the never ending project. 71 super build

I'm not savvy enough to even come up with a useful suggestion. Is this the only carb you've been using or have you swapped in another to check if the issues disappear?

same carb. i bought it used from a reputable source who took it off a perfectly running bus because the owner wanted duel webers. it sat in his shop for a few weeks before he sold it to me. i stuck it on my old engine and it worked fine. no issues. then i found out that engine was shit and the carb sat in my garage for 8 years until i bolted it on this engine. it worked like shit so i threw a rebuild kit at it after completely dismantling it and soaking it in solvent over night. then blasting out every passage i could get to with carb cleaner. put it back together and bolted it back on my new long block.

i don't have another carb to try. i still own the original German carb from my original engine but it's not useable, the air volume control screw snapped off in it (i believe it managed to ether cross thread or get debris in the threads jambing it in there. and me being me i got pissed off and decided oh yeah? let me introduce you to my little friend, Dr. Bigger Screwdriver and snapped the head off) so im kinda screwed unless i want to go buy another carb. which i really don't. cause 1. im cheap. and 2. i really want duel webers (or at least EMPI HPMX's) but as of right now im to lazy to want to hassle with installing an electric fuel pump, fuel pump kill switch (cause you know, i live in CA) and a fuel pressure regulator. not to mention installing, adjusting, and tuning duel carbs.

got pissed this morning and threw my biggest jets in there. 140 main and 60 idle. took some timing out of it (went form 8 down to 5 at idle). still popping out the carb. but not nearly as bad. got it to at least come off idle without popping. then noticed the throttle shaft and nut were wet. sprayed them with carb cleaner. they dried out. played with the shaft, they were wet again. dip my finger in it, give it the smell test. yeap, gas. take the nut and arm off the shaft. wiggle it around, yeap, it has up an down play. put it back together, stripped the threads on the shaft :roll:

so now im thinking, do i bother trying to rebush that one(maybe pull the shaft/bushing out of my German carb? bet they don't fit), or just say the hell with it and buy a cheap carb.

edit:
just ordered a carb from CIP1. it's $90. we'll see what happens. it's got to be better than what iv got right?

Super_Randy wrote:

just ordered a carb from CIP1. it's $90. we'll see what happens. it's got to be better than what iv got right?

I think it's got to be a huge improvement. I don't remember the guy anymore but years ago paid for the carb guru over on samba to build one. It worked great but I'm sure that wouldn't be the case now :)

well, got the new carb out of the box this morning. blew all the passages out on the carb with carb cleaner. jetted it, 60 idle and 132.5 main (came with a 127 main and 55 idle. and optional 137 main and 60 idle) and it flat out won't start. got the base settings on all the screws. got the fast idle screw set as per every manual in existence and unless you're holding half throttle it wont idle. i cranked it so much i killed the battery. so now that's on the charger.

also noticed the fuel filter was empty this morning. so yeah, i have new problems forming and it's not even driveable :roll:

edit:
well, i got it idling. kinda. at like 400rpm so im back at ground zero! :roll:

Super_Randy wrote:

edit:
well, i got it idling. kinda. at like 400rpm so im back at ground zero! :roll:

What was causing it not to idle?

no idea! but i had just taken the battery off the charger so...

well today was interesting. pulled the idle jet. blew the piss out of it with about 60psi of air only to have it syphon all the gas in the float bowl down the carb throat even after i stopped blowing air. that was interesting. so now there's gas in the oil. :roll: ask me if i give a shit at this point. :evil:
the only thing iv noticed in messing with it this weekend is that it gives more effort to idle when it's on the battery charger. and no matter what, the volt gauge reads about 11 volts even though the battery (according to a fluke meter) reads 12.6volts.

im down to thinking, there's ether some kind of vacuum leak somewhere i haven't found yet. or iv got some kind of electrical issue (engine ground maybe?). or the generator just isn't supplying enough juice to run the ignition system. idk. im confused, short tempered and loosing interest.

pulled the carb off today. pulled all the jets and needles and everything out, blew the piss out of it with compressed air and carb cleaner. not sure if it actually cleaned out any debris. had a suspicious fleck on the throttle plate. don't know where it came from, don't know if it came from inside the carb or not.
changed the air correction jet. my old carb and my original German carb both had the same jet in it, the new carbs was different so i threw in an old one cause reasons.
attempted to cap off the intake manifold and blew compressed air down it in an attempt to look for vacuum leaks. didn't notice anything. figured why not and looked at the vacuum line with a screw in it plugging the vacuum port on the 3/4 intake manifold. that line ain't coming off! but i did get the screw out and coated it in RTV and stuffed it back in there globing it up around the end cause im really just throwing shit at the wall at this point.
swapped out the idle cut off solenoid cause i had one. again, throwing shit at the wall.
took the ground wire off the generator and wire brushed the living hell out of the eyelet and generator. again, more shit flung at the wall.

the floatbowl and fuel filter were close to empty when i opened the decklid this morning. never had that happen before. it's only been a week, usually they're both still full :? so that's concerning.

so tomorrow after that RTV has had time to cure ill go crank it up again and see what happens.

also wondering if the vent line on the gas tank is clogged... might try taking the gas cap off during testing...

You think maybe the vacuum at the tank pulled the fuel from the carb? That couldn't happen I don't think as the fuel comes in from the top at the needle.

im thinking the fuel filter is empty cause it's sucking back to the tank. there's no way the tank could suck the carb dry. that ether leaked or evaporated. don't know how, it's never happened before. the other option is that somehow the carb syphoned into the engine. don't know how that would be possible. but i have heard a glugging sound back there when i shut the car off. which would leave me to believe there's to much pressure and the needle is sticking open. but idk how it would drain the bowl down the carb throat if that were the case.

like i said im throwing shit at the wall at this point. im even considering getting out my old fuel pump (the one i couldn't find a while back) and putting it on there just to test. also considering changing the intake manifold gaskets. i used the original style metal ones. the heads are new and in theory are straight, the manifolds are over 50 years old with god knows how many heat cycles so... maybe paper gaskets?

well, i just tried it. still won't idle :evil: got it on the charger again cause why not. works great everywhere from 900rpm up to about 5000rpm. just won't f'ing idle :evil:

ok, had the battery on the charger all day. volt gauge in the car is now showing 12 volts again. fluke meter still shows the battery at 12.6. it cranks like crazy now, and i can read the time on the head unit again! haven't seen that sense i put the battery in. still won't idle. tomorrow (weather pending) im going to try my old fuel pump. if anything just for S&G.

ok, im not sick (had the flu back in Feb) and it's not raining, time to get back on it.
swapped out the fuel pump and lines, i know it has flow. i marked the level on the fuel filter to see if it's still draining.
when you crank it, it's back to backfiring out the carb :?
and i changed the connectors on the license plate light cause well just look at the pic. only now the light doesn't work. not sure if it worked before... probably should have checked it... i check the bulb and its fine, also check the fuses, so maybe corrosion?
so anyway, i did some stuff, but im not sure if it made any steps forward. productivity is overrated.

Super_Randy wrote:

... when you crank it, it's back to backfiring out the carb :?

Man... These carb & ignition issues are a PITA. :evil:
May be tackle the dual carb conversion right away?

Super_Randy wrote:

... changed the connectors on the license plate light ... only now the light doesn't work. not sure if it worked before... probably should have checked it... i check the bulb and its fine, also check the fuses, so maybe corrosion?

Hmm... Corrosion may be.
There's a "Y-connector" as well as two ground spade-connectors worth checking behind the tar board at the passenger side wheel well.

Also the wire from the engine compartment to the deck lid is sort of labyrinthine and well flexed.
May be a (hidden) cable break somewhere?

the light pigtail connectors are brown so they're pretty corroded. the other connectors should be ok. past experience tells me that if those have issues so do other lights and everything else is in working order. there is also a possibility the pigtail itself is bad, i got it out of a 77 parts car almost 20 years ago. i might just go ahead and replace it, i think they're pretty cheap and the rest of the car is fully rewired so why not do this to?

as for my backfiring and not idling issue. i have all new intake gaskets and copper gasket spray shit that is supposed to help with sealing and heat transfer. i also need to swap over to an alternator, pretty sure i have all the parts for that. ...minus maybe a fuel pump...
im also seriously starting to wonder if my firing order is off. im wondering what would happen if it was say 90 degrees off...

edit:
after doing some more research im wondering if its the spark plugs. i have NGK D7EA plugs and they're non resisted. i wonder if that's feeding "noise" into the ignition system :? the plugs i ran on my old engine are NGK BR6HS and they are resisted. i think im going to try replacing spark plugs.

That sounds like a plan.

I also wondered if a wrong firing order can cause the erratic idle.
Back in the day I had a 094 distributor that was 90° off.
It blew the air filter off... :D
But the engine refused to fire up.

i actually did blow the air filter off back before i replaced the carb :lol: i think that's what damaged the throttle linkage bushings causing them to seep fuel and cause a vacuum leak.
the only thing, it wont idle for shit. but above 1000rpm its fine. runs just like its supposed to.

as of right now my plan is to pick up new DR7EA plugs sometime this next week. swap them out next weekend and see what happens. rather or not they have any effect im going to rip the generator and intake manifold off and change the gaskets from the metal type to paper with the copper spray stuff. i might even lap the manifold end castings just for good measure. swap over to the alternator and pray like hell that maybe there was some kind of vacuum leak i haven't been able to pinpoint.

after that idk, maybe say the hell with it and redo the seats like i wanted to a year ago. at least then ill be comfortable while cranking the ignition over for no reason :lol:

DR7EA spark plugs acquired. we'll see if it makes any difference.

new plugs are in, car wont start. just backfires out the carb when you crank and crank and crank and crank and crank and crank it.

edit: alright, i got pissed, gave up, and pulled it all apart. generator and stand are off, intake manifold and carb are off. and low and behold there was fuel all over between the manifolds and heads so its pretty obvious they were leaking. getting the 3/4 side off was a bitch. one of the the nuts is almost impossible to get to with the engine in the car. idk how im going to get it back on... so the plan is now to lap the manifold ends and swap to paper gaskets with copper spray sealer. pressure test the center section cause why not. put it all back together with the alternator. and if that doesn't work, idk, buy a Chevelle and twin turbo LS swap it i guess. :?

Super_Randy wrote:

... there was fuel all over between the manifolds and heads so its pretty obvious they were leaking. getting the 3/4 side off was a bitch. one of the the nuts is almost impossible to get to with the engine in the car. idk how im going to get it back on...

I cut a metric 10/11 wench in half and ground down the outer arcs a bit for more clearance.
It also helps to remove the sidelong tar boards. But then they have to go back in later... :?
Anyway... The job requires loads of patience... :|

i got the manifold nut off with a short 13mm socket on a universal join to a 6" extension on a ratchet. it was at such an angel the universal joint didn't universal very well. i might see if we have any junk or leftover 13mm wrenches at work and cut one down like you did. i would imagine it would be easier.

Ah - I see... 13mm wrench/socket size nuts...
Sorry forgot to mention I use M8 11mm wrench size nuts.
Try to get some of these - they work wonders.
With the dual carb manifolds you'll love 'em even more. ;)

https://www.leadingedgeairfoils.com/hex-nut-m8-ws-11mm.html

Regarding the wrench...
To get an idea how I ground down the flanges of a STD wrench the one i modified looks like this one but cut in half...

lapped the manifolds and carb to manifold surface

put the fan on the alternator (stand was also lapped and is just thrown on to get it out of my way)

and because it was starting to rust, painted the center section of the manifold "satin granite"

i guess ill start putting it back together next weekend.

mostly thanks to a 1/4" drive ratchet, universal, and 6 point socket i managed to get the pain in the ass drivers side nut back on the manifold. doubt it's torqued anywhere near spec, but it's as tight as i can get it (thought i was going to break the universal).
passenger side went on pretty easy. oddly enough aside from getting the fan shroud lined up and back in place and that one manifold nut the whole thing went easier than i was expecting. hell even the fuel pump clears the alternator. which means somethings probably not going to work properly, cause that's how my life rolls.
anyway ill put the carb back on and tackle the wiring maybe tomorrow.