Sputter around 15lb

[js402]

Car is running on e85, 80s, 6766 turbo tr6 ignition unsure of the cam I just know it's a big one motor pulling 10hg . Builds boost under 10lbs fine,. But once it's gets above that I get sputtering. Tried running with the cam sensor unplugged and it still does it. Wiped lobes???

 

[750H.P.V6]

I'd start with checking the fuel pressure and see if it goes up with boost. It should increase psi per pound of boost above the static fuel pressure. If that's good you might want to put in a fresh set of plugs and tighten up the gap a bit. Beyond those couple of things you'll have to post more info.

Neal

 

[TurboBuRick]

Too add to Neal's suggestions...

Check the crank sensor. Make sure the balancer is tight. It can come loose and walk out if not torqued correctly. Make sure the crank sensor is not rubbing the wheel. Check it on all three bladed of the wheel.

Check ecm plugs and chip for white corrosion as well.

Does it have a flat tappet cam? A worn cam lobe will be very rhythmic and consistent.

 

[dynoman]

What plugs are you running ??
Non resistor plugs have given problems with the stock ECM starting at about 13 - 15 psi , myself included .

 

[michael evans]

Can you post a log ?

 

[js402]

I don't run a power logger. Plugs are autolite 135(non resistor) gapped at.25. fuel pressure is good and I get 1 to 1 rise with boost. Cam is a dls roller. Ecm is still stock Chip is new and ecm plugs and grounds are solid.

 

[js402]

Dynoman what plugs would you recommend ???

 

[js402]

Here's the jist of the engine build. Previous owner took the motor 9.7 on gas with a different turbo and injectors...

 

[ScottHeidinger]

I’ve read a lot about failures with morel lifters. I don’t know if your issue is related but if they were in my engine I would think about swapping them out for Johnson lifters.


Sent from my iPhone using Tapatalk

 

[js402]

Ok. If they end up being my issue they'll get swapped out. But if it's not broke I won't fix it....

 

[dynoman]

Dynoman what plugs would you recommend ???

NGK BR6FS aka NGK 4323
non projected top resistor plug , you can get them at Auto Zone

 

[michael evans]

I don't run a power logger. Plugs are autolite 135(non resistor) gapped at.25. fuel pressure is good and I get 1 to 1 rise with boost. Cam is a dls roller. Ecm is still stock Chip is new and ecm plugs and grounds are solid.

What do you have for injectors ?

A/F ratio is important especially in this case. Need to find out if it is going lean (propally) or rich.

 

[michael evans]

I have tried a few different plugs and have found AC42TS are the best performing in our engines.

That is an AC Delco plug.

 

[js402]

I'm running 80lb injectors with a 450lph pump. BLM at wot is around 128

 

[michael evans]

The chip,turbo, and injectors must be made for each other.

The chip is the easiest (and cheapest) thing to change.

Call Eric at Turbo tweek and have him make you the prober chip.

 

[js402]

Chip turbo and injectors are all new and burned for the combo

 

[michael evans]

Good.

Need to either install or some how borrow an A/F ratio gauge set up.

 

[js402]

I think my fuel is good. I'm getting 1 to 1 rise and at wot my BLM is 128 but a standalone ecm is on my list for over winter projects.

 

[Pronto]

Have you tested the coil and wires?

 

[js402]

Ignition is a brand new tr6 just installed Thursday.