I am helping my friend put a new engine in his car, its in, and its a stock replacement, 3 berrel carb, everything on there is what is on there back in 84 (just off another car)

So I assumed it would run the same, without any heavy problems, but now for some reasion, when the engine starts up, it starts at 1k rpms, and slowly gains to about 4k rpms (Which is normally when we shut the car off because of noise, but it would probably continue its climb until something broke)

And I have to manually choke the carb just to get it to stay within the 1k area, the engine is just hauling ass, and theres no real way to stop it from going to the upwards of 4k+ rpms
We've checked the carb (I'm the 'carb' guy) and theres a guy there that knows engines (but nothing about carbs), the thing is, I'm a Chevy guy (first honda job ever), 4 berrels and such, and the engine guy is a ford guy (which makes conversations fun) but neither of us know what could be the problem as I have never worked on a Inline 4 before, and he has never worked with so many vaccum lines.

So please, any help would be greatly appreciated, as this car has to take my friend from willows, CA to Carson City, Nevada in aweek

I just came into the whole 'group' of mechanics only 3 days ago, as I have been moving from my old place to my new place (makes sense eh ) so I don't know what all they did minus the work they have done with me there.

ANd another thing, just off the top of my head, the engine is pumping mad fumes from its exhaust, nomatter how I tune the carb, I'm thinking it could be one of many things, but I'm reluctant to admit it may be the Carb (As I am the one who 'fixed' it) but is there anything on there that isn't normally on a carb that I should know about? (I'm used to working on Q-Jets and Edelbrocks mostly)

Thank you in advance, and you have a good day
-Karma

 

Sounds like either a vacuum leak or the throttle isn't closing. Last carb I had was a '72 Datsun & I've never done Hondas or Chevys, so I can just make vague generalizations.

Is the throttle closing all the way? How about the secondary? Is the primary-to-secondary linkage goofed up so the secondary is open a little at idle? If it's closed, I'd keep looking for vacuum leaks.

What's the third barrel? Only 3-bbl I've ever heard of was on my dad's CVCC Civic, & the 3rd was really tiny. Is that what yours is?

 

Thank you for the reply,
The 3rd berrel is insanely small, when I first looked at the carb from a distants I said it was a 2 berrel (I was originally told it was a one berrel) and then later I realised that the tiny little hole is the 3rd berrel.

The Vaccum lines are all set up (by the owner of the car, as I was gone that day, they all look connected), minus the ones for the air cleaner sensors and such (I can't remember the actual name for it right now, just woke up) whould those cause a problem at all? cause I would hate to disconnect and then reconnnect those lines after every adjustment to the carb.

And this may sound like an stupid question, I'm far from a mechanic, just a guy that likes old cars with Carbs and such, but this 3b carb is much differant then the ones I'm used to, but I take it that the linkage and such acts in the same way as it would on any other carb right?

-Karma

 

my old 85 Accord LX had all sorts of carb problems, including where the engine would rev up to almost 5k before i shut it off. a carb rebuild did the trick and some of the vacuum lines were shot too. double check and then redouble check the vacuum lines. even one that looks good may be cracked or not seated right, causing erratic operation (but you already knew that). The vacuum lines are what kept the car good with the emission standards of 1984/85 and one bad line can throw the whole thing off.

 

The vacuum lines that go to the air cleaner - you said they weren't connected. At least plug them, there's your vacuum leak. I think they operate the damper that mixes hot & cold air coming into the air cleaner.

I think(??) the carb is mostly normal compared to old-school carbs. But I didn't really work on dad's car that much. Besides, his was '77 and maybe wasn't exactly the same as yours.

The 3rd barrel is supposed to run richer than the primary. In that stratified-charge CVCC engine, the rich mixture from the 3rd barrel ends up near the spark plug, so it can ignite. The rest of the charge can be leaner, because it doesn't have to be ignited directly by the spark.

 

My dad's 87 sentra had the same problem recently. Like everyone else said, the problem was several vacuum lines that were so old they literally split at the ends. The solution- 67 cent/per foot new vacuum lines.