EFI to CARB conversion help
#31
How would we know that the ‘86 had a carburetor unless you said it does? Several if not most engines in the car/truck lineup were fuel injected by then.
You can can fiddle with a carb and get them to run very good but it will still need periodic rebuilds and maintenance. How much time do you spend on your ‘96 working on get size, idle mixture and choke adjustments? Sequential fuel injection is much more precise than a carb could ever hope to be. I have carbureted vechicles but they are not my daily driver.
To Zbrown that brought this thread back from the dead,
What testing have you done? Did you just throw ignition parts at it? Are there any fault codes stored or active?
#34
#35
#36
I can certainly answer the question as to "why" somebody would want to swap their EFI to a carb. It's because our EFI computers are getting old, no matter where you look (junkyard, eBay, etc.). These old computers start exhibiting very strange behaviors due to cracked solder joints, dry/burst electrolytic capacitors and so on. To go even further, our sensors that support the EFI system are getting old, and the aftermarket replacements are hardly worth exploring, let alone putting on the engine. They are just really junky. So when your computer is going bad with no new replacements (other than spending enough money to buy yourself a new truck), along with worn out or cheaply built sensors that give faulty information, carbs start sounding like a real good alternative. EFI is great, but when the parts to maintain that system just aren't there or any good, the EFI is just as unreliable or worse than the carburetor...
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#37
#39
#40
#41
#42
There is no difference in the basic block/heads for a carb'ed versus EFI small block in this era truck.
Best guess is a vacuum leak perhaps.
It could be a contributor to your idle issue.The Speed Density EFI setup requires at least 114 LSA to work properly in most scenarios. Lumpy cams typically result in poor performance and stalling. Rare I have seen one cause a high idle.
#44
needs for the conversion
While you can use the two internal low pressure and external high pressure fuel pumps, I find they are more to fail and the fuel return setup can be problematic, it might be better to drop the tank(s) remove the pumps and replace them with fuel line to the in tank filter then replace the high pressure pump with a new Carburetor low pressure 'Fuel Pump', but be sure to wire the fuel pump through the inertia power relay in case of accident.
Personally I use C6 or Manual Transmissions and I remove the computer and disassemble the wiring harness to make it cleaner and less of a headache to use, as well the open ports are perfect for running wiring for extra lights, or any 'gear' I need wired.
Take your time, use your phones camera and label everything!
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#45
I have a '95 F 150, 351 Windsor, E40D trans, speed sensor located on top of rear axle. First the speedometer went haywire, jumping all over the place. Then the engine started stumbling while driving and trans would upshift or downshift depending on which way the wind was blowing. Truck would stall when I put it in reverse. Everything I read pointed to speed sensor so I replaced that. Driving down the road 10 minutes later and it all starts happening again. More reading tells me that something in the speedometer cluster is sending a screwed up signal to the trans. Found another cluster in a salvage yard and changed that. Now the truck runs bad just like before and neither the speedometer or tach work. My plan is to go with a an Edelbrock 1406 because I have one, Edelbrock 2181 manifold that I paid $125 for in the original box that looks like new, fuel line regulator using the existing tank pumps, and replacing the E40D with a C6. Do all C6's have mechanical speedometers and what do I use for kick down linkage? I figure I'm going to have to put mechanical gauges in there anyway so I might be able to replace the entire speedometer cluster with one I build to fit the hole in the dash. I have a new factory stock distributor. Can I use that and the stock CD box or do I need something else? I know there are a lot of questions here but I only want to do this one time..
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