Carburettor problems/questions

[denhonda]

My '82 1.6 auto has carb trouble & the Keihin 22/28 carb has been removed & partially stripped for inspection. 2 glasses of red wine came in very helpful when stripping it as before I just looked at the thing contemplating leaving it to another day.

Anyway it was straightforward enough & I have a reasonable idea with whats up with it... I think. The gasket between the 2 chambers had disintegrated, however I'm not sure that would cause any real running problems... The float chamber has a little gunge/corrosion at the very bottom & could very likely contribute to fouled up jets - which is essentially what the running faults indicate to (the mixture was running rich too)... car was difficult to start, cutting out at idle & when increasing throttle, but ran fine on fast throttle. It ultimately broke down & had to be recovered by tow truck.

To cure I'm going to clean up the float chamber as best I can & gonna get the jets blown thru. I've got a gasket set on order too. Then its a case of putting it back together & taking it from there.

Another option would be to replace the carb. Obviously Webers have been tried & tested so thats an option. However I've got a spare 32/34 carb off a '85 1.8 Accord auto which is in excellent condition. It looks virtually identical & would fit but is this a good idea & what would it been for fuel consumption/performance & all that?

In the manuals it makes mention of Venturi diameters. I dunno what these are TBH but for the 1.6 they are for the primary 0.866 in (22mm) & secondary 1.102 in (28mm)... then for the 1.8 they are...1.26 in (32mm) & ... 1.34 in (34mm). Does this mean anything to anyone?

There are no carb shops in my locale as far as I'm aware, I trawled thru the internet & phone directory & made a few calls without success.

So your help would be much appreciated!

[2ndGenGuy]

I guess the question is do you want to tinker around with reliability, or do you want everything to work as is? I'd say for reliability purposes, rebuild your factory carb (since it sounds like you're already there) and go with it.

The carb swap to the 85 would be interesting. I don't know if it's properly jetted to your motor or not. If jets aren't changeable, I have a feeling it wouldn't run right on your 1.6.

The Weber does always work. They can be tweaked and tuned to run on any engine and are pretty reliable. A new one can be spendy though ($300+ US), and parts for them hard to find, and spendy as well. I paid $100US for a jet kit, just so I could play with my jetting to see whats up. Plus you have to buy adapters, and do a little bit of fabrication.

Just my $0.02

[denhonda]

Well you know what? I've decided right here & now that I think I'm gonna chuck the '85 carb in & see what it does! The car is immobile atm & that really pisses me off !

I am gonna rebuild the old carb though as (like you say) I've got the kit coming for it & it'll be there for me if this change doesn't work out.

Whats the worst that can happen ?

[Ichiban]

To answer your venturi size question, it is basically the ultimate size of each barrel. Larger means more flow, but potentially less vacuum. You are installing a larger carburettor. Does the bottom flange bolt pattern line up? I seem to remember them being different.

[denhonda]

To answer your venturi size question, it is basically the ultimate size of each barrel. Larger means more flow, but potentially less vacuum. You are installing a larger carburettor. Does the bottom flange bolt pattern line up? I seem to remember them being different.

More flow & maybe less vacuum... How would this affect the overall perfomance of the engine? I'm asking (not questioning) as I'm sure there will be a difference, be it good or bad! Overall I'm not up to speed on these matters.

The carb lines up 100% with the bolt pattern.

I'm no further forward with anything having been away at my Dads this weekend, so we'll see what the coming week brings.

[Ichiban]

Typically a primary bore on a multi-barrel carb is smaller, which lends better throttle response and torque characteristics. Going to a larger overall carb can help overall breathing at high rpm due to increased flow, but may hurt bottom end/torque. You may have to rejet the carb as well as change the geometry of the accelerator pump linkage to get it to run right. I'd still throw it on and see how it runs. You might be surprised.

[denhonda]

Typically a primary bore on a multi-barrel carb is smaller, which lends better throttle response and torque characteristics. Going to a larger overall carb can help overall breathing at high rpm due to increased flow, but may hurt bottom end/torque. You may have to rejet the carb as well as change the geometry of the accelerator pump linkage to get it to run right. I'd still throw it on and see how it runs. You might be surprised.

Ahh, I see... you know your stuff! Its throttle & torque I'd be keen to see improved as (lets face it) this car ain't no high-reving V-Tec! If the bigger carb has a noticeable adverse affect on performance, it'll be changed for the rebuilt correct one.

Sound advice, will report on how I get on this week!

[denhonda]

Well I fitted the other carb today & guess what ?

The car is running exactly as it did before. Exactly.

So this brings me to the possible conclusion that theres something else up. But I dunno what.

To recap, the car is difficult to start, it now idles okay though (which tbh, immediately before I took the old carb off, it started & idled ok too), it runs okay on fast idle, but it doesn't like being revved showing signs of either a misfire or fuel starvation & then it dies. It'll restart again with persuasion. It starts readily with a squirt of easy-start.

This problem seemed to come about following the adjustments by a local garage to get the car through the emmisions. Before that the car had been running & driving 100% It was then garaged for the winter. It was taken out for its first run of the year to Honda 4 months later (30 mile drive) for a timing belt & tune up as the car was cutting out when coming to a stop & when I got the car back, it was barely driveable breaking down 1 mile later.

Various ignition parts have been renewed in recent months & have been tried & tested. The plugs, cap & rotor arm are all ok & the leads were renewed too. The only thing thats not been changed recently is the fuel filter which I'm going to attend to hopefully tomorrow.

Would a dodgy fuel filter fail so suddenly?

This is getting really boring now

[2ndGenGuy]

Maybe the advance in your distributor isn't working properly. You have another parts car don't you? Can you try the distributor off of that car?

[Ichiban]

Check the timing maybe?

[denhonda]

Check the timing maybe?

Thank-you all for your continued help with this!

The cars running was far worse when it came back from Honda (T-belt) but I put this down to them trying to adjust the carb settings without success. So this makes sense. The distributor has not been messed with & I don't have a compatable spare, but will bear this in mind.

There were running problems before this obviously, but the car was still driveable. I'm guessing the disintegrated carb gasket would contribute to this & the high emmisions.

The fuel filter is getting changed anyway so the timing will now be my next port of call if it doesn't make any difference. This should be looked at by Honda then if they've f**ked it up. Not going to be easy when the car is stranded at home.

Grrr.

[Ichiban]

You can always start the car, get it to idle, and mess with the ignition timing by ear. If it rattles, back off, if it lopes and sputters and slows down, advance slightly. Or you could borrow a timing light and simply check it properly. If you do the ear method, it would be a good idea to first scribe alignment marks on the distributer base and head so you can put it back to what it was if it goes for shit.

I think you're on the right track by fixing all the vacuum leaks and verifying the carburettor systems. My 83 packed it in one day on me, I thought it was out of gas, turns out it was a bad coil. Go figure.

Also, on the EL 1602, I've seen 2 timing belts installed out 1 tooth on the cam pulley. This is because the marks appear to line up when looking down at the cam gear, but when you actually cram your head in the bay and view them in line, they don't match up. this causes both ignition and valve timing to be retarded about 8-10 degrees. Seems to be a common error. I'd check it out.