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Ford Mustang Forums Tech Related Engine & Performance 5.0 Pushrod Guys

mass air problem

vinny8989 23.09.2014, 14:25
Have a problem. I have an 89 mustang 5.0 ran great with new top end. Stock block. Aluminum 75 mm throttle etc. Was running stock mass air and injectors and computer. Swapped to new mass air and 3olbs and it wont runn I also have new flashed computer for those. Still nothing. Please help.
BAD5.0 23.09.2014, 21:36
When you say it won't run, does it not start? Or rough idle then die? Im sure you are aware, but be sure everything is calibrated correctly as far as your electronics go, and did you use all correct compatible pushrods, rockers etc? Make sure timing didn't get bumped out of alignment, make sure you are getting fuel and spark.
po-po 5.0 24.09.2014, 14:09
Does it idle with the meter unplugged? If so your "flash" (you can't flash an '89, you need a chip) is wrong.
vinny8989 27.09.2014, 11:12
Yes everything ran perfect until tht new mass air and injectors. So I need a chip to run those? What kind? Timings is still set. It will fire for a second then die.
jdholley 29.09.2014, 13:51
Make sure all the vacuums lines are connected.
Aerocoupe 30.09.2014, 19:15
Never heard of a Fox EEC being flashed, only chipped but with your mods a stock EEC should be able to compensate with a correctly "calibrated" MAF. I ran a Pro-M 75mm with 24lb injectors for years with cam, heads, upper and lower intakes, higher compression, etc and never had a problem with a stock A9L. It ran a shit ton better with the SCT chip and a dyno tune but it ran on the stock EEC. What brand of MAF is it and are you 100% sure it was calibrated for 30lb injectors? Are you hearing the modified EEC prime the fuel pump and then shut off after you turn the key to run? Might be an issue with the new EEC so try your old one. Another thing would be to check for codes.

vinny8989 01.10.2014, 14:41
Its 75mm pro m. I hav two. Both calibrated for 3os. Also tryed both computers. Fuel pump primes and shuts off as advertised. Im going to take it all back apart. Had to miss something somewhere.thanks guys
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