I have a 99 Ranger with 89 HO in it ! The guy I bought it off of had a 88 ECM and I'm wanting to know if it will work on it ??

 

As long as you have the correct wiring harness for that computer to be hooked to a 302. 88 HO engines are the same engine as a 89. No diffrence. However.....88 HO engines didnt have MAFS unless it was a California car and in 89 all of the HO's had MAFS. Just make sure you have the right wiring harness for that 88 ECM and you should be all good and if your 89 came with a MAFS and the 88 ECM is not a Cali ECM then just dont use the MAFS. Hope all this helps.

 

As said above, only the cali 5.0s had mass air in 88. The rest of the 88 cars had speed density. The 89 an up cars are speed density. Just do yourself a favor and buy an A9L. If I wasn't doing the megasquirt III on the cobra instead of the fox I would sell you my A9L.

 

+1 on the A9L, I went through this years ago on my 5.0, I had to get the right harness to swap it to MAF.