QUOTE(JRust @ Jun 30 2007, 12:13 AM)
It's next weekend. The 6th,7th & 8th at PIR. I'm curious about the extra smog stuff on my motor. Anyonw know if I can just pull the pump & plug the rest? Whats the best way to handle that?
Hey Jamie...I put a 76 smog 2.0 in my 74 and stripped the smog. Here are some things you can ponder:
I don't know how anything about the Oregon smog laws and don't want to...but if you want to remove it this is what I would do.
First, I would remove it all, but save it for "just in case."
Pull the smog pump or at least pull the belt that drives it (biggest hp robber)
Pull all the piping that is connected to the heads. The easiest way to plug the heads is with 3/8 brass/bronze caps from the plumbing store. The thread, which is standard 1/8 pipe thread is close enough that it will thread on nicely without any damage to the steel injector head nozzles and seal.
Now, threre's a good chance that your 75 will have some low end dead spots, surging idle or some bucking due to the fuel mixture being to lean (75 & 76 motors). A easy way to solve this is to add some resitance in-line (in series) with the TS2 (head sensor) which will slightly richen your fuel mixture and make a world of difference.
Determining how much resistance: You will probably have to add around 270 ohms and anywhere up to 500 ohms. I added 470 to find where my motor ran best (76 2.0). A lot depends on your motor modifications and exhaust. Hopefully you can throw away your 75 exhaust and backdate with 74 or older---big difference in flow and weight.
You can buy the resistors at Radio Shack for $1 apiece. One way is too buy a few 100 ohm resistors and a 50 and soder some quick connect connectors on each end. This way you can keep adding more resistance and do the "drive test."
Another way is to buy an adjustable potentiometer (0-1000 ohms) ($3) and wire in series with TS2. With a meter set the pot for about 300 ohms and drive it. You can keep adjusting the pot until you find your "sweet spot" and then measure the pots resistance to know how many resistors you need exactly to put in line permanently.
FYI...when you get up near 500 ohms, your fuel mixture will be enriched across all driving speeds. Here is a great chart from Brad's site that shows the effect of resistance.
PS Don't over anyalyze the whole process...you might just add 300 ohms and drive it and see.
You should not have to play with the MPS or ECU knob...in fact just leave them alone.
Good Luck....PS You might also consider venting your valve covers or adding vents to your heads (many 75 and 76 motors have only one or no vents in the heads). Adding a puke box and venting the heads wll help reduce those famous 914 oil leaks and keep those blow by gasses from being reburned...of course that's another story.