1990 EFI to Carb Tachometer Hookup
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3rd Gear
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1990 EFI to Carb Tachometer Hookup
I have been searching the forums and have been unable to get an answer to my question. My 5.0 EFI sucked on my Bronco and never could get it to run good, so I decided to swap to a carb. I use the truck for hunting and farm work so this seemed the easier solution. When swapping the intake, I discovered that I had a roller motor which I didn't think was available in 1990, I guess someone changed it. I installed a Edlebrock manifold and carb, I also went with a GM style HEI distributor. Everything seems to work great, except I can't get the tach working, I thought we hooked up the correct wire. Can someone help me figure out what wire is the correct one to hook to the tach or maybe some other problem to look for. I forgot to mention that the truck was converted at some time to a SM465 manual transmission. The truck drives great with no problems, just want to get my factory tachometer working.
Hotshot
Joined: Jul 2020
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From: Near Salt Lake City
The green wire to the E core coil was the tach on your old EFI setup
Your original E core coil had a red on one side (possibly red with white) and a green on the other side
The red was the power feed from the ignition switch
The green went to the distributor with a pigtail take off going to the tach if equipped (that green might have a yellow stripe or hash)
For 1990, I have a EVTM and can post the schematic if you need
Your original E core coil had a red on one side (possibly red with white) and a green on the other side
The red was the power feed from the ignition switch
The green went to the distributor with a pigtail take off going to the tach if equipped (that green might have a yellow stripe or hash)
For 1990, I have a EVTM and can post the schematic if you need
Hotshot
Joined: Jun 2015
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It is pretty easy to diagnose and repair the EFI system but you must test the parts before replacing them and use Ford Motorcraft sensors. There have a few threads where the reman PCM/ECM has failed but new computers are also available if you want to go that route. Aftermarket parts are so hit and miss that the new part might be worse than the part you replaced. Converting to carb is definitely something I would not sdo but as long as you’re happy with it.
Anyway, your truck has a roller block with a flat tappet camshaft. My ‘89 F-150 also had the threads tapped for the spider.
Anyway, your truck has a roller block with a flat tappet camshaft. My ‘89 F-150 also had the threads tapped for the spider.
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