5.0 HO Conversion problem

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Oct 11, 2005 | 12:29 AM

bronco4x450ho

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5.0 HO Conversion problem

ok i just finished converting my 89 bronco from non-ho to HO. It runs good, idles fine, but will not make any power past 3k-3500 rpms. It just flat lines and hesitates. I tried swapping injector wires 5 for 3, and 4 for 7. But that made the idle unusually high and sounded rough so I wired it back. My bronco originally had 19lb injectors on the non-ho motor and ran fine before the swap. Im really stumped on this one. Ive heard of many people doing this swap and didn't swap in another computer and ran fine. Only thing i can think of is maybe the TFI module is bad, but it was fine last time i used it which was like around jan.

Oct 11, 2005 | 06:19 AM

IB Tim

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Dec 20, 2005 | 08:21 PM

terryr

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If you're trading wires, you need to rewire 4 of them from nonHO to HO. Can't remember which 4 off the top of my head. I would suggest an HO computer.

Dec 20, 2005 | 10:25 PM

rich636

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I've spent 5 hrs trying to figure out why my stang ran like crap after reassembly once...I had it set up for the non-HO firing order...definitely rule that out.

Dec 21, 2005 | 09:41 AM

Kemicalburns

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From: Bend,OR

your running speed density on your bronco. its Batch fired so moving injectors shouldnt make a difference. Unless you have swapped to mass air? changing the plug wire firing order is all thats necessary. you kept the 19lb injectors on there correct? and are you still running your 89 ecu?

Dec 22, 2005 | 05:37 PM

bob1987f

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if you changed over to mass air it might be a bad mass air sensor. i had this just happen on my nissan pickup...would idle fine, but stutter at 2500 or higher

Jan 7, 2006 | 09:47 PM

Chevy_impala57

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how did u make ur truck ho?
Put whole mustang motor in? and efi
Put mustang motor in with out mustang efi and left truck efi
or jsut put mustang efi in

If u put a whole mustang motor in with the truck speed density, It may not be compiseating for the change in cam.

more info to be help