High RPM Miss Continues! Valve Float??
09-01-2010, 12:01 AM
#21
Ok well I think I got it figured out...Fingers Crossed...
I ordered some Patriot Gold Extreme dual springs based on Wrd1972 and Loyd Elliot's advice...
Install height on the patriots are 1.800 just like my old ones are suppose to be..
I recently had the valve job redone by a local machine shop so I figured I would check install height before I put the new springs in to be safe..
First one was 1.850
I guess they never re shimmed the springs to 1.800.... So not only were the springs almost 9yrs old but they were too tall so even less seat pressure...
I think I may have FINALLY figured out my high rpm problem!!
Thanks for everyone that provided me info and helped me out!!
Matt
I ordered some Patriot Gold Extreme dual springs based on Wrd1972 and Loyd Elliot's advice...
Install height on the patriots are 1.800 just like my old ones are suppose to be..
I recently had the valve job redone by a local machine shop so I figured I would check install height before I put the new springs in to be safe..
First one was 1.850
I guess they never re shimmed the springs to 1.800.... So not only were the springs almost 9yrs old but they were too tall so even less seat pressure...
I think I may have FINALLY figured out my high rpm problem!!
Thanks for everyone that provided me info and helped me out!!
Matt
09-01-2010, 12:46 AM
#24
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I wish you luck, I am trying to track down the same issue but my springs have 150# on seat with 400# open so I don't think valve float is going to be my problem 
09-01-2010, 01:37 AM
#25
Fuel System
Injectors, fuel Pump, Regulator, filter and fuel lines
Ignition
Dynaspark, plugs, wires, coil, ICM, grounds and checked all the wires in the harness...
Now Valve train
Springs, push rods (length and if bent) Rocker adjustment and spring height...
If all of that doesn't fix it I will need some gasoline and a match...
Good Luck!!
09-01-2010, 05:24 AM
#26
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While you're replacing your valve springs, replace your lifters too. My old CC306/LE2 car ate valve springs and lifters every couple of years. First time I replaced the springs, the problem got better, but wasn't fully resolved. The lifters were collapsing under the new found pressure.
09-01-2010, 02:38 PM
#29
replace valve stem seals if they are old also
09-01-2010, 05:18 PM
#30
when you remove springs.....hold valve tip and hold valve up against seat and rotate with fingers.....it should be smooth....but if you did bend a valve you would feel it while spining.....when you did push RPM's with float you "may" have kissed the piston....hopefully not but check each valve.
replace valve stem seals if they are old also
replace valve stem seals if they are old also
I have all new Viton seals going in too...
Matt
09-02-2010, 07:47 PM
#31
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Edit: Save your well noted 306 hate. Many years ago when I got it, it was the only choice besides a custom solid roller. Unlike most of the people who run a 306, actually ran.
09-02-2010, 08:41 PM
#32
Daily driven and abused for 4 years with that combo, you'd be surprised what gets eaten through.
Edit: Save your well noted 306 hate. Many years ago when I got it, it was the only choice besides a custom solid roller. Unlike most of the people who run a 306, actually ran.
Edit: Save your well noted 306 hate. Many years ago when I got it, it was the only choice besides a custom solid roller. Unlike most of the people who run a 306, actually ran.
Don't know anything about the 306 hate...
09-05-2010, 12:53 PM
#33
OMG!!! This damn car is killing me...who wants to buy an 11.90 LT1 with a miss????
Changed out springs to Patriot Gold Extremes shimmed to 1.780 - 1.800 as instructed by Loyd Elliot
all the valves slid up and down and turned fine....
Push rod length is spot on! and the valves are all adjusted to 1/4 past preload also as instructed by Lloyd....
Car still runs like **** at 5800 and up!!!! Every time it would start missing the check engine light would come on and it didn't want to idle... Shut the car off and turn it back on and the light would be off and it would idle great?? I don't know what else could be the problem??
Harness??
PCM issue???
Cam Issue??
Anyone have any insight???
Changed out springs to Patriot Gold Extremes shimmed to 1.780 - 1.800 as instructed by Loyd Elliot
all the valves slid up and down and turned fine....
Push rod length is spot on! and the valves are all adjusted to 1/4 past preload also as instructed by Lloyd....
Car still runs like **** at 5800 and up!!!! Every time it would start missing the check engine light would come on and it didn't want to idle... Shut the car off and turn it back on and the light would be off and it would idle great?? I don't know what else could be the problem??
Harness??
PCM issue???
Cam Issue??
Anyone have any insight???
Last edited by MattSapp95_T/A; 09-05-2010 at 12:59 PM.
09-05-2010, 04:50 PM
#39
I assume its good....
he tried adding and taking away timing and nothing changed...Air fuel is good...
It did it with the old tune too....
I think I may try another harness and PCM when I hooked this one back up I accidentally put the ground by the knock sensor on the starter and melted the wire pretty far up...I traced it back until I found good wire and spliced in and re grounded it but I don't know if it effected anything else...
It drives and runs fine until 5800.....
he tried adding and taking away timing and nothing changed...Air fuel is good...
It did it with the old tune too....
I think I may try another harness and PCM when I hooked this one back up I accidentally put the ground by the knock sensor on the starter and melted the wire pretty far up...I traced it back until I found good wire and spliced in and re grounded it but I don't know if it effected anything else...
It drives and runs fine until 5800.....