Huge loss in power at 5k

[spook302]

This may be a problem that I overlooked but i have been running 13 psi for a littl while now. The other day I pulled my car into the shop and pulled all my piping off, cleaned it, new rubber and clamps. Put it back together and replaced some vacuum lines and removed allot. I took the car out after that and it pulls to 15psi easy now. So I had a leak, probably a couple that are now fixed. As soon as I hit 5 grand its like the bov or wastegate is just dumping. I am pretty sure its the bov. Its a stock 1g. I own a 91 gsx. Anyways its scary. It just dumps most of my boost at 5k, 15 psi. Car runs great but cant pull past 5000 like I used to with 2psi less. It boost quicker now that there are no leaks anymore. What stupid thing am I overlooking? Does my stock bov dump at 15?

 

[LTUDSM]

This may be a problem that I overlooked but i have been running 13 psi for a littl while now. The other day I pulled my car into the shop and pulled all my piping off, cleaned it, new rubber and clamps. Put it back together and replaced some vacuum lines and removed allot. I took the car out after that and it pulls to 15psi easy now. So I had a leak, probably a couple that are now fixed. As soon as I hit 5 grand its like the bov or wastegate is just dumping. I am pretty sure its the bov. Its a stock 1g. I own a 91 gsx. Anyways its scary. It just dumps most of my boost at 5k, 15 psi. Car runs great but cant pull past 5000 like I used to with 2psi less. It boost quicker now that there are no leaks anymore. What stupid thing am I overlooking? Does my stock bov dump at 15?

you sure ,that yo did the vac lines correctly? where is your bov vac line connected to?
The other thing,that i can think of is the MBC ,Are you sure after pulling the vac lines off,your MBC isn't connected backwards?

 

[DSMopar]

It sounds like fuel cut, check for boost leaks... what are your mods?

 

[spook302]

I have a header, mbc, gutted cat, Hard piping for the intercooler.

I got the car with a snapped tb belt. I never got to drive it or any dsm till I bought it off my buddy for cheap. I pulled the head off. Clean everything on the engine. Pulled another head from a donor motor, rebuilt it with new valve seals and micro polished everything. New water pump, belts filters, All seals, hoses fluids etc..... The car had hard piping on it when I got it. The exhust man was thrashed so I Found a header in the area for cheap. I Dont know some of the limits with tuning the car. I know with the stock fuel system I dont want to run more than 15 psi, My mbc is adjusted so I wont go higher than that. I removed all the vacuum lines and egr I didnt need. I adjusted my cable for wot and idle. The intake was cleaned out as well as the throttle body and pretty much everything else. I just want it to run good and the best it can before I get a chance to buy some more goodies for it. Just wondering how these cars react to higher boost, how much is too much. What can I tune to make it run the best before I get bigger injectors, exhuast, fmic,fpr. The car came with a palm pilot with the software and data link and everything. Some ahole decided to steal it from the car. He didnt even take the pen for it or th charger or anything. So that is next on my list to buy.

 

[killahb33]

bump

 

[concept4g63]

WTh this isnt a honda forum

 

[Thomas91169]

sounds like fuel cut to me as well. you still have a leak, and now being able to pressurize to 15psi means your turbo could very well still be pushing far more, and thats what your MAS sees (since its before the turbo) and tells the ecu "holy shit theres way too much ####ing air coming your way!" Even though most of it is getting lost due to leaks, the MAS does not know that.

without a real boost-leak tester made, simply removing and reinstalling piping does not tell you whether or not you repaired a boost leak.

also could be spark blowout on the plugs if they are fouled or gapped too wide.