Hi, i recently bought an fj, rode it home, but it was rough starting off/at low rpms and was very hard to start. ran great at higher rpms though. now it wont fire at all. i replaced the spark plugs since i was going to do that anyhow, but that didnt change anything. seems like an ignition problem to me. the bike alerady has replacement dyna coils in it from the last guy. does this sound like a coil problem, cdi box, or entirely different realm? thanks
Welcome FNG, have you done anything else to trouble soot the problem? Did you pull the plugs to see if you are getting spark? Are the plugs wet? There are many simple things to check to eliminate possible causes. The rough starting could be from sitting too long and the idle jets clogging up. Very common problem. What year is you FJ? Early years are gravity feed and later years have a fuel pump. That means other things to check that depends on the year. What can we call you besides bikeguy91.
As FJmonkey indicated, more information please :good2:.
"now it won't fire at all" , did you check the ignition fuse and make sure your kill switch is in the run position. Simple things first... Where are you located in the world ?
George
can call me greg. its an 85 fj1100. its getting spark and the plugs aren't wet. all i've really checked is the plugs since it did fire before. once in a while, on a full battery, it will fire for a couple seconds then quit, but only on occasion. this site seemed really helpful for other repairs so i thought i would see if anyone could help before pouring money into it, since i dont have a lot to spend on it. (the $500 electronic ignition systems are out of the question)
located in Massachusetts. yes the kill switch is off and fuses are good.
Thanks
Quote from: bikeguy91 on October 24, 2013, 10:51:37 AM
it will fire for a couple seconds then quit, but only on occasion.
Greg,
When I bought my first FJ it started well on choke, but was rough starting off and at low RPM. Ran quite well WOT, but I didn't realize how much more was waiting for me. It sounds to me like you have a more advanced case of clogged carbs than I had.
You should do the most thorough carb cleaning you can and then do it again to make sure they're spotless and totally unplugged, especially the pilot jets and circuits. You might also make sure there's no crap entering the fuel system from the tank.
You're in for a big treat... keep pressing through the resistance.
Frank
Are the carbs getting fuel? A pinched (improperly routed) fuel line or if the vacuum line to the petcock is cracked it can prevent fuel from flowing.
the lines are routed as pictured on the bike(factory) and the carbs were supposedly "just cleaned" by the guy i bought it from. guess i should check that out for myself.
also the vacuum line is a little frayed at the top. i dont think it would prevent suction, but worth a try. much better than the problems i was thinking i had.
thanks all
If you are going to pull the carbs, check what size pilot jets you have. After putting #40 in, the bike runs better at idle.
If *all your plugs* are dry, it's fuel related. It would be strange to have all your carbs gum up at once, although many stranger things have happened...
I would look at the the petcock not opening....here's how to check: on your '85 you have 3 settings on your petcock...on...off...and P for prime. Normally your petcock setting should be in the on position.
To test if the problem is with the petcock, turn the petcock lever to the P position and try to start the bike.
See if your plugs are wet. The P position opens the petcock in absence of a vacuum signal so the petcock is open all the time.
Don't leave the petcock in the P position, you can flood your engine, flood your garage floor, etc.
It might be time to invest in a new petcock from RPM.
The new petcock I got from Randy has two positions, PRI and RUN. Run doubles as the OFF position when there is no vacuum.
Ok good to know, thx Mark :good:
In this event, turn the petcock to PRI. and see if this gets gas to your plugs.
You are getting good advice here. You are on the FJ learning curve. First as indicated just focus on getting fuel to the carbs. Assume nothing. Your plugs shouldn't be dry. While you are looking at things make sure your choke is functioning at the carbs. Make sure the previous owner did not put a fuel filter in the line. Also when cranking your engine crack open the throttle.
There is more to check but when doing this via the forum without knowledgeable hands and eyeball's at the bike we have to cover the basic things first.
Sounds like the previous owner was having problems with it and didn't get it sorted out. Its a new to you bike and you will probably have to inspect things closely as you go. I would recommend you get a service manual when you can.
Have patience it is just a machine and it can be sorted out. My advice is do not tear into the carbs until you understand how they work and how to service them. If you get to that point then go to the files section and read all the carb files, probably more than once. :good2:
George
A few ideas:
As you changed plugs....double check to see if wires are on in right order? Probably are but you never know....
Pull number 1 wire and check to see if you have spark. As there are two coils I think you might also want to check 3 but I cannot remember exactly.
"Prime" it with a bit of ether or gas...does it fire or run then?
Jeff
thanks guys! im going to take the petcock off and clean it, but i know it was getting gas very recently since the bike drove home a week ago. im thinking clean out the lines and petcock, then carbs and give it a try.
Quote from: bikeguy91 on October 24, 2013, 04:29:30 PM
thanks guys! im going to take the petcock off and clean it, but i know it was getting gas very recently since the bike drove home a week ago. im thinking clean out the lines and petcock, then carbs and give it a try.
If you are going to go that far then give your petcock the "suck test" before you remove it. Disconnect the vacuum line at the intake manifold, disconnect one of the fuel lines and have a catch pan/bottle under it to catch the fuel that should come out. Make sure there are no sources of ignition. Suck on the vacuum line. On a good petcock you will be able to suck some air out of the line and then feel it stop, as if the line was pinched off. Fuel will be flowing at this point. Or you will need to keep sucking to keep the fuel flowing due to an air leak in the hose or petcock diaphragm. If enough air is leaking you will have intermittent flow, really bad flow or no fuel flow. This problem plagued me for a few months before I found it on my 86'. If you have to keep sucking then you need a new petcock, even if fuel is flowing, it will only get worse and strand you someplace far from home. I got a 60 mile ride in a flatbed tow truck back to my house instead of meeting up with some friends for a ride one Sunday. :dash2: :dash2: :dash2:
My money is on blocked choke circuits. The PO cleaned the carbs and probably missed cleaning the small holes in the float bodies. This is a very commonly overlooked place to clean. Spray carb cleaner down the hole in the float body and see if it exits through the hole at the bottom of the bowl. Sometimes compressed air is enough to clear this out but occasionally it may need clearing with a fine piece of wire. Use a piece of soft wire, i.e. copper or aluminium, so you don't enlarge the dimensions of this orifice. :i_am_so_happy: Pete.
While you are working on the carbs put the battery on a charger. Starting problems are tough on the battery. A weak battery will cause starting and running problems too.
OK, If you get into checking the ignition, another way is to remove the left side ignition pick-up cover (4 screws). Put a timing light on no. 1 plug wire and have someone crank it briefly and check timing. Should get a light at TDC mark. Got fire at TDC then good. Got no fire, bad. Air, fuel, fire...
But do the fuel checks first, follow FJmoney's advice. Then if it were me I would do the timing light check, if OK then read about rebuilding/cleaning the carbs.
If you have to remove the carbs then ask questions first. There is a hard way and an easier way.
George
Quote from: movenon on October 24, 2013, 07:24:56 PM
OK, If you get into checking the ignition, another way is to remove the left side ignition pick-up cover (4 screws). Put a timing light on no. 1 plug wire and have someone crank it briefly and check timing. Should get a light at TDC mark. Got fire at TDC then good. Got no fire, bad. Air, fuel, fire...
George
This ended up being my trouble a year ago...The spark was being produced on all four cylinders, but at the wrong time (180 degrees out) and no start. Putting a light on the timing puck will clear this up quickly and you can check ignition off your list. With dry plugs, it does seem fuel related, but this is a pretty simple test...if you happen to own a timing light. :yes:
Cap'n Ron. . .
Quote from: Capn Ron on October 24, 2013, 07:46:52 PM
Quote from: movenon on October 24, 2013, 07:24:56 PM
OK, If you get into checking the ignition, another way is to remove the left side ignition pick-up cover (4 screws). Put a timing light on no. 1 plug wire and have someone crank it briefly and check timing. Should get a light at TDC mark. Got fire at TDC then good. Got no fire, bad. Air, fuel, fire...
George
This ended up being my trouble a year ago...The spark was being produced on all four cylinders, but at the wrong time (180 degrees out) and no start. Putting a light on the timing puck will clear this up quickly and you can check ignition off your list. With dry plugs, it does seem fuel related, but this is a pretty simple test...if you happen to own a timing light. :yes:
Cap'n Ron. . .
Last spring when I advanced the timing plate 4 degrees I used a timing light just to check things out. I was hoping to see and measure the advance but that must be controlled in the CDI unit. No matter the RPM the light fires at TDC I couldn't see any advance. But it will tell you if you have fire (in your case yes, but 180 out :lol:)... That was a good find.
Not much of a use for timing lights with the new car I guess. You see used timing lights at yard sales and used tool dealers all the time for cheap.
George
EVERY seller will claim that "the carbs were just cleaned" but that hardly ever the case. You have a fuel delivery problem.
The ignition fires each coil once per crank revolution. You will see a spark every 180 degrees of crank rotation bouncing between the 2 coils. If you see a spark 180 degrees off, then you're on the wrong coil. The #1 and #4 cylinders will spark at TDC, the 2/3 coil fires 180 degrees out.
Quote from: FJ_Hooligan on October 25, 2013, 02:10:06 PM
If you see a spark 180 degrees off, then you're on the wrong coil.
Yeah, that's definitely the case if someone was taking a timing light tap from either the #2 or #3 cylinders, they would see the timing at 180 degrees out. You've got a bad mechanic. :biggrin:
If you're taking the timing light tap from the #1 cylinder and you see the timing at 180 degrees out, you've got a bad ignitor.
Cap'n Ron. . .
the part of the petcock that moves out to allow fuel with the vacuum on, and in to stop flow when off was stuck. I have the petcock working now. hopefully that fixes the problem. I replaced the fuel lines and crankcase vent while i was there as well.
Quote from: bikeguy91 on November 01, 2013, 10:01:30 PM
the part of the petcock that moves out to allow fuel with the vacuum on, and in to stop flow when off was stuck. I have the petcock working now. hopefully that fixes the problem. I replaced the fuel lines and crankcase vent while i was there as well.
Glad you found the problem. You might safety wire it. PLEASE read or scan through the threads below. I think the petcock can be replaced with a better designed unit if it comes to that. "FJmonkey" can give you some advice on that.
http://www.fjowners.com/index.php?topic=3265.0 (http://www.fjowners.com/index.php?topic=3265.0)
http://www.fjowners.com/index.php?topic=3251.0 (http://www.fjowners.com/index.php?topic=3251.0)
George
Failed the "Suck Test" eh? Glad you found it, fustrating as hell till you find it and fix it.
thanks for the links movenon. I will definitely be safety wiring mine, even though its not loose. better safe than sorry