you're MAF has to match your injectors. stock meter is rated for 19#ers unless it was a cobra then it would be calibrated for 24's stock. your after market meter will match whatever injectors you ordered it to, i assume 24's since thats what you had. if you upgraded to 30#ers(which is too big for your application, so is your intake.) put back on your aftermarket MAF and 24#'s which they should match im hoping. check your plugs and fuel PSI as stated above. check gap. and if plugs are fouled with fuel try adjusting the FPR(39 to 42psi vacoff)and injectors and MAF back to how you had them before. replace plugs with new ones and gap them correctly. should fix your issues hopefully.

 

Stock MAFs aren't caliberated, the ECU is....aftermarket MAF's are caliberated to the injector size, tricking the ECU to run them as if they were stock. You can run larger injectors with a stock MAF, but you will need a tune.

I run a Pro M 75mm MAF caliberated for 24's and I like it.

 

thanks for the input guys..i understand that my intake may be too big for my car.....i might try switching to a smaller intake soon but for right now ima try to get a mass air flow meter to match the 30 lb injectors...but the main reason my car is missing is because what you all mention..and that my fuel pressure and plug gaps are off...i believe so too...im going send my car to a tune shop..that specializes in mustangs...cause im fed up with this problem.

 

its not a stock block..its bored 30 over..

 

so you bought an after market block and had it bored 30 over or you use your "stock" block and had it bored over. in the case of the "stock" block being bored 30 over that wouldnt make a difference except for maybe ~2HP

in anycase if your injectors and MAF calibration are not matching you will haveA/F issues. i too agree with taking it to a shop to get tuned properly. you can probly yourself do the FP and plugs then take it down.

i meant more of a "matching" type of thing. i know its the ECU is calibrated to the injectors in the stock application. sorry about the way i displayed my verbage

 

it was an aftermarket block already bored 30 over and...one thing i forgot to mention the 24lb injectors i had in the car came with the cobra conversion kit i bought a couple of years ago...with the computer and mass air meter, but i replaced the 70mm with the 75mm and the car ran alot better...i believe the 75mm one is done now..it was used when i got it...it seems to give more and more problems recently thats y i rather get a new mass air meter to go with the 30's.....I believe also the plug gap is causing the missing under heavy accerleration.yea i can do those plug spacing myself....thanks for the advice...i know a shop that can get my Air/fuel mixture right...

 

75 or 80 should be good..but they have to be calibrated to run with the injectors u have...same problem i gotta get a mAF sensor to match my 30lb injectors.