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Gas Tank Filter?

Discussion in 'Honda Acty' started by ncovi, Jan 22, 2023.

  1. ncovi

    ncovi New Member

    I fighting the infamous and sporadic ACTY power loss gremlin. Will not rev out and lugs then all the sudden it will wake up and run like a beast then next time you start it same thing. I have replaced the carburetor and fuel filter but am still having this issue.

    I saw on another forum that someone mentioned there was a filter inside the gas tank? Is this accurate and how do I get to it? thank you!
     
  2. shogun

    shogun Active Member

    Last edited: Jan 23, 2023 at 1:42 AM
  3. Bert Stevens

    Bert Stevens Active Member

    do you have the carburator with the vaccum line on top? My truck does not have this hose, so I have no "real" knowledge of it full fuction, only what I've read. when I rebuild my carb I got parts from one that had this and so research it. If I remember right, it is part of a rev limiter system. if you have this system, that might be part of the problem. when the line is open the throttle slide does not open fully. This sound to me like a intermittent power valve problem, replacing the carburator would not fix either, if the problem is in the vaccum circuits.
     

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  4. Bert Stevens

    Bert Stevens Active Member

    google , how does a keihin cv carburetor work , I believe their keihin. honda motorcycle use them, I think of my truck has more motorcycle and less pickup. I fell down the rabbit hole this morning, again, looking for that article I read years ago. I grew up on carburetors not EFI. a refresher is always nice. remind me again.
     
  5. ncovi

    ncovi New Member

    Thanks so much for the response, yes it does have that canister on top of it, it was also replaced with the new carburetor but to your point if it's a vacuum issue inside of the vacuum lines somewhere it wouldn't have fixed it. basically I'm $650 carburetor and it does the same thing.

    anyone else had a similar issue and know what valves I can start looking at?
     
  6. Bert Stevens

    Bert Stevens Active Member

    it is not a canister , it is the top cover of the carb, if you pull the hose and plug both hose and nipple, that will defeat the system. you can simply put a piece of plastic bag over the nip and push the hose back on. Do that and see if you power problem goes away. if the control modules, in a box, down stream (or is it up?) are malfuctioning. having a new carb will not matter. same goes for the power valve. a malfuctioning power valve takes away your hill climbing and high speed freeway. your P valve is new with the carb, but is controlled by vaccum. if you have a line leaking, or maybe it is close to falling off a connection. it could cause symptoms like you're describing. that circuit uses the black box, vac reservoir (tank), on top of the engine. tank might have a leak. Don't know if this is your system (routing) but is close. Having warm engine and cool engine changes some things has well, in the way vaccum systems works. is this temp related or driving over a bump related? it might be your ignition coil. might be ignitor on distributor. both can cause intermitent power loss. I'm still betting on loose vaccum lines.
     

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  7. ncovi

    ncovi New Member

    Extremely helfpul and great insight @Bert. Thank you for the note. My ACTY is up at our property in Northern Arizona but I am looking forward to trying this when we return (we just left). I will start with the plastic bag trick. The diagram you sent has something called a Thermo Valve "B". I will say that I had the same issue prior to this.. however when I was swapping out the carb I broke one of the vaccum line outlets on that T style module. I plugged it and combined it using a new T with the line coming in from the check valve "b". The fact that it acted the same prior to this makes me believe it is likely not the problem but I did want to call that out. Perhaps I should order a new thermo valve "b" and replace it to eliminate that possible challenge. Any idea where I could order one of these? Any thoughts if that could be a related issue?
     
  8. ncovi

    ncovi New Member

    Sorry @Bert Stevens I forgot to answer your question, it does not appear to be temp or bump related. It happens whether I take off with temp low or if I warm it all the way up to the mid point first. It starts amazing, goes right into normal choke and idle operation then as soon as it goes under power this happens. After about 10 minutes or 2 miles of lugging it wakes up and runs like a champ (generally until it is shut off then it happens all over again) I saw someones post about a gas tank filter but perhaps those are only in H5, H6, I was thinking this could be a culprit (if it had one) but I cannot seem to find it if it does.
     
  9. Bert Stevens

    Bert Stevens Active Member

    valve B applies full manfold pressure to the distributor advance when cold, for easy starting. when warm it moves over to ported, for variable timing advance. you can get Valve B cheap, 90 civics I think it is, goolge part number. I broke mine too. This is not gas filter symptoms. bad fuel filter is: you run out of gas, slow down, it comes back, you run, you run out, over and over. (just have to drive slow) In my own words, let me see if I have this right . . . you start it, let it warm up, not driving, then starting to drive, have little to no power. after about 10 mins it just stops acting up and runs right. and if you shut it down, restart, it does that again. ( that sound electrical ) . Is it always around 10 minutes? and what type of driving are you doing. easy, normal: stop and go, or hard: up hills or fast acceleration. ?? I will have to think about this awhile. the first thing to pop into my head is sticking float valve. with a vapor barrier/lock, playing a part. Check the fuel return line, from the vapor trap. where did you get your replacment carb? was it rebuild? Trap is part # 1, it allows fuel to return to the tank, so has to NOT put too much pressure on the needle valve (float valve). Just so all know . . I am only trying to add information so that others in the furture may find this help full. I don't know how much a person may or may not know. and I am not talking down to anyone, only trying to help. I do love a mystery. edit, having thought about it. If your needle valve is not seatting properly, allow a little fuel to get by, but staying shut by the high fuel pressure, (locked closed) you could idle and warm up, even drive barely, when you start driving, demanding more fuel, floats drop, needle open, and then starts to work correctly. your good untill you shut down and the vapor lock happen again. I know it doesn't sound like it should happen, carbs are tricky, any thing is possible. possible or probable. at least you can rule it out. When I put my carb back on I left the cover off. so I could see it later, I don't live in a cold area, so I don't need the cover. I would suggest you do the same, at least untill the problem is found. make adjusting and testing easier. Did you try hiting it with a hammer? not joking, a tap in the right place can tell you alot.
     

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  10. ncovi

    ncovi New Member

    @Bert Stevens I absolutely LOVE that you love a mystery because I am stumped. No worries on anything like talking down regarding this, I am a novice when it comes to vaccum and fuel systems and was forced to dig into this myself due to the location of the truck and lack of anyone local that will help. Your thoughts are GREATLY appreciated here. I will get a new Valve B just to cross that off the list but the ACTY was doing the exact same thing prior to me breaking Valve B and prior to me replacing the carb. The carb was from Mac Town Mini Trucks and it was a factory rebuilt carb that I paid around $650 for. We were super happy after installing it and it fired right up and went through the warm up cycle, however the same symptoms presented themselves. To better describe what it is doing. Whether I warm it up or drive cold, as soon as it goes under power it lugs out, meaning I can not get the RPMs over let's say 1,500. I can play with the throttle backing it off and adding throttle to get the engine to fire and the revs to come up. The only fix to this seems to be driving it for about 10 minutes (or 2 miles on my dirt roads) while it is under power, all the sudden it will come to life and drive fine for even 40+ miles on very bumpy roads. Most of the time if it stays warm it will continue to work however there was a couple occasions when I let it stay idling during an errand, hoped back in it and had to start the 2 mile lugging all over again before waking up to full RPM. This is the reason I thought it may be fuel filter related but I totally trust your guidance on that topic. Have you ever heard of a gas tank filter inside of the H4? If so I would like to change it to just cross that one off the list. My plugs were fouling prior and looked dry. I changed plugs and played with the carburator fuel/air mix and idle to what sounded the best. I am at 6,300 feet and now have the dial at about the half way point (it came from the factory at the leanest setting.) None of these adjustments seemed to change anything and I am quite certain it is not a carb issue as (2) carbs have had the exact same symptoms. Sorry for the long note but wanted to get you a little more color on it. I love this truck but have almost given up and sold it several times before finding this forum. appreciate everyones inputs here.
     
  11. Bert Stevens

    Bert Stevens Active Member

    having slept on it, forget all that above about vapor lock, too complex. the simple answer is usually the right one. what your discriping above sounds like weak spark. on older motors (pre electronic) with points, if your dwell was off, you would have weak spark. under load the engine would misfire. you just can't get it to take more thottle. today it is has to be either the coil or the ignitor, coils normal don't get weak, they just go out. so start with the ignitor . you can cheak weak spark simply by pulling one plug and laying on top of the engine in low light, look for what color the spark is. should be blue snap, if yellow orange spark its weak. to keep engine from starting , pull power wire to the valve #11 this controlls fuel to the idle jets. there is alot of information in other posts in this forum, about that valve. a lot of mis information about it on FB. Ebay, don't pay $90 , I got my extra one for $45. it is common for these to go out. they only last 30 years or so. the ignitors usually act up when HOT. but do go from good to bad and back. 30120-PJ7-003
    https://www.rareelectrical.com/i-26...-1982-91-prelude-30120ph7006-30120pj7003.html
    I wouldn't buy from them , just showing that you don't have to pay $$$ and do your own reseach, make sure you have the right part #
    https://www.aliexpress.us/item/3256803583092967.html?gatewayAdapt=glo2usa4itemAdapt&_randl_shipto=US

    amazon has one for $22,

    I would still check the fuel return line, mine was restricted and causing float level to be off. that was befor the rebuild and new needle. I have not had my fuel tank off. the diagrams don't show a filter in there. all tanks have a screen on the intake. It might need cleaning, but I don't see now it could cause your symptoms.

    I have lots of fun in my truck
     

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    Last edited: Jan 25, 2023 at 2:46 PM
  12. ncovi

    ncovi New Member

    Ok, I totally hear you and will certainly give that (and your bag trick) a try. Researching now and again, truly thanks for the help
     

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