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Old 04-23-2014   #141
XfireZ51
 
Join Date: May 2007
Location: Chicagoland, IL
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Default Re: My last effort

Quote:
Originally Posted by LGAFF View Post
This car has Jeal cams which have ramps that open quicker than even regrinds...meaning overlap, less vac...confusing the MAP Sensor and O2s...meaning its going to run pig rich more than likely.....if you did not program the chip for the cams...there are going to be idle and fuel issues.
The O2s present an issue only if he's running Closed Loop. The MAP sensor won't be confused but it will move around a bit causing fuel and spark to change constantly.If the VE and SA tables aren't "smoothed", the motor will bounce around, ie surge as the cal moves from one cell to the other.
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Old 04-23-2014   #142
Hib Halverson
 
Join Date: Jun 2005
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Default Re: My last effort

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Originally Posted by XfireZ51 View Post
Jeff,

No such param in the cal. Certain it's Hib being snarky.
"Snarky"?
Ok. You guys caught me snarkified.

Actually, the post about the oil vapor inversion initiator valve was supposed to be a joke but, since the first part of the text was "moderated", the effect was not as desired. Maybe I should made the post three weeks ago and called it an "oil vapor inversion inebriator valve" to make the humor more obvious.

I just was having a little fun...maybe out of frustration with how difficult this site has become to enjoy with the aggressive stance its owners have chosen in moderating its content.

As for the engine which was smoking, had high oil use but "cleaned up" after the cal was changed.

I've never head of a case of cylinder wall wash down due to an excessively rich mixture which was to the extent described but without terrible drivability and the MIL coming on. Nevertheless, if the problem went away with a cal change, that's great news. Unfortunately, that bad a case of gasoline dilution of the oil usually causes bore wear. Sounds like it didn't go on for too long so hopefully there's no long lasting damage.

I'd change the oil and filter immediately.
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Old 04-23-2014   #143
LGAFF
 
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Default Re: My last effort

Quote:
Originally Posted by XfireZ51 View Post
The O2s present an issue only if he's running Closed Loop. The MAP sensor won't be confused but it will move around a bit causing fuel and spark to change constantly.If the VE and SA tables aren't "smoothed", the motor will bounce around, ie surge as the cal moves from one cell to the other.
So are you saying that a cammed car does not need to caibrated then vs a chip for a ported car? I think we would both agree that is not the case.

They actually make a MAP signal dampner for cars with extremely large cams
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Old 04-23-2014   #144
Schrade
 
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Default Re: My last effort

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Originally Posted by scottfab View Post
I have an early production 90.
As I remember, it has a two wire connection down there.
I remember wondering what it was.
I wonder. I do know that no matter how long I have the car
I keep learning stuff. It's only those that think they have all
the answers that get in trouble. They cannot be educated.
That' the difference between 'know-it-alls', and wise men
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( :thumbsup: [b]and to think I complied with a mod's request to delete a pic of him in a Challenge Car in NCM Museum, so he wouldn't get in hot water)[/b]

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Old 04-23-2014   #145
XfireZ51
 
Join Date: May 2007
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Default Re: My last effort

Quote:
Originally Posted by LGAFF View Post
So are you saying that a cammed car does not need to caibrated then vs a chip for a ported car? I think we would both agree that is not the case.

They actually make a MAP signal dampner for cars with extremely large cams
No that's not what I am saying. You still need to tune the VE tables whether its open or closed loop. In fact, you could start w a base VE using a WB, then move on to Closed Loop. My comment was to clarify that the O2s come into play when you are running closed loop. I suspect the Jeal cams are not so radical that you would need to run N-alpha mode(N-Alpha is to remove somewhat the MAP sensor's contribution from engine fueling, used only when true MAP readings are not usable.). I believe Todd may be using that for his 427 given the spec of his cams. Not sure if its being used just at idle or other parts.
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Old 04-23-2014   #146
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Default Re: My last effort

Quote:
Originally Posted by scottfab View Post
I have an early production 90.
As I remember, it has a two wire connection down there.
I remember wondering what it was.
I wonder. I do know that no matter how long I have the car
I keep learning stuff. It's only those that think they have all
the answers that get in trouble. They cannot be educated.
Dang. Should have kept it going Hib.
And yes, a few weeks back (say April 1st) would have been better.=D>
I guess I'll have to tuck those wires back in
If you can't educate them you can pull their chain.
The last time this was pulled was on the list server.
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Old 04-23-2014   #147
XfireZ51
 
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Default Re: My last effort

Seriously tho Hib, with your journalistic prowess, why not determine what the 24 hour motor config and calibration actually was? Secondaries or not? Fueling/Spark changes? Given how long ago this was, time could be running out on getting the first person accounts.
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1984 Corvette Z-51/4+3 SOLD
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1992 Corvette ZR-1 Black Rose/Cognac #458
2014 Honda VFR Interceptor DX
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Old 04-23-2014   #148
Hog
 
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Default Re: My last effort

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Originally Posted by Mitsumark View Post
.Yes..Car is burning about 1/2 qt in a couple hundred miles according to dipstick and smoke.
Is the car still using this much oil?

In regards to oil being contaminated by gasoline, is that with the LT5's very large oil capacity, this effect is muted somewhat moreso than say a standard 5 liter capacity in other vehicles.

To actually wash down cylinder rings with raw fuel the injectors would require a very very rich condition. One almost unattainable except for say an injector that is stuck open, or a cylinder that isnt firing.
Washing down the rings was far more of an issue in the days of the carbeurator.

I'm very pleased that this issues appears to be working itself out. Being stumped with an issue, if very frustrating. And to be honest, makes me apprehensive about ZR-1 ownership.
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Old 04-23-2014   #149
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Default Re: My last effort

So, I've read this thread from the beginning and I, too, am glad to see this is working it's way out.

I know that OP had mentioned only 2 plugs were wet with oil, but is it possible there is excessive blow by through the PCV system?

I had this issue with my big block Chevelle. It was all 8 plugs, so diagnosis was much easier, but I vented the valve cover to atmosphere and blocked off the back of the carb where the PCV system hooked up. No more oil consumption and the plugs remained dry.

Perhaps venting the crank to atmosphere and blocking off the PCV system would stop the oil consumption...or maybe an oil separator installed in the system would work.

Modified motors can make more crank case pressure than stock ones, especially with increased cubic inches. They can push oil through the PCV system and into the combustion chamber.

Just a thought.
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Last edited by cadillac531; 04-23-2014 at 05:56 PM.
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Old 04-24-2014   #150
Hib Halverson
 
Join Date: Jun 2005
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Default Re: My last effort

Quote:
Originally Posted by XfireZ51 View Post
Seriously tho Hib, with your journalistic prowess, why not determine what the 24 hour motor config and calibration actually was? Secondaries or not? Fueling/Spark changes? Given how long ago this was, time could be running out on getting the first person accounts.
I was there.

I wrote most of the magazine accounts of the Record Run...Road&Track, Vette Magazine, Corvette Enthusiast and what was on the old ZR-1 Net web. I wrote what's on the current Registry site. I moderated the panel discussion at the 20th Anniversary of the Record Run.

I knew the two guys who conceived the idea. Four of the drivers are personal friends of mine. I interviewed the team owner several times. I know one of the guys who worked on the engine at Stillwater

I'm confident that I don't need to determine much more about the RR and that the information I've posted to date is accurate.
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