Eng swap on a 86 cutlass and rough idle

[BPTTONE420012]

http://mystarbrite.com/startron/

 

[olds307 and 403]

An Olds 403 is also a bolt in. The TH200 is weak, find a short tail TH350. The rear spiders will explode with abuse.

 

[LOCOGOMEZ]

change fuel filter and add a bottle of star tron enzyme fuel treatment... yuppp, snake oil... lol... i have found with the half dozen G-bodies i have owned, that none of them have liked this new ethanol added gas... the star tron enzyme fuel treatment helps to stop ethanol issues, staggering, sputtering, stalling, rough idle, etc... i use a small bottle to a half tank of gas and run it near empty then fill with 93 and it usually fixes the rough running... ONLY reason i even tried the stuff was because it came highly recommended, and its very clean burning... put a few drops on a piece of glass, light it, and let it burn off and you'll see there is NO residue... i use a bottle every few months when they start running funky...

You know i have never heard of this fuel treatment. Is it at a common parts store? Is it costly?

Fuel treatment cost from $2-$20.

If I am reading this correct you added the whole small bottle of additive correct? Or did you follow the instructions on the product. how long did it take for you to notice the difference? Thanks again for the info.

 

[BPTTONE420012]

first, i changed my fuel filter, then i used the whole small bottle on a half tank (i know directions say one ounce per whatever gallons but they also say it doesnt matter if you use more than recommended) and ran it damn near empty, then filled up, drove home and changed my fuel filter again... being as the filters are so cheap, and it only takes a couple min to change, i figured why not... besides the treatment helps break down deposits, and i figured a new filter before and after is a safe bet... didnt want an old filter clogging while i was driving, and then figured the treatment probably loosened a bunch of crap so the new one wasnt new anymore... i use the stuff every few months... a $20 investment is well worth it to me... i use it mostly in my 1983 3.8 229 malibu, it tends to start running rough after about 3 months, to the point where i have to double pedal at lights to keep her from stalling, and if i floor it the tires dont even try to break loose, and i try to brake stand, the rpms wont even get up high enough to get the tires to spin, but after a bottle of that i can punch it at a light and easily spin em, a brake stand will leave one hell of a smoke show... needless to say, i have gone through quite a few rear passenger tires on that car...

 

[UgotBronx]

Trani bolted right up and i already have a 3:73 rears upgrade on it from a while back.

The only issue i have is that everything runsa bit hotter which i dont care for so im swapping out the thermostat to a 180 and putting a heat plate under the carb

I swapped in an olds 350 and everything bolted right on. If you have any headers on the 307 that should migrate over as well.

as far as your current issues you can change parts out left and right and never find the problem(s) I changed from the Rochester to an edlebrock carb and that lasted 2 years, then issues again.

what about your transmission and rear end?

 

[LOCOGOMEZ]

 

[LOCOGOMEZ]

 

[CIDX1.25=LB TORQUE]

403 olds from late 70s early 80s is probably a bolt in. If you are looking for a little more go, 200-4r might be a problem. Flywheel might be hard to find and it might not like the torque of a 403.

I swapped in an olds 350 and everything bolted right on. If you have any headers on the 307 that should migrate over as well.

as far as your current issues you can change parts out left and right and never find the problem(s) I changed from the Rochester to an edlebrock carb and that lasted 2 years, then issues again.

what about your transmission and rear end?