Gen III intake sealing problem
Nov 23, 2015 | 06:47 PM
#1
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From: Conroe, Texas
Gen III intake sealing problem
Just installed my rebuilt 6.0 on my 3/4 ton and it throws a misfire for cylinder one.
The engine is .020 over with dish Pistons, the heads are stock 317s that are milled .040.
I tried today to pull the intake and use RTV in an attempt to solve the intake leak but no success.
When at idle, I have sprayed the intake runner with carb cleaner and the misfires drop down to near zero in EFI live while monitoring the events.
Any help? This is the stock 2004 truck intake.
The engine is .020 over with dish Pistons, the heads are stock 317s that are milled .040.
I tried today to pull the intake and use RTV in an attempt to solve the intake leak but no success.
When at idle, I have sprayed the intake runner with carb cleaner and the misfires drop down to near zero in EFI live while monitoring the events.
Any help? This is the stock 2004 truck intake.
Nov 23, 2015 | 07:28 PM
#4
If you milled the heads, it will in theory widen the plane the intake sits on, or possibly cause the intake to not sit properly on the runners, need ask your machine shop what they recommend..... Really surprised more people havent run into this issue..... Other thing is check your intake for a crack...
Nov 23, 2015 | 07:48 PM
#5
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From: Conroe, Texas
The gel pro actually. Got them new Thursday before installing the intake Friday.
Has a GM hotcam. We deactivated the misfire below 1000 RPM and we pick up misfire on cylinder one and eight. So one seems to be the problem. When I was tightening the intake more or spraying it with carb cleaner the misfire would nearly disappear.
It is the same intake that came off the truck before swapping the engine. I will check it again the next time it is off.
Has a GM hotcam. We deactivated the misfire below 1000 RPM and we pick up misfire on cylinder one and eight. So one seems to be the problem. When I was tightening the intake more or spraying it with carb cleaner the misfire would nearly disappear.
If you milled the heads, it will in theory widen the plane the intake sits on, or possibly cause the intake to not sit properly on the runners, need ask your machine shop what they recommend..... Really surprised more people havent run into this issue..... Other thing is check your intake for a crack...
Nov 23, 2015 | 08:04 PM
#6
You can try increasing the misfire disable to 1500 rpm
Also, I dont understand why spraying carb cleaner would clear the misfire. Is the engine sound actually changing when you spray the cleaner indicating an actual leak? My heads are milled a similar amount with stock manifold and no leak
Also, I dont understand why spraying carb cleaner would clear the misfire. Is the engine sound actually changing when you spray the cleaner indicating an actual leak? My heads are milled a similar amount with stock manifold and no leak
Nov 23, 2015 | 08:26 PM
#7
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It is enough that the misfire is lowering to near none at all on EFI love when I spray the cleaner there. We will be busting *** on it tomorrow I'm sure but I'm out of ideas. It is running like **** now in the RPM.