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gtp vacuum problems help

GTPSHAWTY

GTPSHAWTY

New member
lets seee.. i have a problem i keep getting a his of air... which would make car idle low as hell then it would recover.... now i just realized it blows the vac line off map sensor everytime... what could cause the i guess you can call it backfire in the vac system?

when the loud puff or hiss happens the car would suddly die then hard start. it usually starts on the dime or start at low idle then rises to normal after a second or two. the hoses are new and all the t's are new... it fit perfectly with no slack... it would either blow off the t or off the map sensor.. but only in that area... the hose is ran in this order... bbv>t to fpr>t to lim>t to map and boost guage

some background..... car had chipped piston.. got a new block swapped over cam and top end.. ... would being a tooth off in timing or something cause this

it only does the puff on low slow accel.. like pulling outta a parking spot or something

my boost guage at idle is around 0 to -5 when slow accel it goes to -10 to -15 then starts positive as i put more into it... but i thought it should be -20 or area at idle


mods: xp cam rollmaster single roller 3.4 pulley ported lim and blower......ngktr6 plugs comp cam pushrods.. 42's injectors lq4 maf slp headers..
 


try tighter vac line. if its the stock hard line with old rubber @ the end, change that. mine was coming off to. new vac line to it sealed it good.
 
yeah should be 19-20ish, and as scottydoggs said replace those rubber ends...or as I did ALL the small vacuum lines
 
i just tried blocking off the bbv. didnt stop the puff... but i noticed.. when the puff happens the boost shoots up to 5lbs then car dies.. in maybe a second.. or less......... also with the hose on the vac is still 0 to -5 im soo dam lost it makes no sense.. never had this issue before
hell or anything like it
 


Update took blower belt off... to see if that help clear it up..... and it did the total opposite... it bogged like hell and the brakes even stiffened up.. but the loud puff was gone but idle wasn't greater than 5-600
 
Istarted car... walked to the engine and seen it... first time ive seen it before I just heard it... I'm changing them hopefully today.. weather has been ruff
 


fixed orings... and ziptied vacs... idle vac is still the same...... car still stalls. imma change my maf since i have a spare laying around.. just for ****s and giggles..... also think my flexplate is comming lose.. hear a lil tapp.. but no metal on oil stick.. so imma crawl up under there and check it out.. if the rain ever stops
 
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