engine won't run unless choke is closed

[Vanilla Sky]

ok, i have an 87 DX here that i have to get running soon, very soon.

when the car starts up, it starts fine. it will rev up to about 1000RPM and die, sometimes it'll chug a bit at 200-300RPM. if i hold the choke plate closed, the car runs, and will idle as high as 1800RPM, and allow me to drive it around the block.

the car has been sitting for quite some time. honestly, the gas i pulled out of it was purchased when gas was around $1.50 a gallon. it's that old.

the carb is obviously getting fuel, so i at first ruled out the fuel filters. right now, they're my most likely suspects.

if i'm remembering things correctly, an idle going up when the choke is closed is the sign of an engine running lean. with that said, do you guys think i should replace the fuel filters first, and see where that gets me, or should i be looking at other items.

a partial vacuum removal has been done, but it wasn't performed cleanly. this is making things harder for me to sort out. i may very well end up performing a full stage one following mike's how-to if you guys can't help and the fuel filters do nothing for me.

TIA
Derick

[2oodoor]

Derrick,you have dual id too on 3geez. omg, you got me. lollololol
you know you gotta get rid of that gas, ya may get by with just underhood filter, and check for electriitronic corrosion on all primary from battery, on up to carb and dist. then secondary under dist cap, dude is this a pop quiz, or you just are not a carb guy, Ive seen you in some deep tech threads and you are asking a no brainer. wasss up. no disrespect.yep primary means all relays and fuse connections and under the seat, grounds, and leave the gas cap off till you get it running.

[Vanilla Sky]

i can do fine if the carb is stock. since this one has had a vac removal done, i'm somewhat stumped. i'm not sure if it's something i should be checking into or if it simply sound slike the fuel filters.

all things being equal, i'd rather be working on an LXi. i can handle fuel injection all day long and not get tired of it. these keihin carbs kill me. if this were my car, i'd seriously consider a weber. the owner of the car originally wanted to go DCOE, but he payed me with them. i hope to see him with DCOEs sometime in the future.

[2oodoor]

yea ok I was wondering.... my bad...yep I have been working with carbs for years and have built many that most would not touch but this Honda one, well I just cant beleive all the controls they engineered for it to run perfectly smooth at all times , well it does not hold up to enviornmental and temperature variances so it is a failure in my perspective. EFI if the best , but noting wrong with carbs if you try to keep the basic circuits in mind. You should search forum , A20A1 has put a lot of effort into getting useable information in there ,plus a lot of feedback threads. It may be something simple, most likely, the three things I would look at is make sure the ABC is using A I think, make sure fuel cuttoff solenoid is working properly, and check thermowax valve operations, and , all the other things we have mentioned here already, old gas can really make a mess inside carb. top hat off and do a gentle clean out trying not to disturb too much and clean needle and seat with mild efforts in gas,no cleaners unless your gonna buy a kit, set float, etc.... I have converted to weber, but I still think I need to reconnect dist vacuum thermowax valves to make the warm up cycle better when its freezing outside. I am still trying to figure out the vacuum choke pulloff on the weber, I think there must be a plug over it.I guess it has one ?? time to find out what the diaphragm is by the elec choke with no hoses goiing to it.

[Tailfin]

Do you mean closing the choke completely makes it run? If so, that sounds weird. If it's closed completely, it should snuff the engine for the most part. On that alone, it sounds like you've got air coming in from somewhere else. Did you check for a nasty vacuum leak?

The chokes are a pain in the arse on these things (like the rest isn't lol), and are, in my opinion, the most important part to get perfect. I have personally been going through hell and back trying to perfect an 88 so you don't have to hold the accursed pedal for a bit in order to warm it up cold. So far, what I found is that even if the engine was warm, closing the choke a bit raised the rpm, and the choke heater always opened the plate too far, so it would stall after warmed up. So I tightened the choke return spring (which I put on manually), but then it was too tight and wouldn't open when trying to start the car. What I ended up doing was engineering the choke to be in just one position (just a smigin more open than the stock cold start distance), by bending the tab that seats on the carb and removing the heater. Hopefully you'll get it before then.

If you hold the pedal down and let it warm up, does it still die?

[Vanilla Sky]

the car was warmed up when we were making it run with the choke closed.

and no, the choke wasn't all the way closed. it was closed about 75%.

[A20A1]

Ground wires, power to pump...

Float level?


vacuum leak?
Try removing the brake booter line and plugging it.
Also check for
leaky PCV
leaky Manifold gaskets
leaky Carb Gaskets
leaky throttle shaft

plugged vent holes on top of carb

power to solenoid at back of carb
make sure the solenoid works.

[Vanilla Sky]

the whole car seems like a big vacuum leak. i may be having fun just doing a proper conversion on it. i believe PCV was bypassed. i'll check the gaskets for sure.

i do know that the float bowl level is dead on. there is nothing leaking out anywhere.

so you think i should pass on the fuel filters?

i think i'm going to check the ground wire. it sounds dumb enough to be the problem, and it's something i'd certainly overlook (and have before).

[Tailfin]

As far as I can tell, that's all the choke is supposed to open when it first starts up. Is your choke return spring alright? It should be completely closed when cold.

[Vanilla Sky]

i know it should be when it's cold, but i'm talking about when the engine has been running for a good 45 minutes.

[Tailfin]

Got voltage to the choke heater? The bimetallic spring in there is what opens the choke further when the car warms up. It's that circular cover doodad that's on the passenger side of the carb by the choke linkage. Make sure that is installed, with the index marks lined up and that the spring isn't installed so it doesn't hit the choke lever.

[Vanilla Sky]

the choke is open when the car's warm. it won't run when it's warm and the choke is open.

[2oodoor]

yea Tailfin his problem is oppsite of what your trying to tell him I think...
Vanilla this sounds like a good sized vacuum leak to me, I dont know if you have solved this yet , thread is a few weeks old. I wil say that converting to weber is the best thing, I am loving mine. I am driving my car daily now and getting super good mpg, its close to 30 , it has been cold every morning this week so that old problem I used to have ,, bye bye... lol'
I have one more day to go on 5 gallons of gas , on work commute and so far I have 134 miles on that 5 gallons, and still have a little before its on E yet.
I have DC header, smitthys metal streight thru muffler with 2 inch all the way out the back, this Accord sounds like no other honda Ive ever heard, it is really quiet, yet has steight thru exhaust, it has a nice tone though.
My new problem is that the fast idle screw does not even reach the fast idle cam but barely, the spring is totally compressed, and I also as soon as I find time I need to see if I can adjust the vacuum pulloff for when it first starts before the choke heater moves the choke. The vacuum pulloff is supposed to open it slightley too. Heck I may not even have one, like I said there is something there that looks like a pulloff but has a brass plug in the end of it.
This weber came off a mazda b2000 truck. You can find webers in the JY, if you look hard. They came on a lot of 4cyl and 6 cyl Ford Pinto, Capri, Mustang II, Vega, Monza, and dont forget to look under any japanese 80's vintage cars, a lot were converted because nobody liked working on the asian carbs. You just have to make a linkage setup and maybe a jet change ,depending on how close you can get your tune.

[Vanilla Sky]

it's not my car. it just has to run long enough on the interstate for me to deliver the car. i'm trying to spend a minimal amount of money on the car. if it were mine, i'd order a DCOE manifold and put my DCOEs on.

[Tailfin]

Ah well in that case, it sounds like my problem lol. Try disconnecting the choke heater then. That's what I did to mine. I have removed all vacuum except for distributor advances, one to the choke opener, the accelerator pump thingy (that important one on the back lol), and the cruise control/AC idle boost stuff. I'm certain I have no distinct vacuum leak; I did the intake manifold gasket as well, and I've been having that problem as well. I think it's just a pos lol. But from what I can tell, when I closed the choke opener, the mixture actually richens from the air going through faster, moreso than choking it (haha...). Basically Bournoulli is winning over here.

The only thing I can even think of for a reason is the fact that the engine has 180,000 miles on it, and perhaps wear has increased clearances, blowby, and therefore decreased compression, thereby decreasing the strength of the vacuum created when the piston sucks the air down...but good lord man...and that sounds a bit far-fetched to be the reason. Maybe the valve clearance...hmm...

But anyway, bottom line is when I disconnected my choke heater, the last thing it did was not let enough air in. It seemed to run fine. Given the circumstances and the budget, I'd say try that.

[Tailfin]

Ah...well like I said, I essentially have the exact same problem here...and I just discovered that mixture cutoff solenoid going into the back of the carb is completely useless, and needs replacing. Might wanna check that.