hi! guys i bought a 1990 mustang 5.0 and it wont start the guy replace the fuel pump fuel pump relay and fuel filter which i replace the car has between 30-45 psi off fuel pressure coming out off the fuel pump it has plenty off spark it cranks over but it wont start the kid that i bought it from replace the computer but he bought it used so it problably doesnt work my question is i went to auto zone and theres 2 different part # im afraid im going to buy the wrong one knowing that the kid put any 5.0 computer on there so i wouldnt know which one it is how can i find out which one is the right one.

 

Just look at the description of the alternatives, you don't want a CA programmed ECM (if you don't need to), and the correct one based on the transmission type you have installed. Could you share the part numbers you are looking at?

 

if its manual trans you need and a9l if its auto a9s i think i forget the other letter for it, but if you have spark and fuel pressure i wouldnt think its your computer, have you checked your timing or have you messed with it, if not id try a new dist modual mine went three times with in 5 years on my car...thats what i got for buyin cheap now i have an msd and i havent had a prob in 3yrs, just sharing my experiances with a similar prob...

 

i havent check the timing but the car trys to start but it wont start the kid try that hea said i didnt work how do i check the timing

 

how would i kno if the timing is off can you help me i really want to get my mustang going.

 

whats a dist modual?

 

whats a dist modual? and ho do i know my timing is off.

 

The distributor(ignition) module is the small plastic piece that is mounted underneath the actual distibutor cap on the distributor shaft. But if its trying to start and not quite making it I would really recomend that you get the timimg checked out before you worry about the module.

 

The computer would control the injector pulse but I am doubtful it is the computer. Crank it a few times and pull a plug to see if you have fuel getting to the chamber, for the engine to run you need Air, Fuel, and Spark, would probably be good to check the firing order as well just to verify. The kid down at my Autozonehad his 1,5,1,4,2,6,3,7,8and could not figure why it ran like crap, correct order is 1,3,7,2,6,5,4,8

 

Check this How to Solve an EFI NO START procedure...... an LUK.