99CAMMEDSS

iTrader: (3)

Well long story short i put a Aem Tru boost controller on the car to bump the boost from 6 pounds to around 8-9 pounds of boost, it runs great on 6 pounds it doesn't cut out going into boost its real smooth, anyways i took it to get re tuned and dyno'd on 8-9 pounds well anything over 6 pounds of boost it starts to cut out real bad, im stumped i put new tr6 plugs and gapped them to .030, put some different plug wires, checked all the grounds and couldn't find anything, any help or opinions would be great thanks for any help!!!!!!!! All the specs to the car are in sig....

HUNTER02SS

iTrader: (24)

Cutting out as in like a mis-fire? If you have to much fuel it will mis-fire as well. What is your Fuel pressure under boost. You have enough fuel pump for the extra HP? Running lean will mis-fire and pop as well.

99CAMMEDSS

iTrader: (3)

Yes you could call it a mis-fire, I have a racetronix fuel pump with the hot wire kit, on the dyno the fuel pressure was dropping about 8-10 pounds he said thats a big drop but should be able to get it to run fine on 8-9 pounds not sure if he was right or not.

1BAD_LS1

iTrader: (36)

its fuel or spark.....

have your tuner check spark dwell settings.... gap your plugs a little smaller... check connectors for coil power...

check fuel pressure during the runs... make sure your injectors are large enough (check duty cycle)
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also what valvesprings are you running???? could it be valvefloat???

HUNTER02SS

iTrader: (24)

Your fuel pressure shouldn't drop under boost. Dropping 10psi. is alot.
It should stay the same, or go up per lb. of boost with a Boost regulated fuel pressure regulator. Do you have a Fuel pressure regulator? Which fuel pump you running?

99CAMMEDSS

iTrader: (3)

He tried for hours to get it to run right, and finally said that there is something wrong he said that the spark kept cutting out at the higher boost level, ive checked all connections to coils and they seemed fine, fuel pressure was dropping around 8-10 pounds wot, and i have 60 lbs injectors, Its got Partiot "Gold" .650" Lift Dual valve Springs.

TX RED

iTrader: (19)

I would say drop a second pump and buy a fuel regulator

Area 51

sounds too rich. whats the wideband saying?

MUSTANGBRKR02

iTrader: (91)

If he is dropping 8-10 lbs. of fuel pressure i would say too lean.

99CAMMEDSS

iTrader: (3)

Well for some reason it looks like the wideband shows very rich 10.0 and it maxes out on the rich side of the guage, going up the street my friend said he saw flames coming out of the exhaust when it started to misfire, then i drove back by were it started to misfire and there were black exhaust marks on the asphalt from the exhaust dump, so i guess that would mean very rich right?

Area 51

Yeah, I'm with you man but if it's really rich, like 8:1, then a 10 psi cut isn't going to do enough.

IT_SS

iTrader: (5)

lol, sounds like a supra

Area 51

Yep. 10:1 is probably the bottom limit of the sensor so I bet it's richer than that. lean it out some and you'll see the money.

black98ws6ta

iTrader: (77)

Sounds like the opposite to me. The tuner could have too much fuel commanded, that it is blowing out the spark, and dropping fuel pressure.

charcold-bowtie

iTrader: (10)

Assuming a f-body tune is like a truck.... I would say it could be burst knock in the tune. Sounds very familiar with what my truck did the first time I went from 6lbs up to 9. Just zero out the table in the tune. My FP would drop several psi, like 8, during a WOT run. No its not really ideal, and is now fixed, but it doesnt mean its going to go lean. I was OLSD as well.

black98ws6ta

iTrader: (77)

If the car was fine at 6 psi, and you went to retune for higher boost and the air fuel reads 10.0-1, you need to take some fuel out of it! That is definitely part of, if not all of the problem.

redfirebird

personally i think you are grtting a false rich reading with that being said you have a problem you shouldn't lose fuel pressure when your adding boost the car is going LEAN !!!!!

HUNTER02SS

iTrader: (24)

I agree. Losing fuel pressure under boost is not a good thing.

black98ws6ta

iTrader: (77)

Any car with a stock style fuel system is going to lose some fuel pressure, but keeping it at a minimum is good. Another fuel pump in the tank triggered to come on under boost would help.

at 10.0-1 on the dyno the car should spit some black smoke, were you able to tell anything there?

HUNTER02SS

iTrader: (24)

If you are losing fuel pressure, your fuel pump is not keeping up. Compensating for this in the ECU is a bandaid fix to a problem that needs to be fixed. Reading rich can be a result of the misfire, but if the cylinder is completely dead, it can read a lean condition if to much unburnt fuel is passed thru.