Long story short, my son's Bronco now needs to pass safety and emissions inspections, and I have my doubts about it passing with the stock non-computer carb system, my truck with the computer carb system spectacularly failed emissions before putting historic tags on it. Would it be worth it to put on an '87-'89 300 OEM EFI system on it, or sell it and look for, say a later Bullnose with a 302 EFI/AOD?

 

I thought about doing a EFI conversion as well. From what I read it's quite a undertaking. You have to change a metric ***** ton of stuff. I guess it all depends how much you like the truck, it's condition, how much you can get the parts for and if changing everything is worth the labor. I don't have to worry about emissions in RI, so I'm eventually going to ditch the feedback system, go duraspark, change the intake manifold and throw a bigger carb in.

 

If the engine is in good shape, there should be no reason whyit would not pass. They are not allowed to make a older engine do something that is never was designed to do. They do not expect a older engine to be as clean as a newer one, so if it's running good and in good tune, it should go through with the older carb system.

That means if it had a smog pump, it needs to be on there and working. It needs a cat convertor, make sure it's not been gutted out by a previous owner. You can buy new universal cats from the store, they used to be about $60. It probably had a EGR, it needs to be working.

 

I did put EFI on my 84 F250 in the late 90's. Was a learning curve as there was no forums for information like now days!

The manifolds will fit the older engine but a few bolt holes are not present for the EFI intake in he head, I swapped heads from the parts truck(fresh rebuilt, but took a hard hit and busted the block,bummer I would of swapped entire engine)

I pulled out the EFI harness and made it a self contained harness. I laid along side the 84's harness and used just 3 hook ups, battery,ground and switched power(run).

The fuel system was pulled including the tanks and installed. Then I found a BIG issue. My fuel gauge was reading BACKWARDS! In 87 Ford redesigned the fuel sending unit to be reversed of the older trucks. What a PITA that became as I had to have the newer tanks for the fuel pumps, I wound up switching the sending units and that corrected that issue.

I also swapped the serpentine belt system over.

I did all that to get better running engine over the EECIV carburetor. I got a better running engine but lost a few MPG AND could not lug the engine under 1200 RPMs while idling in the trails off roading.

Now I have a Oppy DP intake and carb and going back to DSII ignition.

 

I have heard other people say you can't beat the EECIV carb system on the 300 six for fuel mileage, even beats the efi system as you found out. But who can find a EECIV carb system that works by now, and who can keep it running when something breaks?

 

I agree. Just seems like it would be much more cost and labor effective to maintain or service what is there. Just my opinion but, for me, it would be much easier and cheaper to replace an EGR valve and or a catalytic converter, plugs, PCV, than to start an induction conversion. As said, emission requirements are based on vehicle specifications.

 

There are lots of things to go wrong with that system, just like any other complex computer controlled engine. The problem is diagnosing the problem and then finding someone that sells the correct part to fix it.

 

No argument here !

 

Thanks all for the help/thoughts!

The truck has a new exhaust with converter included and the smog equip is all in place, all it would need is a new smog pump belt AFAIK, maybe a carb adjustment

That's what I plan on doing now after all your guys' advice, thanks again

Next question, would it be worth it to replace the cap/rotor before i go to test it? It already has had a carb rebuild, new plugs/wires, air/fuel filters and fuel pump

 

Pull it off and look at it. If it doesn't look good, replace it. Any miss-fires will foul up the emissions. You can also turn the idle mixture screws in farther than you normally would. Normally you adjust them for the highest smoothest idle or highest vacuum reading on a vacuum gauge. Once you do that, turn them in till the engine slows a little bit, that's called "lean best idle" adjustment. Once the tests are over you can turn them back out. It may give you a little hesitation when you hit the pedal, and the idle may be a little rougher than you like, but it may help it pass.

 

Ok, thanks Franklin