Cutting out at high rpm...

[dczsvt]

Im having a problem with my 95 Cobra. when I go get on it it cuts out/hesitates at 4500rpm. Some friends believe its fuel or ignition but then everything is new (bbk 255lph fuel pump, fuel filter, NGK iridium spark plugs, MSD plug wires, remaned distributor and MSD cap and rotor). Ive checked fuel pressure and it was fine, cleaned the mass air and throttle body and it still does it. Before I took it into the shop to get the coolant leak fixed it would go to "redline" with no cutting out or hesitation but the only thing that was replaced in the ignition at the time was the distributor (buzzing sound). When I found my coolant leak it ended up being a cracked head so I got 2 used heads but they were non emissions heads. Ford said they could install them and would remove my emissions but couldnt pass inspection afterwards. Anyone have any ideas? ive tried explaining EVERYTHING possible

 

[RockstarMentality]

does it always cut out at 4500, and ONLY at 4500?

 

[dczsvt]

anywhere between 4000-4800 from second gear on, sometimes in first if i mash on the gas itll cut out at 3500. would blocking the EGR help? since my emissions are practically gone

 

[Venom351R]

what kind of MAF is it?

 

[dczsvt]

 

[dczsvt]

Well I took it to Ford today to ask about if taking off the EGR valve would help, he said he wanted to test the fuel pressure under a load, so we did that and it stayed around 45-50psi the whole time, so then he thought maybe these heads call for a different spark plug (i wouldnt think that they would if they have the same casting number) anyways I checked and they can take the same plug. So then he unplugged this diode looking thing and told me to drive it, so I did and it doesnt cut out as much, he said doing that sets my timing to 10degrees instead of 12degrees. So he said to bring it in tomorrow and theyll check everything all over for free (since ive spent about $2500 there already)

 

[modo]

coil