LS3 - 495 seems to be spitting fuel all over the back of my car

[69camarokid]

Hello Awesome People!

I recently installed an LS376-495 with TR6060 into my 69 Camaro. I absolutely love the engine in my car, but i have noticed that since this was installed I
keep getting fuel (I think) all over the entire rear end of the car. I clean/wash her, take her for a ride, and shes immediately covered again.
Is this because of the hot cam that comes with this engine? Just trying to see if anyone knows why this would happen and if there is anything I can do to stop it, or at least cut it down.
Any thoughts or ideas are appreciated. Thanks.
175284

[69camarokid]

Bump on this thread to try to find out why Im getting so much unburnt fuel on the back of my car.

Any thoughts are welcome. Thanks.

[dhutton]

How did you set up your crankcase ventilation?

Don

[raustinss]

I'd agree on the pcv system also what is the setup for venting of the gas tank

[Gmachine1911]

I’m running the LS3/525 and prior to taking it to the tuner, mine also ran rich and would leave a residue on the rear bumper/tail panel area. I’m sure GM sets the ECM’s to run rich for protection. Even out of the gate, although I knew it was running rich, I felt it ran strong. After having it tuned, it gained 75HP to the rear wheels and made a huge difference...plus no more residue. If you haven’t had it tuned, it might be worth a shot, provided it’s fuel and not oil residue.

[69camarokid]

You gained 75 to the rear wheels!?!! From just the tune!? God Damn! Thats impressive.

I have LS376-495 and other than medium length headers, everything has been completely stock since I purchased the engine.

Any particular style of tune you got? My carmaro gets around 13 mpg, which even with the cam I would assume seems low for an LS3. I assume it is running rich due to the gas coming out the rear. I can stand behind it and feel moisture hitting my legs when it is running.

Was there anything specific you requested with or for your tune? I use the car as a daily driver and a few track days each year.

Thanks.

[badazz81z28]

So I'm lost here....Are you saying gas is coming out of the exhaust? Can you physically see it coming out of the exhaust while it sits? What kind of tank are you running? Have you checked the fuel tank to ensure there are no leaks? This is not normal regardless of the type of cam you have. For gas to come out of the exhaust and be on the tail of the car up by the lights? I don't see it...

[69camarokid]

So I'm lost here....Are you saying gas is coming out of the exhaust? Can you physically see it coming out of the exhaust while it sits? What kind of tank are you running? Have you checked the fuel tank to ensure there are no leaks? This is not normal regardless of the type of cam you have. For gas to come out of the exhaust and be on the tail of the car up by the lights? I don't see it...

I could very well be wrong about what is actually happening. What I do know is that liquid is coming out of my exhaust, enough to feel like a light sputtering of liquid.
I am not sure that it is gas at all, that was my best guess. What I do know is that when driving something is coming out of the back and covering my entire rear, from the lowest level to the top of the spoiler, with a liquid that is definitley not water, and that I believe to be gas. It could very well be something else. Its viscosity is similar to water, but it is a bit more slimy upon touching it.

Thoughts?

[raustinss]

Maybe I'm wrong but could it not be condesation from the exhaust mixed with the exhaust ? Also have you driven the car for a good 15 mins is the problem still there

[69camarokid]

How did you set up your crankcase ventilation?

Don

I have no clue. This engine was bought straight from GM and dropped in by my local shop.

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Maybe I'm wrong but could it not be condesation from the exhaust mixed with the exhaust ? Also have you driven the car for a good 15 mins is the problem still there

Suppose it could be. This has happened every time I drive the car. LASt week I washed her and then drove her for about 45 minutes and when I came back the entire back was covered.

[eville]

Any chance it’s oil?

[dhutton]

Any chance it’s oil?
Yes that’s why I asked about crankcase ventilation. A more likely suspect imho...

Don

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I have no clue. This engine was bought straight from GM and dropped in by my local shop.

You probably need to get a clue imho. This is important and if it’s not done right it can make a real mess....

Don

[65 drop top]

How did you set up your crankcase ventilation?

Don
For future reference, what is the proper way to vent the crankcase?

[dhutton]

For future reference, what is the proper way to vent the crankcase?
It’s in the GMPP instructions. Draw fresh air from the intake between the MAF and throttle body then connected to one of the valve covers. The crankcase to throttle body connection is made with a factory flex hose on GMPP crate engines. If you add a catchcan it is connected to replace the flex hose.

Don

[icemanrd19]

Most like it’s your tank vent. Show us pictures of that setup.

As far as the pcv the drivers side valve cover is capped, passenger cover runs to the intake tube in between the throttle body and maf.

Not fuel related but if you Alamo
Want to run a oil catch can the line from the valley cover and throttle body is what you need. Valley cover into the oil catch can, catch can into the intake where the u shaped hose use to be connected.

[69camarokid]

It’s in the GMPP instructions. Draw fresh air from the intake between the MAF and throttle body then connected to one of the valve covers. The crankcase to throttle body connection is made with a factory flex hose on GMPP crate engines. If you add a catchcan it is connected to replace the flex hose.

Don

I do not seem to have any additional intake lines running from between the MAF and the throttle body to the valve cover. The only thing I did see is this small air filter attached to the front of my passenger side valve cover. I believe this is the crankcase ventilation.

Am i right?

175527

[69camarokid]

Most like it’s your tank vent. Show us pictures of that setup.



The gas tank is a Holly EFI tank (part#19-404) adn the vent is run up form the back of the tank and attached on the passenger side just above the rear mounting point for the leaf spring. Ive attached a picture below.

Please let me know your thoughts.
175528

[dhutton]

That is not the correct way to vent the crankcase. It should be done as I described. You are burning unmetered air the way it is configured.

That is a Mickey Mouse way to vent a tank. I wouldn’t be surprised if it is puking fuel. Get a iimuch vent and install it higher. Usually in the trunk with the filter plumbed outside.

Don

[XLexusTech]

I agree Don CCV is critical an an open air vent wont get it done.. is their a port typically used for this on an Ls?

I found this.. if it helps anyone..

http://www.4x4-16.com/LS3-PCV-help_10852391.html

PS to the OP.. not to be a keyboard critic.. Bt that heater hose bypass zip tied to the intake rail is driving me nuts..
Here is a more subtle solution..
https://www.amazon.com/Heater-Bypass-Coolant-Crossover-551699/dp/B013QNJ9SQ

[Gmachine1911]

Yeah, you should definitely replumb the CCV system, otherwise you’re doing yourself and your nice, expensive crate engine a disservice. Here’s how mine is plumbed. I’m using Mike Norris’ setup. I liked the fact that it wasn’t crazy expensive and bolted nice and neat to the passenger side head. I will tell you that last year on HRPT, the hose going to the valley cover swelled slightly creating a vacuum leak which made the check engine light come on. Car ran fine but the hose was very loose so I put a zip tie around it which fixed it instantly...just never changed it so something to watch for. I empty the catch can at every oil change via the drain petcock in the bottom but never get a ton of oil. You need one to keep from recirculating engine oil and unburned gases thru your throttle body (asthe factory designed) which will gum things up over time while still venting the system properly. I think I bought mine from Scoggin Dickey...175559175560175561

[dhutton]

I agree Don CCV is critical an an open air vent wont get it done.. is their a port typically used for this on an Ls?

I found this.. if it helps anyone..

http://www.4x4-16.com/LS3-PCV-help_10852391.html

PS to the OP.. not to be a keyboard critic.. Bt that heater hose bypass zip tied to the intake rail is driving me nuts..
Here is a more subtle solution..
https://www.amazon.com/Heater-Bypass-Coolant-Crossover-551699/dp/B013QNJ9SQ

On a GMPP crate engine you just need to connect the valve cover to a fitting installed in the intake tube between the MAF and throttle body. This insures the fresh air is metered. If you want to add a catch can you install it where the corrugated tube runs between the valley cover and throttle body.

Don

[icemanrd19]

remove that filter and run the line between the throttle
body and maf.


I do not seem to have any additional intake lines running from between the MAF and the throttle body to the valve cover. The only thing I did see is this small air filter attached to the front of my passenger side valve cover. I believe this is the crankcase ventilation.

Am i right?

175527

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exactly


That is not the correct way to vent the crankcase. It should be done as I described. You are burning unmetered air the way it is configured.

That is a Mickey Mouse way to vent a tank. I wouldn’t be surprised if it is puking fuel. Get a iimuch vent and install it higher. Usually in the trunk with the filter plumbed outside.

Don

- - - Updated - - -

this is the correct way for the catch can but the valve cover should run to the intake



Yeah, you should definitely replumb the CCV system, otherwise you’re doing yourself and your nice, expensive crate engine a disservice. Here’s how mine is plumbed. I’m using Mike Norris’ setup. I liked the fact that it wasn’t crazy expensive and bolted nice and neat to the passenger side head. I will tell you that last year on HRPT, the hose going to the valley cover swelled slightly creating a vacuum leak which made the check engine light come on. Car ran fine but the hose was very loose so I put a zip tie around it which fixed it instantly...just never changed it so something to watch for. I empty the catch can at every oil change via the drain petcock in the bottom but never get a ton of oil. You need one to keep from recirculating engine oil and unburned gases thru your throttle body (asthe factory designed) which will gum things up over time while still venting the system properly. I think I bought mine from Scoggin Dickey...175559175560175561

[XLexusTech]

Yeah, you should definitely replumb the CCV system, otherwise you’re doing yourself and your nice, expensive crate engine a disservice. Here’s how mine is plumbed. I’m using Mike Norris’ setup. I liked the fact that it wasn’t crazy expensive and bolted nice and neat to the passenger side head. I will tell you that last year on HRPT, the hose going to the valley cover swelled slightly creating a vacuum leak which made the check engine light come on. Car ran fine but the hose was very loose so I put a zip tie around it which fixed it instantly...just never changed it so something to watch for. I empty the catch can at every oil change via the drain petcock in the bottom but never get a ton of oil. You need one to keep from recirculating engine oil and unburned gases thru your throttle body (asthe factory designed) which will gum things up over time while still venting the system properly. I think I bought mine from Scoggin Dickey...175559175560175561


Thank you shane. looks like you have my same valve covers and front runner system... does the can come with a routing digram you can post? Any pics from the AC Compressor POV of the can?

[dhutton]

remove that filter and run the line between the throttle
body and maf.



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exactly



- - - Updated - - -

this is the correct way for the catch can but the valve cover should run to the intake
Pretty sure that is what I said. Valve cover to intake between MAF and throttle body....

Don

[XLexusTech]

Pretty sure that is what I said. Valve cover to intake between MAF and throttle body....

Don


Let me make sure I am reading this correctly... which is correct.. ?

Left valve cover connected to right valve cover via Y fitting then connected to fitting in fresh air intake which is after MAF and before Valve body.. (no valving what soever)

OR

Left valve cover connected to right valve cover via Y fitting then connected to an inline PCV Like this one..
https://shop.advanceautoparts.com/p/beck-arnley-pac-valve-045-0299/18026363-P?utm_medium=affiliate&c3nid=IR-27795&utm_source=ir&c3ch=Affiliate&clickid=STCWQ7UY6xyOUohwUx0Mo38QUkizlqXQEz%3Aqy00&utm_campaign=27795&utm_content=404718&irgwc=1

Then to connected to fitting in fresh air intake which is after MAF and before Valve body. ?

Or last..
A catch can setup .. ( I wont get into that option.)

[69camarokid]

I agree Don CCV is critical an an open air vent wont get it done.. is their a port typically used for this on an Ls?

I found this.. if it helps anyone..

http://www.4x4-16.com/LS3-PCV-help_10852391.html

PS to the OP.. not to be a keyboard critic.. Bt that heater hose bypass zip tied to the intake rail is driving me nuts..
Here is a more subtle solution..
https://www.amazon.com/Heater-Bypass-Coolant-Crossover-551699/dp/B013QNJ9SQ

No problem at all my friend. I appreciate the input.
I also hate the way the bypass looks but had trouble finding a better short term solution. The product you linked is exactly what I need. I appreciate the help and advice.

Ill be checking out and reading through your link later tonight regarding the catch can. Thanks!

[Gmachine1911]

Here’s a view from the front. Also, the instructions that come with the Mike Norris catch can kit.

[dhutton]

Let me make sure I am reading this correctly... which is correct.. ?

Left valve cover connected to right valve cover via Y fitting then connected to fitting in fresh air intake which is after MAF and before Valve body.. (no valving what soever)

OR

Left valve cover connected to right valve cover via Y fitting then connected to an inline PCV Like this one..
https://shop.advanceautoparts.com/p/beck-arnley-pac-valve-045-0299/18026363-P?utm_medium=affiliate&c3nid=IR-27795&utm_source=ir&c3ch=Affiliate&clickid=STCWQ7UY6xyOUohwUx0Mo38QUkizlqXQEz%3Aqy00&utm_campaign=27795&utm_content=404718&irgwc=1

Then to connected to fitting in fresh air intake which is after MAF and before Valve body. ?

Or last..
A catch can setup .. ( I wont get into that option.)
What I posted was for factory valve covers which have small metering tubes which replace the PCV.

If you are using aftermarket covers without the metering tubes then yes you may need a PCV.

[XLexusTech]

What I posted was for factory valve covers which have small metering tubes which replace the PCV.

If you are using aftermarket covers without the metering tubes then yes you may need a PCV.

For Holly Valve covers

"

Some applications have internal PCV restrictions inside the cover assembly. If your application utilizes this type of connection, an external PCV valve must be added in-line on the hose.

[XLexusTech]

OK so now three days into research on this.. sounds like most people prefer a catch can. I want to avoid that if possible but will do it if I have to.

Given Ls3 N/A moror
Given Holley Angled coil valve covers with non metered tubes.

Drivers side VC tube >>Inline PCV (Beck Arnley 045-0299 inline PCV) to valley cover. Pass side valve cover tube to air intake tube after MAF.

OR
Drivers side VC tube >> to valley cover. Pass side valve cover Inline PCV (Beck Arnley 045-0299 inline PCV) tube to air intake tube after MAF.

[icemanrd19]

For the love of god stop over thinking this. Lol

Passenger valve cover to the intake between throttle body and maf

Cap the drivers side

Leave the valley plate to intake line alone or if you want add a catch can which I highly suggest. Your intake will thank you.

[XLexusTech]

For the love of god stop over thinking this. Lol

Passenger valve cover to the intake between throttle body and maf

(with an inline pcv or no?) read all over the web that the Holly covers cause problems. cause the tubes are unmetered.

Cap the drivers side

Leave the valley plate to intake line alone or if you want add a catch can which I highly suggest. Your intake will thank you.

Got it .. sealed or vented..

PS I read so many horror stories.. I guess my paranoia is in full tilt..

[icemanrd19]

Simple cheap catch can setup will work. If you wanted to upgrade in the future you could go with a Mighty Mouse vented setup if switching to boost. A normal cheap setup will work. I had a elite engineering can before. Worked great.

[XLexusTech]

Simple cheap catch can setup will work. If you wanted to upgrade in the future you could go with a Mighty Mouse vented setup if switching to boost. A normal cheap setup will work. I had a elite engineering can before. Worked great.

Screw it.. going to just buy the Mightly mouse can and call it a day.... Tired of thinking about it LOL

so that looks like... Pass valve cover to Mighty mouse can.. then Can to port in air intake behind MAF.. then Cap drivers cover. with no need for inline PCV..

I think eventually I will end up with boost.. so this is my fck it do it once approach.

[dhutton]

Screw it.. going to just buy the Mightly mouse can and call it a day.... Tired of thinking about it LOL

so that looks like... Pass valve cover to Mighty mouse can.. then Can to port in air intake behind MAF.. then Cap drivers cover. with no need for inline PCV..

I think eventually I will end up with boost.. so this is my fck it do it once approach.
So you’re putting the can on the clean side? That’s a complete mystery to me....

Don

[XLexusTech]

So you’re putting the can on the clean side? That’s a complete mystery to me....

Don

IS there a "Clean side" when you use Holley Valve covers? As I understand it.. the Holley covers are not metered and unless your saying their is an physical connection via port .. between the valley pan and the Drivers side cover.. I am not sure their is a clean side .. just two valve covers each with a port..

Or are you saying the catch can has no business in the clean air inlet at all .. just dump gasses in can. if so I am with you just need the right source for Vacum.. to "pull" the gasses from the Valve cover
If thats not the air inlet.. I am all ears to a suggestion. throttle body maybe?

[dhutton]

Clean side is from intake tube to valve cover. Dirty side is from valley pan to throttle body. Put the can in the dirty side as is usually done. With those valve covers you can install a PCV valve.

Don

[dhutton]

The connection from valley pan to throttle body is already done for you with a GMPP crate engine. It’s the corrugated tube you can see on the passenger side. This is the vacuum....

Don

[dhutton]

Here’s a good pic showing the catch can plumbed into the valley pan replacing the corrugated tube.

Don

[raustinss]

90 percent sure DSE didnt build ls3velle... he builds all his other cars .

[dhutton]

90 percent sure DSE didnt build ls3velle... he builds all his other cars .
Ok my mistake. DSE posted it on Instagram. Still valid for illustration purposes....

don

[69camarokid]

Road race catch can is on its way from Mighty Mouse Catch Cans. Ordering a II MUch vent system form the fuel tank (damn these guys are not cheap, but damn they look good)

Hopefully these upgrades will keep my engine nice and happy for the foreseeable future.

Thanks for the insight everyone. Much appreciated!