enough to read it while driving normally. I'm going on a 400 mile trip tomorrow, I'm going to try and watch the fuel trims while under acceleration etc. I may just replace both pumps to be safe. Its @ 99900 and tomorrow it will be 100k plus. Cheap enough to change both pumps after 100k of great service. The car runs ok and it may have just been poor fuel, who knows whats get dumped into the gas tanks today. But its always run excellent before this and I'd miss the performance it has. Very fun to drive with great gas mileage to boot.