# Trouble getting past 4000rpm



## dburone (Apr 2, 2004)

The thing is that with both barrels open in my e16s turbo, the engine starts to fail at about 4000rpm, y tried to leave the second barrel closed, and the engine climbs all the way to 6500rpm without trouble.
A friend told me that the spark could be too weak so i searched the web a while and saw that i should close the spark gap a bit, now it is ar .25 . After that the car runs lot better, but not perfect yet, so i guess ill have to change the coil. Isnt there any other way to solve this?
Thanks


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## velardejose (Sep 9, 2004)

Have you tried a 0.20 gap?
Maybe its just lacking gas...
Do you have an a/f ratio meter?


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## velardejose (Sep 9, 2004)

Forgot to ask, what fuel pump do you have?
How are you regulating the fuel pressure vs boost? you need a higher than boost fuel pump pressure
You need one of those... 
http://www.holley.com/HiOctn/ProdLine/Products/FMS/FMSFP/512-504-5.html
It compensates the fuel pressure acording to the boost you have


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## velardejose (Sep 9, 2004)

What spark advance are you using?


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## dburone (Apr 2, 2004)

At first i had the stock .39 gap, now yesterday it was at .25 and it was a lot better. Today i made some mods on the air bleeds on the carb and that problem is finished
I guess trouble starts when fuel mixture is too rich.

I have an mpfi fuel pump that can give 50psi, with a home made fuel regulator that rises pressure when bost starts.


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## velardejose (Sep 9, 2004)

And timing?


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## dburone (Apr 2, 2004)

velardejose said:


> And timing?


Timing is stock


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## dburone (Apr 2, 2004)

Finally the problem is gone, and im putting in 8 psi now. The idea was to go 7 psi but i calculated wrong, is 8 psi too much on a 9.0:1 cr engine??


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## Crazy-Mart (Jul 14, 2002)

as long as it doesnt ping/detonate its ok ... make sure you use the highest octane rating that you can buy it will help alot.


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## dburone (Apr 2, 2004)

I am putting 97 octane gas. and i didnt see any pinging or sound of any kind.
The engine also acelerates all the way to 6500rpm very smoothly. 
I think everything is going ok


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