1987 Honda CRX HF 1.5 HELP

[s-harris@juno.com]

Another question: My '87 CRX HF is the only carbureted car I own. When it runs good, it is AWESOME!! I love this car. Unfortunately, though, it will just start running like crap intermittently. When this happens, I run Seafoam in the gas, spray carb cleaner into the carb, and generally nurse it along until I get my idle speed to stabilize again until the next time the issue decides to flare back up. While I am capable of doing this, I'm getting kinda sick of it. Since I can get it to recover, I am assuming I have dirt/contamination issues in the carb that need occasional cleaning.

My quesion is, with a clean carb, how many miles should you typically get before dirt/contamination is an issue? It seems I can't get more than a few thousand miles between cleanings. I have been wondering if I should:

1) Tear the carb down and clean it internally
2) Replace the carb with a rebuilt unit

So, the question to anyone that knows the answer, is if I exercise options 1 or 2 will I get 20,000 - 30,000 miles of trouble free operation (with respect to dirt issues in the carb)? I don't know carburetors, so maybe they're just prone to dirt issues. Since the one on my car is capable of functioning well (at times) if may be just as good as a potential replacement. In other words, after Seafoam/carb cleaner, if my current carb is truly now clean, should I see issues again a few thousand miles later? Is this typical for a carburetor or should I suspect that mine is a piece of crap and in need of repair/replacement? I don't want to tear down or replace my carb if I don't gain the potential of an extended period of trouble free operation (with respect to carb issues). If, on the other hand, it can keep me from the stalls, misses, and general annoyance that happen all too frequently in my opinion then maybe options 1 or 2 are great options.

FYI, the carb on my '87 CRX HF was a rebuilt unit that I installed about 45,000 miles ago. I would hope the guy that rebuilt it had it in like new condition when I purchased it. I got it from a carburetor place online (send in your old carb and he replaces it with a rebuilt unit). My CRX does sit at times (maybe some varnishing could occur) but I am hoping the Seafoam breaks this back down. If not, are there any other great additives that should clean out/break down gunk/dirt/varish in a carb? I have been using Seafoam as it was the best stuff on the market in the late 80's. Is there now something else better that won't eat all of my diaphragms/seals (remember, this is a vintage car).

Also, when I spray my carb down, I just spray everything I can see until it seems cleaner. Other than the vent hole referenced above, are they any other areas in the carb I should pay special attention to? Any specific spots that are prone to cause issues? Does anyone have a photo that shows all vents/jets and what they do on the '87 HF model? Since I typically experience idle issues, I'm wondering which specific areas contribute to that function/failure mode.

[theholycow]

With dirt/contamination being the issue, my first thought wasn't to tear down or replace the carb...my first thought was to consider where it's coming from.

• Leak at the air filter? Make sure everything fits tightly.
• Vacuum leak? Find and fix.
• Fuel filter collapsed? Replace.
• Contaminated fuel? Remove fuel, clean tank, flush lines, replace filter, etc.
• I also wonder if fuel is evaporating from the bowl(s) and leaving varnish.

I don't think you should be experiencing that short service interval. I think once it's clean it should probably stay running ok for a long time.

I too have a carburetor. I am not a fan of the concept. Mine is reasonably well behaved but no carburetor can handle environmental changes the way fuel injection does. My idle speed varies by ambient temperature, but not merely proportionally; instead the choke might be more on or more off, resulting in higher or lower idle almost randomly. I've observed it long enough to know its patterns, so I know in the hottest part of the summer it idles low, in spring and fall it idles high, in moderately cold winter it starts rough and idles high, then in the coldest part of winter it idles low or even stalls and I must open the throttle some to keep it alive.

Anyway, rambling aside, mine does not require or benefit from period cleaning like yours. I acquired the car at 35,000 miles with unknown history, drove it 3000 miles then parked it for 5 years, and in the past 3 years I've put on 55,000 miles. At first I had to give it a lot of exterior cleaning to free up the choke linkages but they've stayed free since then. Also once or twice I've run fuel system cleaner in the fuel, probably the way you used Seafoam, but observed no results.

[trollbait]

Some might consider it contamination, but are you running E10 in the car now? It could be the culprit, but it might be helping you out in the long run. ethanol can cause the same problems as biodiesel in older vehicles. Both are stronger solvents than gas or diesel, and older vehicles can have a build up of gunk in the tank.

I suspect the ethanol is cleaning the gunk out of the tank, but some of it ends up clogging your carb in time. You can do as THC suggested for contaminated fuel and clean out the tank, or you can let it just progress as is, possibly help it along with Seafoam or carb cleaner in each tank. The tank will eventually get cleaned out. If you take the last route, keep a new fuel filter in the car with the required tools to change it.

You can mix up your own Seafoam: Homebrew Sea Foam (SeaFoam) Motor Treatment Recipe
Klean Strip paint thinner(not the low odor one) is pretty close to Gumout fuel injector cleaner. Acetone is also effective fuel system cleaner, but needs care not to get it on the paint.

[s-harris@juno.com]

Thanks for the well-thought replies.

For the moment, I am running Seafoam in the gas and I increased my idle speed. What was happening was that the current idle speed (was 1000 rpm with nothing else loading the system) was enough to keep the car running during the daytime, but if the headlights were turned on, my idle would drop and the car would tend to stall at every stop (the idle would oscillate between 700-900 RPM at times and then typically plunge into a stall). I was having to shadow the gas pedal with my foot while I was braking to prevent constantly restarting my engine at every stop.

While I had things opened up to elevate my idle speed I sprayed the vent hole several times to help ensure it was as clean as I could get it. Each time I shot the vent the idle would surge up for a few seconds and then calm back down.

Anyway, with the elevated idle, it has ceased stalling. Now that it can actually run at idle, I suspect the idle system is passing the fuel/seafoam mixture and getting the scrubbing it seems to desperately need. From my carburetor research, it appears the jets in play during throttle and idle are different. Since my car seemed alright as long as I didn't let it idle I suspected the jets that were clogged were the idle jets.

I may try to mix the homebrew seafoam and keep up the clean. Yes, most of the winter I run 10% ethanol blend as I live in Michigan and it's easier to buy it in my gas than it is to buy HEET to add.

Background on what I've done:

The car sat for many years before being brough back into service. Due to this I wondered about the state of the fuel system components.

I have:

1) Replaced the little fuel filter between the fuel pump and the carb
2) Replaced the fuel filter next to the gas tank at the rear
3) Drained the gas tank and ran everything through a coffee filter to see if there was any debris in the tank (rust chunks or anything). I didn't find anything there.
4) Looked through all of the vacuum lines and they all seem to be connected properly and sealing well
5) Tightened down all the bolts/screws in the carb to try to ensure no air was coming in from unintended sources
6) Cleaned the carb repeatedly both with carb cleaner (externally) and fuel additives (internally)

I did buy a new fuel pump just thinking maybe it was causing issues, but I never installed it as I later decided it probably was a work/not work component and since the car was running I figured why replace a working component.

I may very well be working crud through the fuel system, but with a fuel filter near the tank and before the carb, how can junk really make it all the way to the carb? The filters probably have under 5,000 miles on them so I would hope they still have some life left in them. Is there stuff small enough to get through the filters but still troublesome enough to cause my issues?

I change the air filter regularly. The current filter probably has under 10,000 miles on it. I'm running a paper filter. The rubber seals on the bottom and the top of the air filter housing are in place and I tighten the top down enough that it should seal well. I have considered switching over to a K&N to lower any airflow restrictions, but somebody told me when they were running their K&N that contaminant levels in their oil were up significantly so I shyed away from that idea.

It seems like you guys have given me everything to look for. Now I just need to back track through everything and double/triple check all potential sources.

On a separate note.........my car (at least for the moment) seems to be running pretty well. It will get up to 70ish fairly well, but seems to top out at 70-80. If I'm going up a slight grade, sometimes it will slow down to 67-68 with my foot to the floor. A) This is an older car with 147,000 miles on it. B) This is the HF model, so the horsepower is not an impressive feature of this engine. Both of those things being true, has anyone experimented with opening up the airflow on the intake, the exhaust, or both and noticed if it improved the top end? I'd like to avoid being the guy on the highway that can't maintain at least 70mph because the engine is maxed out. Thoughts or experiences?

Thanks again for all of your feedback!!

[s-harris@juno.com]

Update.....my fuel lines were leaking. I replaced all of the fuel lines under the hood. They were original and had little cracks in them around where they coupled. Air must have been creeping in and wreaking havoc on my idle speed. After swapping the lines:

1) My idle (when it wants to idle) is very stable
2) My off-the-line launch power is much improved. My dash used to rattle a lot and I had to do more nursing of the clutch to get a launcy
3) It runs smooth as silk on the highway. It used to feel like it was missing here and there, but now it doesn't miss at all.

You would think things would be great, but alas, that would just be too easy. My idle is still diving to stall at stop lights once the engine is warmed up. I sprayed the carb out once again and am hoping it will run better on the way home tonight.

Here is a new one, too. I was driving in and the engine just died (never did this before). It used to stall out at stops, but wouldn't die while my foot was on the throttle. Anyway, I was driving along at 50 mph and it just died. I pulled over, threw it in nuetral, and went to restart it. It started and then died immediately (if it was on for 1 second I would be surprised). I did this twice more with the same results. I got out, opened the gas cap (there was no vacuum hiss like sometimes there is), put the gas cap back on, and tried to start it again. It started fine and drove in to work normally. It still wanted to stall at stops, but no sudden dying like what it did.

Anyway, as I said, I sprayed carb cleaner into the carb and left it to sit all day. Tonight, hopefully it will run great on the way home. When I get home I'm going to inspect the flexible fuel lines in the rear. It may be a good idea to replace all of the rubber fuel lines in the back (engine bay done already as mentioned above). I'm just afraid to try an unbolt the tank as I don't want things breaking off. This car is old and has enough underbody rust that I try not to disturb things more than critically necessary as sometimes things break off as opposed to unbolting when I mess with them.

Anyway, the project continues, but the under hood fuel lines are definitely a step in the right direction

[trollbait]

Is there stuff small enough to get through the filters but still troublesome enough to cause my issues?

It could something, like a varnish or gum, that is dissolved in the fuel. When shut down, fuel residue in the carb evaporates, leaving the substance behind. Knew a guy who bought a car that sat for ten years. It started fine, but the old gas left such deposits on the valves that ended up bending a couple of push rods.

It's a good practice not use gas that sat for a few years. Even with the old gas gone, there could be a gunk build up in the tank. The ethanol and/or change in fuel or additive formula can be dissolving the the gunk, and then depositing it in the carb.

Or it is the fuel hoses. I think cars were made for the possibility of E10 back then. Assuming the lines were still in good shape. With deterioration, ethanol compatiable or not, the fuel can be dissolving something out of the hoses themselves. I'd replace them.

[theholycow]

Originally Posted by trollbait

I think cars were made for the possibility of E10 back then.

Yup. 1980 Buick owner's manual:

[trollbait]

Another possibility on how old fuel lines could be the culprit. Fine particles could be coming off the lines into the fuel. Small enough to get through the filter, but could be depositing in the carb due to heat.

[s-harris@juno.com]

I think it's all finally coming together.

First, the sudden stall issue. I've gotta tell the story. After work my car started and drove fine (except wanting to stall out at stops, but as explained above - different failure mode). I drove the car 47 miles and maybe 25ft before pulling into my parking place it did the sudden dying thing again and absolutely would not restart. Or more specifically, it would seem to start when cranking, but die the second the key was released. The short version is the ignition switch died. The cool thing is that when it happened in the morning I was able to restart and get to work. The car then got me home and died in such a way that I coasted to where I park. I had full access to my tools, no tow truck had to be called, wasn't stranded anywhere. Of all the possible ways to experience a mechanical failure, I can't think of a more "best case scenario". Driving a car as old as mine, maintenance/repair is just to be expected. The way it happened, though, just makes me feel like God is looking out for me

Okay, now to the stalling out at stops issue. I had a new fuel pump sitting in my garage. I had purchased it, but a buddy told me fuel pumps either work or they don't - no real in between. Based on that, and since I'm apparently lazy, I figured why do work with no potential benefit to be had. Anyway, while trying to figure out why my car would seem to start while cranking and then immediately die, I wondered if somehow pumping the gas got things primed enough to start but then I didn't have enough continuous fuel pressure to keep things running. I decided to change the fuel pump just because I had one sitting there. Anyway, after changing the fuel pump nothing improved on the starting issue because my ignition switch wouldn't let the car run. Last night, though, I took the ignition switch apart and cleaned it up (RockAuto is shipping me a new one, but I want my car working during the interim). That got my car running again. Here is the cool part.........it's running like new. This morning on the way in, no stalls at stop signs. It is running perfect at idle. None of the former symptoms showed up on the way in. Granted, I've only driven it once since last messing with things, but I drove 47 miles and nothing. I could never go that long before without experiencing symptoms. I am very cautiously OPTIMISTIC (the "very" belongs with the optimistic part of that statement). Maybe I should rephrase it as.....I am cautiously very optimistic. I may have an awesomely running CRX to get me through the winter.

I love my CRX. It was really bumming me out that it kind of seemed to be going in the crapper and knowing that I can't just go out and grab another Gen 1 at my convenience if mine dies. When this thing goes, it sadly won't be replaceable. I'm really trying to keep this thing alive for as long as possible because I know whatever I replace it with just WON'T BE AN AWESOME CRX I have other cars, but my CRX is awesome in ways that no other car I've found can measure up to. It was like the perfect storm of vehicle design. Anyway, I'm THRILLED that mine seems to be working great again

Thanks to everyone that has taken the time to suffer through this with me. Since you have your own CRXs, you understand why I'm not willing to let mine go down without a fight.

[s-harris@juno.com]

Since we're talking CRX's, does anyone know where to find specific data on the 1987 CRX HF carburetor? I have the two barrel with electronic idle control. My car SEEMS to be running fine so I'm not in crisis here. Since I was going through things, though, I started checking vacuum on several places on my carburetor that looked like they probably had diaphragms in them. I found a few spots where the vacuum was held fine and a few where it wouldn't hold a vacuum at all. Knowing where I SHOULD be able to hold vacuum and where it isn't even designed to hold it will help me better understand if I have more to fix or not. Who knows, maybe I can get from the high 30's back into the high 40's if I get things right. My car used to get 45 in the summer and 37-38 in the winter. Lately it seems to just stay between 36 and 39 mpg. It had some fuel issues, though, as you know, so I haven't had time or exposure to see what it is doing since the last rounds of fixes.