All out of tricks, breaking up 5300

[Alaskabuick]

Man this is getting old my Brothers.

My car had the wrong valve springs and was floating the valves last fall. Over the winter I had the Behive springs installed on the GN1s. The car has a 212/212 roller. I do not know if the car has the 885 or 853 roller lifters (hope I got that right Race or street), all the reasearch I did points to the 853's or what ever is standard in a ductle roller cam kit from comp.

It will break up under boost or no boost at the same approx rpm.

Coil pack new and good
new Module
Have tried plug gap .35 down to .28
New taylor plug wires
crank sensor is not rubbing
AF on Fast is where it should be when I log.
Volts are good (have a volt booster, can they cause problems?)

Have ran the valves a million times, any where from 1/16th turn past zero lash 3000ths, 1/4 turn, 3/8th turn, and 3/4 turn 30,000ths.
By the way my valves terrain in very quiet even at 1/16th turn, suprising.

When the car breaks up I can hear valve terrain noise, it wants to pull up 6k without a doubt.

If I short shift the car it pulls strong as hell. When the car is left in drive to shift itself it almost seems confused when it hits this breaking up point.

I am at the end of my bag of tricks,

any ideas Guys?

Dennis

 

[441120]

Is there any rev limiter in your engine control?

 

[Turbo6inKY]

Is there any rev limiter in your engine control?

2nd on this. If it's breaking up at the same spot every single time, and you've done all this ignition and valvetrain work, I'd move upstream to the computer.

 

[Alaskabuick]

rev limit

Running fast system. Have set the rev limiter at 6800 and no change?

Maybe I will try setting is low like 4000 and see if the symptom is the same at that rpm? Or if it corrisponds to the tac.

Thanks for the input.

Dennis

 

[ChrisCairns]

Are you sure you're hearing valve train noise and not detonation?

 

[Alaskabuick]

detonation

I have considered this but ruled it out. The car has the same syptoms with no boost just running it up to 5000 rpm or so... will even do it in Neutral.

running 100 octane, 20 pounds of boost and 18 degrees advance.

I had a buddy of mine has been running race cars for years ride in the car today, said he would almost guarentee that it is not valve float.

He says the it runs too good after the breaking up happens, once I shift and drop the rpms the car comes right back witout issue. This is just his opinion and is not that familar with Turbo 6 cars, but is a well experienced guy.

Hell maybe ill try something simple like a different plug? My buddy seems to think it is electronic?

Thanks,

Den

Are you sure you're hearing valve train noise and not detonation?

 

[onefastcar]

Try retarding the timing and see what happens had same issue and runs the best it has, yours is a lot different animal but its worth a shot, had valvetrain noise at same point in engine rpm and now its gone.

 

[ijames]

Couple of random thoughts: you don't have a DIS4, do you? Also, check the cam sensor setting and then try moving it a few degrees each way (about 1/8" at the cap edge).

 

[Alaskabuick]

I just set the cam sensor, you saying move 1/8th anyway?

Not sure what a DIS4 is?

Thanks

Dennis

Couple of random thoughts: you don't have a DIS4, do you? Also, check the cam sensor setting and then try moving it a few degrees each way (about 1/8" at the cap edge).

 

[FHW]

18 degrees ????
I use 26 also try closing your gap to .022

 

[psiedv6]

Just A Silly Thought But Do You Know If Fuel Pump, Filter, Or Fuel Line Is Good.
Had Similar Problem Years Ago.

 

[ijames]

Yes, try moving it an 1/8" from the "correct" position. One way it may not start, and the other way may clear it up . A DIS4 is a CD ignition box by MSD that connects between ignition module and coilpack, that is known to have issues with FAST systems over about 6000 rpm (the latest MSD release is supposed to take care of this but the old ones had issues).

 

[Alaskabuick]

cam sensor

Ok it is worth a shot, Ill give it a try.

thanks..

Yes, try moving it an 1/8" from the "correct" position. One way it may not start, and the other way may clear it up . A DIS4 is a CD ignition box by MSD that connects between ignition module and coilpack, that is known to have issues with FAST systems over about 6000 rpm (the latest MSD release is supposed to take care of this but the old ones had issues).

 

[Alaskabuick]

cam sensor

Tried moving the Cam sensor as recomended, no change.

New coil pac and all the goodies.. no change.

Next!!!!!

 

[turbo2nr]

Swapped the Alt. recently?
Charging problem?
I had the wrong alternator in the right box from the parts store. Car ran just like you described. Diodes were wrong in alt. Car ran strong untill mid--high RPMs. Then it broke-up.. Could not figure it out untill I went back to the last thing I touched.

 

[ijames]

Sorry, I'm out of ideas outside of the ecm for something that would cause a breakup at a fixed rpm, irregardless of how fast or slowly the engine is accelerating or what the load or boost is, except for valvespring/cam/lifter/rocker and you say you are confident those are okay. I know the beehive springs should be able to handle your lift, but maybe you have retainers hitting valve seals or the guides? Or ...

 

[SPOT MY 6]

Once the car is started, disconnect the cam sensor and see if the problem goes away. Post results.

 

[Alaskabuick]

Altenator is one thing I have not tried? Maybe Ill try swapping out off my turbo t? Maybe the volt booster is giving me hell? When I log a run on the fast it shows 14 + volts.

Spot my 6, do you mean to just unhook the cam sensor and run the car car up to rpm?

When the car hits the break up point, as soon as I shift and drop the Rpm's, it is like it hits a live wire, right back on it without hesitation. Has never really missed or backfired.

To tell you the truth guys the car is insanly fast as is, cant imadgine if it would run right.

Den

 

[SPOT MY 6]

Spot my 6, do you mean to just unhook the cam sensor and run the car car up to rpm?


Den

That depends if it happens when the car is not under load. If you have the car in neutral, does it break up at that rpm? If so, start the car, disconnect the cam sensor plug, and bring it up to that rpm in neutral. See if it goes away.

If it only happens when the car is under load (driving), start the car, disconnect the cam sensor plug, then go for a ride and see what happens. Its a test that will cost you $0 and is quick. My stupid cam sensor has made me scratch my head plenty of times. Just a suggestion based on my personal experiences...

Let us know what happens (if anything).

 

[Alaskabuick]

no diff

Tried unhooking the cam sensor, no change.

Yes the car does do the same thing in Nuetral as well.

Maybe my 212/212 is done at that rpm, seems more like 5500 then 5300 it breaks up at now?


Dennis