johndeeregreen

I have an 87 fox with a 5.0 that has all DSS internals ect. since putting all new gaskets in the motor new plugs cap and rotor.... it has begun this backfire through the air box its a loud popping noise very hollow sounding i have tried to adjust the idle and set the timing ect. "remove the spout connector set at -10degrees and then reinstall spout" still same problem. I haven't been able to diagnose the problem anyone out there have any helpfull suggestions please i really want my car back and i had no problems before with it.
Im running 24lbs injectors 24 lbs maf pro mass bbk regulator 255 pump pressure at 30 lbs give or take throttle
car will run wide open but hesitates and backfires at idle and will not hold a steady pace down the road jumps all over the place and revs up and spudders under holding a speed but once wide open runs good???? im lost help me please thanks in advance

JD1969

Sounds to me like you either have the firing order off or the distributor in wrong.

jbird1987

iv always been told u need 40 lbs of fuel pressure so thats what i alway set mine at. try bumping the pressure up around 38 to 40 and see if it helps. sounds like your not gettin enough fuel.

AdderMk2

according to your post, you have the timing set retarded.... please double check that this is a mispost, and not a grave error on your part with the timing light

johndeeregreen

I have the timing set and 10 degrees before top dead center and the firing order is 1-3-7-2-6-5-4-8 and i am running an e303 cam so ho firing order is what i would need also the block is a yy cast mex block not that it would make a difference at all the cam determines the firing order let me know what ya'll think thanks and i will jack the fuel pressure up and see what that does. thanks all for the input

AdderMk2

fuel pressure should be 39psi with the vac line off

johndeeregreen

thanks again for all your help and fuel pressure was the answer to this whole jammed up messed i bumped the pressure and problem solved car runs good now all i have to figure out is why my mechanical gauge keeps reading 220 degrees i know that can't be right for a ford chev maybe but a ford at 200+ ???? something isn't right there

berniemac73

thermostat, fan, or radiator.

johndeeregreen

t-stat new 190 fan dual electric new also and radiator just flushed and pressure tested????? still at a loss? can't finger it out

AdderMk2

while 220 is a little bit high, its actually quite normal.

the fans in an SN95 dont even turn on until then