I want to start by saying, I'm mechanically inclined...but definitely not a mechanic. I just picked up a 80 sr5 and cant get it to smog. It blows high co at 2500. In my quest to get it to smog, i replaced all of the soft lines in the fuel delivery and evap system, along with all of the vacuum lines. I replaced them one at a time so i didnt mix anything up. So here's my issue. I took it down to the smog station for a second pre-smog(which it failed), and it ran fine on the way down there. On the way back, after two or so miles, it started chugging really bad at about 2500 rpm. almost to the point where it wanted to die out. Its a rebuilt motor that sat for a few years in the previous owners garage. Any ideas at all would be VERY helpful!

 

Sounds like either weak spark or weak fuel. Spark is more likely. Fuel pump usually either quits or works. The cool could be getting weak making it harder to pass smog, and effectively burn the a/f mix. I would swap to a better than stock one like an accel super coil or an msd blaster 2. Unless you changed it and I missed that lol.

 

I didn't change the coil, that is probably my next stab at it. I kinda feel like I'm throwing s#*t at the wall to see what sticks. Im pretty sure I'm going to be changing A LOT of components on this thing, but its a labor of love. Thanks for responding!

 

Don't worry, if you plan to keep it its always great to have an engine covered in fresh parts. Most of it probably hasn't been changed in a decade or more. Truck just wants some lovin'

 

Your blowing high co2 carbon dioxide ? . At 2500What's the condition of your catalytic converter rebuilt motor was cat changed as well ...old oil burning motors are tuff on cats they clog them up Chugging and heaving at a steady rpm is a sign of a low flowing cat . And there are other symptoms that can cause that as well how was your hydro carbon test results

 

Cat looks almost new, though it may be clogged. The high reading is Carbon Monoxide. Passing is 2.0 and my 80' is pushing 4.30 @ 2500 rpm. Hc is 103 at idle and 70 at 2500.

 

That's so true. My plans for this girl include some very extensive restoration/ repairs anyway. I want to make this baby run well, and look sweet... its just the beginning of a long romance between my 80' and I.

 

Update on the 80'... Have a rebuilt Asian carb on the way. Going to swap out the old one and see how it runs.

 

Dropped in the new rebuilt carb. Now I need an actual mechanic to tune it for me. It runs for a few minutes, then dies out. It'll start every time, but the mixture is way off, and I have to re check all those damn vacuum lines to see if I may have crossed up one or more.

 

If your stock aisin doesn't workout and you still want to pass smog, you can do what I did and use a weber 32/36 and modifying the stock air filter so you can pass the visual for the smog. I also had the vacuum lines falsely hooked up so that it looked stock. It passed with flying colors.

 

i plan on putting a weber on in the future, but it ran ok with the old carb, so im going to see if i can get a few miles out of this one. I'm going to get a little help with it to get it on the road. Then the games will begin. Ill end up going through the whole thing.