Car Miss And Bucks Under Boost

[l3igl3ang]

Hey guys I having a heck of a time with my dsm I kind of got out of them for a few years cars been setting since 2011 so I changed oil and got it running again and put new gas in it It was tuned on E85 so I used it first and it ran like crap barley got it home so today I stuck the old injectors back in and reset the ecu and used 91 octain gas in it and it runs good till u hit the boost then it misses and bogs down and bucks which is the same problem it had bad in 2011 which is reason I parked it. So I changed plugs which didn't help I believe we tested plug wires then as well. I did a boost leak test back then with luck on fixing it. Right now im just trying to get it to run like a stock turbo car at least anyway. The weird thing was the car dynoed at 410hp and was running great then one day boom it started doing this crap took it to a performance shop and the guy couldn't figure it out on what causing it and here in ft smith Arkansas there's no shops that dose DSM work so im stumped to what it could be.

 

[spyderdrifter]

Almost sounds like you're not pushing enough fuel to maintain the boost output.

 

[l3igl3ang]

O so I should do a fuel pressure test. u guys have any idea what PSI I should have on the fuel pleasure.

I will try to get a video of what its doing here in the next few days an post it so u guys can see it.

 

[spyderdrifter]

Fuel pressure should be between 40-45 psi.

 

[Dsmkauai]

Base Fuel Pressures:
For 2g's= 43psi
For 1g's= 37psi
Also what plugs are you using and what gap?

 

[l3igl3ang]

there NGKs im not sure what gap a buddie gapped them awhile back to what they was supposed to be for me.

 

[codym]

You said you did a boost leak test back then.. have you done a boost leak test since it suddenly started running bad?

Also plugs are BPR6ES Gapped @ .028" for a stock/near stock car.

Might try going a step colder with BPR7ES.

 

[l3igl3ang]

I think I my had found the perpertrader! I noticed today when I started it it was winning real bad from the back seat I figuerd it was the speakers from a bad ground loop it had been whinny for a long time and alsway thought it was the radio but there's no radio in the car now so i got listening and iy was coming from the fuel pump so I pulled it out and its rusty as heck so im going to replace the pump. And hope to god that fixs it. I was wondering would a stock pump work or should I get a walbro 255