Does my carburetor need rebuilding? (’84 Accord)

[Reginald]

So my car, a 1984 Honda Accord, has been having the following problems lately:

• Hesitates/stumbles on acceleration
• Misfires under load
• Will not stay running when cold/humid, stalls within seconds

I’ve ruled out problems with weak spark or the ignition system. I’ve replaced the ignition coil, spark plugs (OK condition), spark plug wires, distributor (was leaking oil internally), distributor cap, air filter, and there are no vacuum leaks. Battery and alternator were tested and determined to be OK. The ignition timing is likely retarded (incompetent mechanic’s fault) since the vehicle has had poor acceleration/lack of power ever since the distributor was replaced (month ago). RPM at idle is usually 800, although sometimes it will randomly be higher when stopped at a red light (bouncing between 1100 and 1500), at which time I have to be very careful when I accelerate and it fixes itself a few seconds later and stabilizes. It also idles much higher (2500 RPM) once in a blue moon when I start the car, but settles back down to normal after driving for a couple of minutes. Like I said, no vacuum leaks.

I no longer drive the car at night at all, since it always does one of the following: 1) Dies within seconds of starting, then becomes very difficult to start again, 2) Runs OK until you get about two blocks away, then dies and repeats #1 over and over again – have to get a tow, or 3) Runs OK until you stop the car at a location within a short distance of where you started it (i.e. gas station), then when you start it again, either #1 or #2 will occur. This also happens if it is very humid or raining. However it will NOT happen at all if it’s a warm, sunny dry day. I can drive it during the day for hours in 100F and heavy traffic and it won’t stall.
^ Note that the car did not have this problem with stalling until about three months ago. I was told by a mechanic that the cold start enrichment circuit in the carburetor may be malfunctioning and causing misfires. This page about my Keihin carburetor has been informative as well.

I don’t think the problem is a bad fuel pump. If it was that, it would be stalling all the time regardless of weather or time of day. I’m going to replace the fuel filters (yes, there are two on my car) later this week when they come in the mail, just as a precaution. I’ve called multiple shops specializing in carburetors in my area, and I found one that will rebuild it for $250 (or just $130 if I take the carb out myself). Other shops wanted to charge me double that for the very same services. I don’t know what else it could be at this point. I’ve checked the throttle shafts, choke plate and butterfly valves – they are clean. The accelerator pump squirts out a decent stream of fuel into one of the bores when I press down on it with my finger. The fuel level in both fuel bowls are right where they should be. On another note, I found the previous owner tells me that the carburetor was rebuilt in 2010 and I have the receipt as proof. That was about 40,000 miles ago (and if you’re curious, the car has only 121,000 miles on it). Does it really need another rebuilding already? Or is it something else?

Topic

[Reginald]

[quote=”college man” post=167796]see if this helps.

https://www.youtube.com/watch?v=KgGUcSvUgMg%5B/quote%5D

Seen it before. My carburetor is different anyway.

[Reginald]

[Reginald]

So I took my car back to the carb shop this morning, under warranty. Turns out the problem is not the carburetor anymore – it’s weak spark. The mechanic tells me something is causing resistance in the distributor (which is barely two months old, by the way). He showed me using a test light that he hooked up to one of the spark plugs – the light was dim and inconsistent, indicating weak spark. I told him I tuned everything up not long ago. He said to have someone look at the distributor again. Could retarded ignition timing cause this, or what?

[college man]

see if this helps. I know your car runs but it shows spark diagnostic.

http://www.ericthecarguy.com/faq/solving-automotive-no-start-problems

[Reginald]

[quote=”college man” post=168163]see if this helps. I know your car runs but it shows spark diagnostic.

http://www.ericthecarguy.com/faq/solving-automotive-no-start-problems%5B/quote%5D

I’m looking into it. I hope it’s not an internal problem in the distributor, ’cause that thing is new and it means those incompetent mechanics charged me for a crappy job.

A look inside the distributor again. I played with the rotor a bit, the metal part on it is a little dirty.

https://youtu.be/NHVdSIoR4k8

I also looked at the connections on the ignition coil. The negative connection was considerably loose, so I tightened it. The hex nut won’t turn in all the way – I can tighten it to an extent, but if I turn it past a certain point, it becomes loose again, basically stuck in the same spot. I left it on there in a tight position for now. The positive terminal, on the other hand, is as tight as can be.

[Mike]

Sounds like the terminal stud is stripped. You can try placing a thick-ish washer under the nut as a spacer so the nut tightens up on the remaining good portion of the threads.

[Author]

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