williemon

This is a little off topic as far as the car, but the engines and carbs are the same as well as the electronics I believe. I have an 87 Grand Prix with the LG4 305 and cc Q-jet. The 305 is toast and I have a 350 with 70K miles on it im pulling from a wreaked 86 caprice. The 350 is a 1996 goodwrench 350. The same one that Hot Rod did a build up report on a few years back. Its been running with a cc Q-jet just like on my LG4. What I want to know is, I plan on installing headers and a new intake and maybe a cam. This will be a daily driver so fuel mileage is important. I do want this to be a fun car also that I will take to the drag strip a few times a year. Where I live, they dont require emission testing. This swap I guess would not be emission legal anyway if I understand the laws correctly. SO my question is, what vacume hoses and emission devices like the smog pump would I need to leave in place? Id rather pull some off and cap some vacume fittings on the carb, but I dont know whats needed for it to run and tune itself properly. Any ideas? Also any advice as for as the computer goes? I thought I read somewhere that the 305 computer hinders a 350 somewhat. Any help would be good help.

87Formula4bbl

Let alone a 350, the computer hinders a 305 somewhat. HAHA.

Anyhow, you dont need to leave ANYTHING if you dont want. Pull it all. The only thing the computer needs is, essentially, the oxygen sensor, the mixture control solenoid and throttle position sensor in the carb. I've removed about everything (even have the EGR off and unplugged and the computer spits no code). Ya, unless I'm forgetting something, the computer reads TPS voltage and O2 sensor voltage, and determines the cycle the MCS gets to accurately (to an extent) adjust the fuel mixture. I have all the ports on my carb plugged except the front bowl vent (which I think ran to the canister) and the rear brake booster vacuum port. You can just stick some carb vacuum plugs on them and your set.

five7kid

iTrader: (14)

Absolute

Along with what was mentioned, the computer needs MAP and BAR, as well as the pulses from the distributor.

If you remove what isn't need by the computer, you're removing the EFE and A.I.R. Each have a vacuum line.

Well, the computer doesn't need the Evap, but you do.

87Formula4bbl

Sorry, didnt mean the computer itself, I was being vague, the thing about the computer is the timing curve. I'm actually a believer in keeping the computer equipment and carb/dist, I think its great, but I dont think the timing curve is great. Thats the thing that hinders performance.

five7kid

iTrader: (14)

Okay, just making sure.

A chip takes care of the timing curve.

83 Z28 HO

Do they make chips for cars like myn with a CCC q-jet? Or is it a newer q-jet?

five7kid

iTrader: (14)

Believe it or not, I got mine from JC Whitney. But, that was 4 years ago.

Jet Performance will cover it for you.

83 Z28 HO

Hmm, will have to ask. Thanks

Homer

iTrader: (1)

a CCC quadrajet has a MAP and BAR sensor? Where are they?

87Formula4bbl

MAP sensor is on drivers side, firewall. Has vacuum line running to it. Cant remember what color plug.
Bar sensor is on the passenger side, firewall. Has no vacuum line into it. Blue plug if I remember right (may vary by year?)