4 replies to this topic

[1986civicwagon]

Hey guys, I heard around the net this was the place to go for great info on 80's hondas.

I'll start out with the background....

Bought the car for $500 on craigslist, the guy picked it up from the original owner for his son, but didn't know anything about carbs, so I bought it (everything else works great). I was getting a lean misfire at idle, wouldnt really idle at all under 1000, and missed until about 2500, then clear as a bell on up. I did drive it, good power through the gears...or any time with a load on the engine, but way too lean at idle. Fuel seemed to dump out of the primary veturi, not atomized but like a broken liquid stream, and the aux butterfly was wet with fuel. The choke wouldnt open, only pull off, and thats why it would run at all being so lean, you manually open it...and it would die. So knowing it was lean I got a carb kit, rebuilt it, put it on...would run at all without pumping the accel constantly and if it dropped below 2000 it would die anyway. Took it off and cleaned it again...same thing, I did get more discolored carb cleaner as I sprayed the passages this time, but they were all clear when I assembled it back last night. This morning, and the first time I put it back on the car (both times) I noticed I had NO fuel coming from the aux bore. BONE DRY. So, I'm guessing I blocked an important passage somehow. I did use compressed air to blow out the passages, but not full blast through the holes...as I have heard you can permanently seat enclosed check balls. I drove 100 miles into South Carolina to get a carb listed in the junkyard database, but it was complete junk, as the hood was left up and it was full of water...I was rather angry with them, as they knew I was coming from Charlotte. Is it even worth it to try and find another core and rebuild it? What about National Carbs, 200 bucks for a reman unit...has anyone had luck with that?

All I would like to know is if my carb is done...or what should I do next?

Thanks guys.

[letank]

I was getting a lean misfire at idle, wouldnt really idle at all under 1000, and missed until about 2500, then clear as a bell on up. I did drive it, good power through the gears...or any time with a load on the engine, but way too lean at idle. Fuel seemed to dump out of the primary veturi, not atomized but like a broken liquid stream, and the aux butterfly was wet with fuel. The choke wouldnt open, only pull off, and thats why it would run at all being so lean, you manually open it...and it would die. So knowing it was lean I got a carb kit, rebuilt it, put it on...would run at all without pumping the accel constantly and if it dropped below 2000 it would die anyway. Took it off and cleaned it again...same thing, I did get more discolored carb cleaner as I sprayed the passages this time, but they were all clear when I assembled it back last night. This morning, and the first time I put it back on the car (both times) I noticed I had NO fuel coming from the aux bore. BONE DRY. So, I'm guessing I blocked an important passage somehow. I did use compressed air to blow out the passages, but not full blast through the holes...as I have heard you can permanently seat enclosed check balls. I drove 100 miles into South Carolina to get a carb listed in the junkyard database, but it was complete junk, as the hood was left up and it was full of water...I was rather angry with them, as they knew I was coming from Charlotte. Is it even worth it to try and find another core and rebuild it? What about National Carbs, 200 bucks for a reman unit...has anyone had luck with that?

All I would like to know is if my carb is done...or what should I do next?

Thanks guys.

Welcome to the asylum.
The first point is that you are not sure what the problem is... You mentioned lean idle, but state that the choke was not opened all the way.... so we are more rich than lean.... The real point is that it was not idling under 1000rpm, and was misfiring up to the 2k, then had power....The rebuilt carb kit did not solve your problem, as you may have uncovered other issues, and now you are wondering if it is worth buying a rebuilt carb.

These carbs are a real pita, because they are more like air metering systems, with too many controlled valves.... hence the devac that some are doing using a weber, if you have no smog check, or at least no visual that is a way to do it.... but there is no warranty that it will work.

Back to your question, if the car is really in good shape, it may be worth the $200 rebuilt carb... making sure that there is someone to ask questions or that the carb has been tested or come w some return or exchange policy -which I doubt, but you may ask-.... the big issue is that the power valve does not have any listed replacement for it and we hope that the rebuilt carb has a new power valve.

Back to simple solutions, you could have a big vacuum leak, with so many hoses some can crack, especially in the back, and under the intake manifold you have 2 big hoses that can create issues, I failed smog for very high Nox in Cal, obtained a waiver, and found out many month later when I had to replace the alternator -easier done from underneath, w car on block- that when I sprayed brake cleaner that my idle went high up, which I could not do when spraying from above... I fixed the faulty hose... a real pain.... because all the valves around it... but you can temporarily put a clamp for testing purposes.

So visually check all those hoses and their tightness. The one for the power valve above and in the rear will show their age. I replaced them on the hatchback along w the big one mentioned above,.... I have more power.... and will see when I am due for smog.

These carbs are also known for a failling isolator or carb to intake manifold gasket.... I had an 86 bought brand new.... and we had the faulty gasket... but it was such a pain to do, that I lived with it....high idle in the morning... but after a few minutes warm up, it was fine... I did not feel like dealing w the spaghettis of vacuum tubing....

Let us know what you decide.

[1986civicwagon]

Thanks so much for your reply! I'll address your input from the top down

1. What I meant by lean idle and choke not opened was the fact that the only way for it to run was without the choke open, if you pushed your fingers over it to close it, the idle would literally skyrocket...upwards of 3k.
2. I'll put it this way, the carb actually idled before both rebuild attempts...now it struggles to run without pumping the accel pedal at all.
3. Devac is one option, but they are still doing visuals here in NC and for some odd reason they are cracking down on these old cars...also I don't want to decrease my fuel mileage, that's the only reason I bought the car!
4. National Carbs is a huge company, after core return my total would be $231.70, but I'm not giving up quite yet.
5. While the carb was off the first time I did replace those 2 big lines, and I sprayed carb cleaner around everywhere when we were attempting to locate the vacuum leak.
6. The insulator looks fine, with a few cracks where the corners meet, but nothing getting into the sealing surface or throttle bores. Now, the O-ring seals are iffy, I have only found a replacement for the top one, not the bottom.

I will soak the carb in Pine-Sol today for 24 hours, I'll assemble it, slap it back on, and if it still does the same thing ill check to make sure everything is hooked up in the right spot (for the 346th time ha) and let you guys know what happens.

Thanks!

[letank]

1. What I meant by lean idle and choke not opened was the fact that the only way for it to run was without the choke open, if you pushed your fingers over it to close it, the idle would literally skyrocket...upwards of 3k.

Still confused with the second part of that sentence..... in relation to the first part.... :if" it run without the choke open"... so it runs w the choke flapper closed.... then you said that the idle would skyrocket if you pushed to close the flapper.... there is an opposite statement.... sorry... did I miss something....?


So 1) does it idle (even poorly) w the flapper closed ?


And back to your issue, if it is bone dry... there is some dirt in one of the passage or a piece of o-ring ...

[1986civicwagon]

I'll start over...

When I crank it up, the choke pull off will open the choke baffle a quarter inch or so. If i put pressure on it and close it almost all the way off with the engine up to temp, the idle speeds up, indicating a lean idle mixture. Now, if I open the choke baffle all the way open with the engine up to temp, it will die, also indicating a lean mixture. It also runs a little hot (a little over halfway on the gauge but less than 2/3rds) in 65 degree weather...indicating a lean mixture and/or over-advanced timing.

I'm hoping I make batter sense now, I'm only 22 but I've been working on cars since I could hold a wrench. I know what I mean, but it's hard to explain sometimes haha.

Edited by 1986civicwagon, 21 April 2012 - 03:22 PM.