2many280zzz

Gang~ I am a new user here and really appreciate the support! So first off, I have to thank everyone who replied to help, and specifically 'sblake01', for being a super sleuth in determining the direction in which to look for exactly the car I was working on (2 Z cars under one roof). AFM was the answer-Cheers! However cryptic the answer may have been for a complete layman (there are 7 pins on the AFM connector!), I love getting somewhat technical every now and then and using Haynes' wiring diagrams and the like to figure things out (AFM pins 39 & 36 normal open connect the fuel pump once running). A year ago I would have been like, "Which two wires??". Thanks for helping and challenging me at the same time. So to get to the real subject of this thread...BLASPHEMY!!! The FI to carb conversion was to a Holley 390 with Clifford intake :paranoid: I didn't wan't to say anything until I at least got it running and on the road. Actually, with very little adjustment, this setup kicks A$$!! I have only a minor flat spot between primary and secondary that could likely be adjusted out with different pump squirters. I know in theory, a carb for each cylinder (think ferrari) or two makes more sense. However, this is for basic, reliable transportation of a poor med student roughly 5+/- miles a day. Now if only we could get heat and locking doors working Thanks to everyone on here! ~Brannen

I was just telling Lynn that you are quite brilliant regarding this type of stuff. You are correct in that I am converting the '75. Fortunately every wire got labeled as I removed everything. I figured this failure was something to do with the stock setup that would have to be 'plugged back in' to something. The bridging makes sense now. Thank you! The '78 is next. Both are great cars with rather nightmareish injection systems. Threw some money at local 'Z experts':cross-eye: when I didn't live in town yet had no time to troubleshoot and fix it myself. They actually made things worse-jokers. Since, I have found the real experts in Tulsa who could actually teach me something. This fascinating info makes the coming morning much easier and a bit more fun. With great appreciation~ Brannen (and Lynn thanks you too...her Z)

Why would the fuel pump only operate when the key is in the 'start' position cranking it over? As soon as the Z starts, the fuel pump actually turns off. This is a new low pressure pump for carb conversion that works fine. This, verified by connecting to an external 12v power source. It ran great and I was even able to start dialing in the carb. What gives?

Mikey Firstly, congrats on the Z purchase. Currently ironing out a few of these sorts of kinks on a couple Zs we just picked up too. Sorry it's a not so timely yet lengthy response. Hopefully it will at least help you catch some typical problems and hassles quicker regarding an unknown Z. Working backwards- You are right on about the lug pattern. I wouldn't bother asking what wheel/tire combos fit though. Did you get to check the galleries and a few posts by searching? I went looking for those posts last weekend for a while and found a lot unanswered. Other replies just didn't strike me as the size/style I was going for either. Fitting wheels and tires is so personal that it seems to be a bit of trial and error for most people to get exactly what they want with a good fit. Keep in mind offsets, utilization of custom made spacers/adapter plates, rolling fenders a little and the conversion for keeping the speedo accurate (if you care about that). Find a little independent wheel & tire shop that admires your car and takes pride in the work they do to help troubleshoot what fits, looks good and works for you. Brakes If your pedal goes to the floor and you have to pump to get braking, it's maybe one of two things. The worst is that the diaphragm in the booster could be going out. It gets worse over time until there's virtually no apparent braking left at all.:eek: It's !$$$! on some cars like a '66 Polara-don't know about the Z. More likely, however, there's just air in the brake line that needs to be bled out. Just purchasing the car and not knowing a lot of history, bleeding the nasty old fluid out of the brake sytem would be a wise thing anyways. Good chance it will solve your soft pedal problem and also lead you to other immediate threats to good braking. A friend in college had a weird brake failure that was pretty scary. Timing/Driveability The book can be fairly helpful somtimes even if just as a good reference. Someone once suggested even getting both clymer and haynes because one filled in the gaps of the other Soooo, the timing accordong to Haynes for a 240 manual with no emmisions control says static ignition timing at 17 degrees @ 650 rpm with a 6 degree centrifugal advance from 450-1000rpm and 5.5 degrees vacuum advance from 3.94 Hg to 9.6 Hg (by the way, vaccum lines and all can be a total mess on a Z-use a gauge and check everything and rule it out). I'm not as familiar with the 'preferred' timing that all the different Z setups liked, but I always personally ran more advanced on my iron Buick 350. More power, better fuel economy, less sputtering when cold, etc. Drawbacks are harder starting, hard on starter and electrical system itself, need to run premium fuel, and worst of all the chance of tossing a rod through the oil pan. Nine years and forty-some-thousand miles and no problems though. Well good luck, there's often a lot of work that can be done to get 'em running nice. We'll be here for you. Brannen

Just converted from FI to carbs on a late '75 280. It runs fantastic until the float runs out of fuel. Pull the coil, crank starter, fill the bowl, plug in coil, repeat. Checked fuel flow when the car is actually running and there is NOTHING. Switched to a low pressure fuel pump that flows nicely but only when the ignition switch is cranking the starter. Apparently I've missed something in this conversion that is critical for telling the fuel pump to continue running when the engine is on, not just turning over prior to start. Any help is hugely appreciated. Thanks a million!

Hey gang~ Am I ever glad to be here! What a great group of Z fanatics. I hope to get to know some of you in time. I'm excited to go to some events in the coming years. There are such great stories behind these cars. Here's a tidbit of mine. I'm Brannen from Denver/Tulsa. I know, I know...it's a long commute. I work in Colorado through the week as an Eyecare consultant for Carl Zeiss optics and my other half (Lynn) is in med school @ OSU. Cool girl (and brilliant); talked herself into a beautifully customized, restored Z car before we moved to Tulsa. I had a pretty sweet '77 280 back in college but couldn't afford to fix all that plagued it. It was time to catch the car disease all over again. Lynn, concerned that I would get the 'pick of the litter', ended up with the 280 I personally had my eye on for months before I even knew it was going up for sale. I had to get the ugliest (but largely rust-free) thing you've ever seen so as not to seem greedy and self serving. I now, however, have the latitude to build this into the most extraordinary example I could ever have imagined. Stay tuned~ Brannen