Anyone tried the Holley 4-barrel Carb Conversion?

[rossiz]

I saw this on the Arizona Z Car site

manifold.html

It sure looks tempting, as I'm not totally comfortable with the fuel injection on my '78 280z... the hot-start issues, leaky injectors, high-pressure system, sketchy electrical connections, multiple sensors, AFM, etc. shake my confidence as my car is my DD and I need to be able to count on it to start/run when I turn the key.

I've been following the HellFire thread, which sounds promising, but I worry about going further into the techno-abyss.

I know some say the FI system is solid, but the allure of a simple, single carb (no synchronizing, no SU woes) is strong. The fact is, I actually understand carbs and can fettle them if needed - not so much with the electronic wizardry...

I'd love to hear if anyone has tried this setup and what their impressions are. I will drive the car all year round (in Seattle, so no extreme cold/snow issues) and just want a dependable car that runs well all the time. I currently have stock exhaust, but will do a custom 2.5" from the stock manifold back into a glass-pack resonator then a magnaflow at the rear.

Thanks in advance,

Geoff

[Walter Moore]

Some people have:

http://www.classiczcars.com/forums/carburetors-s30/51440-holley-4bbl-performance.html

http://www.classiczcars.com/forums/carburetors-s30/45500-holley-4-barrel-question.html

http://www.classiczcars.com/forums/carburetors-s30/41474-holley-setup.html

http://www.classiczcars.com/forums/open-s30-z-discussions/29299-blasphemy-some-say-you-guys-great.html

Etc...

I personally have no opinion.

[Mark Maras]

Go for it. I can understand your desire for a trouble free DD. I drove my 71 daily for 23 years with SUs and it was the most reliable car I ever owned but I did take care of the carbs with regular maintenance. It was all new and fun back then. The Holley will give you everything you want without the tinkering. I've never seen the air filter arrangement for this mod, there can't be much room between the carb and the hood.

[FastWoman]

If you HAVE TO go to carburetion, which you probably can guess I feel is a big mistake, for God's sake, stay away from the Holley 4-barrel! I slapped a Holley on our boat, and it worked great for a season. Then the ethanol gas got the better of it. So I replaced it with another Holley, which was good for a season. Then I rebuilt the first one, and it ran like @#$%. Then I rebuilt the second, and a fuel plug started leaking. I brazed over it and patched it back together, but the little accelerator pump rubber doodad ripped. Expensive little piece of rubber! The carb still didn't work right. So I paid a lot of money to have it professionally rebuilt. It ran OK, but not great. Then we sold the boat, and that fixed the problem.

The Holley is the WORST carb I've ever rebuilt, and being a child of the 60's, I've rebuilt many.

FAIW, the SU looks like a really nice design. I think I'd try a nice pair of those.

Better still, give the EFI half a chance.

[rossiz]

well, apologies to all for opening up this wound...

i had NO IDEA how much this topic had been discussed and how many tender nerves there were regarding this piece of equipment. i suppose i should have done more searching before stuffing my newbie foot down my gullet. lots of good info though, and i've learned quite a bit in the last few hours reading through a few carb threads. in the end, it seems there are enough completely contradicting opinions, stories, examples, etc. that unless i actually get to see and drive in a 280 w/this setup it's still up for grabs whether i'll actually gain or lose.

as far as giving the FI half a chance, i guess i'm still shaken from the ride home in a tow truck a week or two after i had the car up and running due to (i think) the sensors in the thermostat housing and a cold start valve that flooded my engine to the point of ruining a brand new set of plugs - and i was completely helpless, couldn't do a thing other than call AAA and wait 2 hrs for the ride of shame. the other night i was going to take my teenage daughter to another appointment and she winced, saying "pleeeease can we NOT take the z? i just can't handle stalling again!". talk about a knife to the heart for this old guy...

i spent my youth hooning around in old heaps and never thought twice about it, knowing that with a screwdriver, pliers, some tape, wire and a broken piece of hacksaw blade (to gap points, of course) i could always get it started/keep it running. the FI system just seems so friggin binary - it either works, or i'm SOL on the side of the road, head in the footwell, arse in the air fiddling with multi-pin connectors and uttering curses in vain attempts to trace a mysterious problem that i can neither see nor hear.

truth be told, the car is running really well right now, and i've ordered a new bosch fuel pump check valve (thanks cap'n O) which i'm hoping will keep my system pressurized and help w/the intermittent starting issues, which is really the last big issue that i see. but then, that's what i was thinking before the big ride w/AAA...

i just saw the big carb option and thought dreamily how this could simplify sooo much under the bonnet and maybe magically solve all the problems in one shot. i'd really like to not be worried about being "that guy" you hear about on the traffic report that's causing the rush-hour jam by being stalled dead at the freeway on-ramp so i could focus on other mods, and driving it (exhaust, suspension, wheels/tires are on the short list). seemed like a carb could be a back-up plan in case the FI thing just didn't work out.

[FastWoman]

Rossiz, if your EFI setup is running great right now, I'd just do what's necessary to keep it running that way. That means cleaning or replacing every EFI connector under the hood. (They're all available on ebay.) As long as you do that, your EFI will keep running about the same.

As for the hot restart problem, the new check valve will probably take care of most of the problem.

I can't help you with the teenage daughter problem. I once had a gorgeous '66 Mustang, and my kids (both boys) were mortified to be seen in it. It was "old" -- not like one of those nice SUVs that respectable people drove. Go figure. Much later, my stepson, then a 20-something young man, began to appreciate my 'Stang, but alas it was time to sell it and move on to a Z, which is what I really should have been driving all along. But with a young/teenage kid, if the car doesn't immediately and effortlessly "turn on" when you turn the key, then it's deemed an embarrassing piece of junk.

Anyway, assuming you resolve most of the hot restart issue, if you have such an incident, raise the hood to let the engine cool. Try the key again in 2-5 min, and you'll be on your way. Wiggle a few things confidently and authoritatively while you're waiting, and you'll look like a hero. You can also wire a switch to your fuel pump relay with three positions: First position (momentary), you feed +12 to the relay to run the pump and prime the fuel rail. Second position, the pump is connected normally. Third position interrupts the 12V to the relay, so that the pump won't run. In the third position (momentary), you can crank your engine without fuel to clear any flooded cylinders.

Oh, and FAIW, the hot restart problem won't happen until the car has been sitting for at least 10 min. So if you stall your engine for some reason, you can restart it. You'll find the only time you have a hot restart problem is when the car is parked, so you won't be in a bad position.

Edited April 1, 2014 by FastWoman

[Stanley]

Do you need to smog the car in WA, and if so are they cool with modifications? I read that in CA if you modify anything and put a CAT and get the emissions even lower than required for stock, that's still a violation.

F.I. is big mystery to me. Looks so complicated, but I've seen some F.I. setups on Datsun at car shows that look simple and beautiful. SU's also work good and are very simple. Not much in there to get confused about. Only problem is some parts are hard to locate, and some parts (nozzles and floats) cost five times as much as they did in 2007.

[Captain_Zeros]

Anything over 25 years old is smog exempt in Washington :tapemouth

[St.stephen]

Rossiz here is a link to a 77 page manual for the L jetronic fuel injection system used in the 280Z. The manual is for the 75 but later years aren't much different at all. While the fuel injection can seem intimidating this manual should make things a little more clear for you. I printed it out and keep it on the shelf in a binder and reference it rather frequently if a problem arises. Hope this helps. Regards, Kevin

http://www.4moores.com/280z/files/280zfuelinjectionbook.pdf

[an_unusual_eye]

i'm not sure why i'm posting, as i have nothing negative to say.

my '78 had a holley 4 barrel, and so did my late '71 240z. both were installed before i owned the cars, and both performed flawlessly (really) during my time with the cars. THAT SAID. even as a DD, i generally believe that unless something is presenting insurmountable problems or something else offers significant drivability benefits (i.e. 5 speed transmission)... sticking with original equipment and suffering through the initial turmoil gets my vote. if the end of the FI tunnel may be in sight, i'd probably stay the course. if i were to modify to carbs, i'd probably go with a fresh set of SUs. full circle, i had great power, service, and even fuel economy (well... almost great) from the 4bbl set-ups. full disclosure as it applies to FW's negative experience though ~ i never ran ethanol tainted fuel in either 4bbl z. best ~ rob.

Edited April 2, 2014 by an_unusual_eye

[rossiz]

wow, you guys rock!

to FW: i greatly appreciate the commiseration re: the teenager. my sons (there are 4 of them) all think the z is cool, but mostly they're interest lies in trying to get me to lend it to them for the prom - not happening. i will block out some time this weekend to tear into the electrical connections - i've already replaced all of the FI plugs and half the others during sensor replacement, but i haven't done a thorough walk through the entire system. sage advice, no doubt i will find more dodgey bits that need a bit of love & dielectric grease...

to St S: thank you SO MUCH for the link - the FI book is downloaded and i'll be poring over it for the next few nights. i had looked into the FI Bible, but i think it was just too much too quickly for me and i found myself glazing over and falling behind - like sitting in a math class that's a level too advanced. maybe after your book i'll be ready for it. better yet, maybe after cleaning up connections and replacing the check valve and main injectors, i won't NEED to deal with it!

to Unusual: agreed, i'll stay the course and see it through. my dad used to say "with an old car, it's always somethin' - until you replace everything, then you have a new car!" i'm pretty close to there on the FI system at this point...

[SteveJ]

IMHO the fuel injection system in the Z isn't that difficult to get into a good working order. I've helped a few people get their systems working correctly electrically just by reading the manual and guiding them on troubleshooting. I have never even worked on the Z fuel injection.