bad warming up

[Tailfin]

Speaking of that rich bit...is there any way to offset it? I'm not sure I entirely understand the principle of the float and how the level directly affects mixture (I would hope the jets were always submerged anyway lol)...but is it possible to just lean the mixture that way?...or I know there's the air/fuel mixture screw...but umm...on mine, it doesn't look like a screw...just a fixed piece with no flat, phillips, torx or any sort of medium for me to be allowed to turn it...sheesh.

Anyway, thread-jacking aside... There must be a reason why the car won't idle properly. I don't understand why the fast idle was ever there. I have the idle set to around 1000 or maybe just a smigin more and it runs pretty steadily whehter it's just started or warmed up. The only reason I don't set it a little lower is it occassionally wants to stall after it's warmed up (go figure) when you come to a stop with it in gear. Again, I also took that ludicrous black box out and gave it a good field goal worthy punt...and I haven't tested this in the sub-zero depth of winter, but still...

Might be slight wear on a lot of parts combined because of age or poor maintenance...like slightly worn ignition parts, carbon buildup in the engine, carb or throttle blades, the already mentioned vacuum leak(s), gasket leaks, fuel filters, valve clearance, timing off a bit, clogged exhaust, yada yada yada...(I know you've probably done some of this...just listed everything that came to mind). Good luck.

[A18A]

Speaking of that rich bit...is there any way to offset it? I'm not sure I entirely understand the principle of the float and how the level directly affects mixture (I would hope the jets were always submerged anyway lol)...but is it possible to just lean the mixture that way?...or I know there's the air/fuel mixture screw...but umm...on mine, it doesn't look like a screw...just a fixed piece with no flat, phillips, torx or any sort of medium for me to be allowed to turn it...sheesh.

would that be the a/f screw thats painted yellow on the top hat by the fuel line?


i also noticed just before a leak into the intake manifold, i replaced 2 hoses that go into the intake, seams to run a little bit better. im not too sure on how it is now but cold idles are about 1800 - 2200 rpm gonna hope it drops when its warm. my dad is saying something about a fast idle cam, any ideas were it is? and how to disconnect it? i would prefer a pic description but if not, ya have to use a strong description to make me understand lol.


oh yeah, all the things ive done so far:

replaced head gasket
cleaned pistons and valves/head
replaced plugs
replaced wires
replaced coil
replaced dizzy (with good cap)
replaced oil
replaced oil filter
replaced boh fuel filters
replaced a few hoses
replaced some gasket
inspected other hoses and gaskets
perfected valve timing along with ignition timing with timing light
prolly some other stuff i cant remember right now too



and the small list of problems i have right now:
dieseling
high idle
random backfires from the carb

[Tailfin]

No, that screw is the float adjustment. That would be good to check too though. With the engine running, make sure the fuel level is in the middle of the float inspection window. You'll see it just below where that screw is on the driver's side. If it's not in the middle, you need to adjust that screw... I believe turning it clockwise will lean the mixture (drop the fuel level) and vice versa. If you adjust it, do not turn it more than 1/8 of a turn every 15 seconds (as per the service manual there).

The air/fuel mixture screw is in a recessed hole on the backside of the carb...I wouldn't actually worry about that, I was just posting a tangent, if you will. From what I've read on the how-to's on this site, that is factory set, and there's no need to mess with it...so it shouldn't be a "problem."

The fast idle cam and unloader, etc... is what I mentioned above. I would take a pic for you, but that flood up here ate my digital camera... As I mentioned, the throttle arm rests against the fast idle cam. Take the air cover off and look from the passenger side of the carb. You will see the accelerator cable coming to that area...attached to the throttle arm, which it pulls as you press the accelerator. You can move that throttle arm manually to see how the linkage works there. Look closely, and you'll see a little object that the throttle arm rests against when it's let go. That's the fast idle cam... Just a little circular piece with steps on it, which are the increments of the fast idle as the car warms up. As it does, more vacuum is designed to be directed to the fast idle unloader, which will pull that cam up so the arm can rest against the stop or idle screw...I say "designed" because it has become apparent to me that that's about as far as it goes with these things. The fast idle unloader is the thing with two vacuum hoses going to it (not the choke opener), and is mounted on the back side of the carb. On mine, it's black, unlike other components attached to the carb. The lever/diaphram that comes out of that unloader is attached to a linkage, in turn which interacts with the choke, as well as pulling that cam out of the way (you won't really see this much clearly without taking the choke opener and that linkage off the carb, but that's ok :-P). Because it interacts with the choke (there is a little rod with cotter pins holding that linkage to the choke linkage), if the fast idle cam is "held" out of the way permanently (this is if you're trying to direct vacuum constantly to it, bypassing the thermovalve, or just physically tying it back somehow), then the choke plate will not close all the way (which in a way makes sense, since it shouldn't need to if the engine were warm). This is where I took that connecting rod between the linkages out and removed the whole fast idle system lol... You may not choose to do that, but there are your options, and that's how it works.

[2oodoor]

weather change ?
I hate these carbs, the fast idle unloader is separate from choke unloader. wtf. if you have checked all like you said here already, what I did on mine was crank it without choke, eventually was going to put HELP brand generic manual choke kit just to pull the blade and hold the idle up with my foot.
I have the kit still if you want it, it would be better just to get one there in NZ. I found a weber before i ever got a chance to put the cable on. The kit here was like sevan bucks at auto zone, you could use one from a junker, if you have junk yards you may even find a weber on something , they used them on a lot of euro cars factory, all you would have to buy is adapter for honda,l and make linkage.just for basics. If your carb runs good otherwise I would just take off all that choke hardware and make a manual cable and foot your fast idle. Probably too cold to crankit without closing the blade at all...really ghetto would be using lawn mower throttle or golf cart choke cable with housinng mount it somewhere maybe on the console or just under dash.

[Tailfin]

Ack, and now that I think of it, did you investigate the carburetor itself? I don't suggest rebuilding every part, but you can take just the screws out and remove the top hat/air horn part of it, and get an idea of what the gaskets are like just from that. When I rebuilt mine, that was the only gasket that looked crappy. Other than that, check out the booster venturi...which are the smaller tubes within the barrels of the carburetor...make sure they do not wiggle. If they do, you need to take the screw out of the side that holds it in place, replace the o-ring, and screw it back in snugly. I'm thinking this is possible to do with the carb still on the manifold, but a pain in the arse... If they're secure though, don't worry too much about it.

[A18A]

yeah them 2 thingies are in nice and tight

[A18A]

yay progress is comming along, we got it to idle at around 750 - 900 which is nice and healthy, it no longer has a rediculous high idle, and had it running very smoothly, like no putt putt outta the exhaust and bearly any pressure, and the engine wasnt shaking so much....... but the smoothness came back again, we just adjusting whatever we can to get it running smooth. the pre-ignition wasnt so bad either, but its still bad. soi all that remains other than the very fine tuning of the carb is deisiling, and its all good

i have no idea what i would have done without you guys thanks alot

[A20A1]

The higher the float level, the more the gas will flow without the need for pressure drop inside the venturies. In fact if you have the float level above the venturi exit fuel will constantly spill out the venturies, just like a cup that was overfilled. Imagine the float bowl as part of the cup and the exit in the venturi as the rim of the cup... too high a float level and it overflows.

[A18A]

oo i checked the float level, its just a bit rich thats all, still between the marks though. we got it running smooth again, idling nice and low, 750 - 1000 is what it idles at. only small problem left now is minor, we'll fix that tomorrow and is it normal for $6 petrol to last about 2 - 3 hours running at avg of 1500 - 200rpm? and it takes a little while to respon under 2krpm but thats ok, and a little bit of stalling which is easy. other than that it runs fiiiiiine

[Tailfin]

The higher the float level, the more the gas will flow without the need for pressure drop inside the venturies. In fact if you have the float level above the venturi exit fuel will constantly spill out the venturies, just like a cup that was overfilled. Imagine the float bowl as part of the cup and the exit in the venturi as the rim of the cup... too high a float level and it overflows.

Cool...makes sense... Now my only other question goes back to that how-to in the carb vacuum removal...you mention plugging the vents...how come? I guess I can see that simply making it a bit rich, but I'd think you would still want the pressure to equalize somehow...

Overdosed, good to hear. Don't go futzing too much if it's working now lol...but if it's still dieseling badly, then air is getting in there somehow, just keep that in mind. First thing I'd check is the choke return spring. Push the choke plate down, and it should return to its previous position. Like I said, mine was broken, so now I've got a ghetto throttle return spring to the firewall (attached to the little arm there that moves with the choke plate).

Anyhoo, if you've been doing this with the air cleaner off, you might see an improvement with it back on as well. If you did anything to the vacuum, make sure you plug the holes going into the air filter housing...or if you didn't, just double check that all hoses are connected to that and other parts. I use paint markers of various colors to mark hoses before I take them off...well...I did anyhoo.

[A18A]

oh thats when we got it running smooth, when i blocked 2 hoses going to the air cleaner, but it must have been something else adjusted cause before it used to be very putty with the hoses on. i think a basic thing to do now is adjust the throttle stop screw. it was dieseling when idle was higher than 1750rpm, but with it idling around 1000 it doesnt seem to diesel much, maybe a bit of it but barely any. i think tomorrow we will get it running perfect

[A18A]

oo its idling at 250rpm when cold but at least its capable of idling that low

[A18A]

hey i noticed there is NO vacuum on #18 cold - hot, is that right? thats what basicly controls the fast idle unloader and choke puller thingymijig isnt it? and if theres no vacuum, i would have to replace thermovalve-A (that yellow thing 2 hoses comming outta it and its bolted into the intake manifold) and if i do have to replace it, how do i get it iout without breaking it? i broke the spare one too fragile

[A18A]

ok yet again, sorry for flooding this thread with all my shit.. but i came up with a hori idea that could make it warm up alot better..

but first a question, were does the manual choke pulling thingy in the dash go?

and seeing i dont have one..

i could just disconnect the cable on that in its position right? and put a choke sticker on it lol and run a cable from there through a hole already in the firewall and to the throttle linkage and move that lil lever so it stays? cause i just cant get it to idle at all when cold and holding the accelerator down a tiny bit seems to keep it good... just a half assed idea though

[Tailfin]

I forget what else goes on 18, if anything...but if the car is hot, then there should be vacuum to the fast idle unloader definitely... There are 3 thermovalves, I think. A is the one closest to the driver side, B is the one next to it, and C I think is the one near the thermostat.

I had no trouble getting A out to test it...just a wrench on the hex part of it. Stuff like that should have anti-seize lubricant upon installation. All I can think of otherwise is penetrating lubricant.

As for the manual choke, your guess is as good as mine there I've never done that lol...but one thing... If you have to hold the accelerator a little bit to keep it up when it's warming up, that sounds like the fast idle is disengaged. If the car stalls when the throttle is set to have it around 2500 rpm you have a SERIOUS problem. If you're planning on fixing the fast idle (and good luck with that lol), then if you're successful, the car should warm up without the assistance of fine-tuning....unless you just want it to run as best as possible or some silly thing like that.

[A18A]

i hope by rivers side you mean LHD, as for the assistance with warming it up, i cant find no other way at all to fast idle when its cold, only holding the accelerator will stop it from stalling :-/

once the car is warm its really good (idles at 1400rpm), i do wish the idle was under 1000 but beggers cant be choosers, and when its warm there is no putt at all

[A20A1]

I forget what else goes on 18, if anything...but if the car is hot, then there should be vacuum to the fast idle unloader definitely... There are 3 thermovalves, I think. A is the one closest to the driver side, B is the one next to it, and C I think is the one near the thermostat.
I had no trouble getting A out to test it...just a wrench on the hex part of it. Stuff like that should have anti-seize lubricant upon installation. All I can think of otherwise is penetrating lubricant.
As for the manual choke, your guess is as good as mine there I've never done that lol...but one thing... If you have to hold the accelerator a little bit to keep it up when it's warming up, that sounds like the fast idle is disengaged. If the car stalls when the throttle is set to have it around 2500 rpm you have a SERIOUS problem. If you're planning on fixing the fast idle (and good luck with that lol), then if you're successful, the car should warm up without the assistance of fine-tuning....unless you just want it to run as best as possible or some silly thing like that.

I'm pretty sure the thermovalves are different and in different locations for other countries.

[A18A]

whats this? i saw no one answered in my other thread


sometimes very randomly if i put vacuum on it, the car either stalls OR run completly fine, so smooth i couldnt bieleve it, no noisy out the back what so ever, but once turned off it goes back to normal.. ideas? oh it also never had a hose on it when i bought the car, and no marks of 1 thats been on there

and this is the hose i blocked (i think its #8) and made the car run smoother and less putt and black smoke out the exhaust

[A20A1]

Something to bring in fresh filtered air from the air cleaner... a controlled vacuum leak to lean the air/fuel mixture.

[russiankid]

hm...putt putt black smoke happend on my brothers car, it happend to be the slow heater choke not working correctly. It would take like 2 mins to clear it up..then it would warm up fine, but would idle around 1300rpm when it was doing that.

[hotdoghogie]

i dunno if its injected or carrbed but this is for injected...
2000 rpms is way too high for idle... that regular driving rpms for me... i try and keep it under 2000 rpms while cruisin... try checkin the eacv (electronic air control valve) or the fast idle valve that all i can think of... i live with a 25yr experienced honda tech at a dealer... so u can trust what i tell u 100%

[russiankid]

i dunno if its injected or carrbed but this is for injected...
2000 rpms is way too high for idle... that regular driving rpms for me... i try and keep it under 2000 rpms while cruisin... try checkin the eacv (electronic air control valve) or the fast idle valve that all i can think of... i live with a 25yr experienced honda tech at a dealer... so u can trust what i tell u 100%

Well this is in carburetor thread, but he has a carb.

[hotdoghogie]

nvm i seen those pics its carbed... i dunno man... bad carb.... i had this prob on my atv with the floaters sticking... and another carb my floaters misteriously cracked and filled up with gas so the did there wierd thing... get new carbs at a junk yard thats what i would do

[russiankid]

Also overdoes why do you have 2 vacuum lines missing near the engine mount in the pic? And the connector unplugged?

[russiankid]

nvm i seen those pics its carbed... i dunno man... bad carb.... i had this prob on my atv with the floaters sticking... and another carb my floaters misteriously cracked and filled up with gas so the did there wierd thing... get new carbs at a junk yard thats what i would do

Well not always the solution, because my bro pulled a carb off a DX at a junkyard and he rebuilt it, but something was wrong with it. We concluded this because when it was idling and you try to rev it up, it would kind of bog then rev up, more like a slow throttle response.