1988 5.0

when the car is cold it takes a hile to start and when it dose start it will backfire when the car is warm it will start fine but id if u take the car past 3500 rpm it will fall on its face it has been convt to mass air i have put ford racing 9 mm wire on it msd cap and rotor new plugs timing is at 12 derges i run 89 in it all the time any help would be great

cobra1923

This is one that is going to take some searching.

When you set the timing, you did take out the little "pill" module hanging on the distributor? The timing needs to be set without the computer automatically adjusting it, removing the module makes it static

Are you getting fuel pressure when it's cold?

Could be the "MAF conversion" MAF sensor, O2 sensor, TPS or IAC?
Vacuum leaks could be causing some issue but it would usually start and then run rough if that were it

First visually look around and make sure there are no sensors unplugged

Then turn the ignition to "on" but don't start the car, hit the schrader valve on the fuel rail (put a rag or something down in front of it) gas should shoot out with about 40# of pressure so be careful. If it dribbles or nothing, then you have a fuel filter, fuel pump or fuel pickup problem

Those 5.0 injectors seem to foul up pretty easy, shouldn't cause major problems like what yuou have but I used to get mine professionally cleaned out once a year (until I just upgraded to some 30# when I got the SC)

then I would plug a code reader in and see if your computer has any codes and go from there

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2003 10th Anniversary Cobra Convertible
All Stock and staying that way... well maybe some pipes since it's so quiet..ahhhh! it's a sickness

1995 mustang GT vert - all black (almost back together)

1988 5.0

when i set my timing i did pull out the plug by the distributor i will have to check the fuel pressure i did see 1 vacuum line that looks pretty rough all the sensors r plugged in i was goin to go buy a new fuel filter today i know when i unplugged the the mass air meter it has thottle response so i dont know if it is the mass air flow cause if it is i am goin to put a new mass air flow and probley 24lbs injectors in it thank i will put a new post when i find out some more

1988 5.0

i put new plugs in it and a new fuel filter it is a little better but i still falls on her face at baout 3500 rpm

cobra1923

something def not right, check and make sure your intake track is tight (especially from the MAF to the intake). The dying out after 3500 could be fuel issue, do you have an adj regulator, might try tweaking it a bit to see if has any effect

__________________

2003 10th Anniversary Cobra Convertible
All Stock and staying that way... well maybe some pipes since it's so quiet..ahhhh! it's a sickness

1995 mustang GT vert - all black (almost back together)

1988 5.0

i dont have an adjustable one but the 1 that is on there just got replaced when i took the 4 banger out and put a 50 in