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Discussion Starter #1
1986 Bronco Rebuilt 302 EFI. 20 over with mild RV cam. Problems running rich and very sluggish (was told I can only use stock parts in the 86, due to the computer and the mass air flow. Is there any truth to this?). Does anyone know how to correct the problem?
 

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Man of endless projects
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theres alot it can be. you will be Speed Density unless someone did a MAF swap. Maf is pretty cam friendly to a certain point but SD is very particular and doesn't like even the mildest of cams.

did you check for codes? could be a number of reasons for running rich. wrong fuel pressure (bad fuel pressure regulator), old ignition components (plugs, wires, cap, rotor, coil). a bad MAP sensor could cause problems. bad o2/act/ect sensors. bad fuel injectors. list goes on and on but checking for codes helps us identify the problem
 

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If you covert to a mass air system you can then change cam, intake, heads with out problems. But I don't think broncos had mass air systems until 1993 or right around there. I know you can change a late 80s mustang over to mass air because they had speed density systems on them until 1989.
 

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This rebuild is from ground up so i have replaced every part all sensors, relays, ignition switch and cylinder, coil, dizzy, pick up, every part is new, lots of money, every nut and bolt, rebuild is for 16 year old son want dependable ride for him. so i should put an original cam in should cure problem i take it. if i switch to a 95 mass air flow set up i would more then likely have to put in bigger injectors. now getting less reliable for long hunting trips would this be correct. i just wanted a little lope and some more low end
 

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Discussion Starter #7
RV cam specs

lift Intake 0.448 exhaust 0.472
duration Intake 280 exhaust 289
lobe separation Intake 108 exhaust 116
I think a little to big? i dont know
 

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Discussion Starter #8
RV cam Specs

does anyone know if this cam would be ok for 86 302 EFI
lift intake 280 exhaust 289
duration intake 0.448 exhaust 0.472
lobe separation intake 108 exhaust 116
 

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Man of endless projects
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if you clicked on the link I gave...

For a good fuel injection truck cam:
intake duration @ 0.50" should be kept at or under 210
Gross valve lift should be kept under 0.500
Lobe seperation should be at or above 114°
 

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Eric
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does anyone know if this cam would be ok for 86 302 EFI
lift intake 280 exhaust 289
duration intake 0.448 exhaust 0.472
lobe separation intake 108 exhaust 116
Just a "heads-up"... your lift and duration figures are flip-flopped. Also, is that "advertised duration" or duration @ .050"? Seems like it would be "advertised duration". What are the specs at .050"?

Eric
 

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Discussion Starter #11
Thanks for the advice i purchased a stock cam will tear down and replace this weekend.I think i will stick with stuff pre 80's 0r 2000 and up much simpler.
 

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The Anti Yam!
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lobe separation intake 108 exhaust 116
This does not make sense. LSA is the separation of the intake and exhaust, there should not be a number for both.

Speed-Density does not like a cam with an LSA less than 114* If the cam you have now has an LSA of 114* or greater then it's not your problem and replacing it will just cost money and waste your time.

What is the cam part number?
 

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Discussion Starter #15
I didnt have time to wait no one in town had one two weeks out and need to finish for turkey season my son needs to take it all i have left is to paint fenders, hood and doors i will post all pics when done thank very much.
 

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Glad to see it worked out. You can always swap in a newer cam latter. Can't wait to see the finished product with a few turkey's on the hood/tailgate.
 
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