Auto-choke Not Working
 

Hey all, new problem developed with my F4i just this last week. I've had it for about a month mostly trouble free (had to adjust the ape cct and that's it). Previously it would start up when cold and the idle would go up to about 3k, as it should, however as of about a week ago it no longer does this. The bike idles under 1,000 rpms when it's cold and it runs pretty weak, takes a bit of extra throttle to be able to take off and even then it's pretty boggy. Once moving it runs like normal and once warmed up it runs amazingly, pulls super hard and doesn't feel like it's lacking power or anything, super smooth and responsive as always. Bike is stock except for an M4 slip on. I pulled the seat off and stuck a paper clip in the little diagnostic wire (not sure what it is technically called) and the bike showed 2 codes, one was "18" which is a faulty cam pulse generator but is supposedly only for if the engine doesn't start or run, maybe an old code? the other was a 9 which is faulty air intake sensor or wiring. I'd pin it on the AIT sensor except that our bikes don't run their automatic choke (and yes, they do have a choke) off of that as far as I know, we have a wax unit that runs off coolant temperature. Could this be caused by a bad (or going bad) FPR? Or is it possible that my wax unit has actually failed (I guess this doesn't happen often)? Help me troubleshoot here! Thanks

I don't know about the fault codes or the sensors. But under 1000 rpm's stationairy is too low. Around 1300/1400 is better.

Have you checked your coolant level?

It idles fine when warmed up. It is only under 1000 when it is cold because the automatic choke is not kicking in.

Coolant level is normal.

The Wax Unit operates the Starter Valves. It's a mechanical operation. I can't imagine the Wax Unit is bad (it's certainly possible), but having something come loose or bound up is more likely. There are several screws on that assembly. I think you're going to have to look closely at the operation to figure out what's wrong.

The wax unit pulls the idle down with coolant temperature. If it was bad, your idle would be high all the time. Check for leaky vacuum lines, FPR, and plugs. Did this happen right after you adjusted the CCT? Cam sensor code with that suggests that your timing may be off?

Have you tried turning you idle up a little by the adjuster screw? Maybe it backed off or someone is having some fun with you...

I haven't had a chance to pull the bike apart yet and check all connections, will do that asap and report back with results. Okay glad to know it's most likely not the wax unit, I'll check my idle screw as well, but I don't think that's an issue as it idles right at 1400 once up to operating temp. Only other issue is that occasionally the bike will hesitate for a few seconds taking off from idle, doesn't happen often, maybe once or twice a week and I ride multiple times every day. This happened a few weeks after the CCT adjustment, and aside from no auto choke and hesitation every now and then the bike runs absolutely flawlessly and super smooth so I don't think the timing would be off. My dad said the exhaust smells rich and I've been kind of thinking that too, but I'm not experience enough around vehicles to recognize all the different exhaust smells yet. So maybe it's the FPR going bad. Thanks for the suggestions everyone!

Definitely sounds like the fpr. How long do you ride at a time? Mine would start up similar, then after about 20-30 minutes of straight riding, it would want to choke out at idle

I'm hoping it's the FPR, kind of spendy but easy fix. Probably is going to foul my plugs if I keep riding it like this. I ride anywhere from 10-30 minutes most of the time just commuting and running errands, once it's warmed up there aren't any problems I've noticed. Haven't had it out on a long ride since this started yet though so I can't say for extended amounts of time. One thing to note is the bike seems to take an extra crank or two to start and sort of sputters to life rather than starting right up like I've noticed most F4is do in youtube videos. Only when it's cold though.

Alright had a chance to pull the bike apart today. FPR tested to be good, no loose hoses or anything either. Other suggestions?

My bike does this too, on start-up it does not have a high idle. The idle is 1200 rpm at start-up and the same after it has warmed up.

Ordered a new FPR for mine to try, have heard it may be due to our hot weather here....but my brothers GSXR runs @ 2500-3k rpm at start up and drops to 1200 after a few second which is what all my other F4i's have done.

Hoping the FPR fixes mine but will be keeping up with this thread in case it doesn't and someone else has found a fix.

bigboi you might be on to something with the hot weather thing. My bike was usually garaged in temps. lower than the outdoor temp, but since I have been storing mine outside under a cover it idles low on cold starts. One time it stalled after startup and the FI light was on. I thought maybe it was bad gas, but the bike runs good once moving and idles at 1300 when warmed up.

Spartan where are you located? Did this just start when the weather got hot and do you store your bike outside in the heat?

Changed out my FPR just now and it made no difference. Idled it up with the adjuster and it just stays idled at where you adjust it. It is easily mid 90's by 10 am here and no lower than 75 so that may be my issue.

Will find out at the end of October when the temp starts to drop I guess lol. As long as it keeps running good I'm happy.

I had similar problem before. But my FI light shows MAP error so I don't know if this applicable to you or not, but might worth a try.

At that time my vacuum hoses that runs to MAP sensor (from the 5 way T throttle bodies) was partially blocked.

You could check all your throttle bodies vacuum hoses whether they are blocked. I just blew some air from my mouth feel the flow.

Good luck :icon_toast:

Hmm this pretty much started when we started getting hot weather too. Weird, maybe it is from that. Thanks for sharing what you guys have found in here, I appreciate it a lot, and thanks for saving me $70 on the FPR! Also important update, today I went out to go riding to try out my new leathers on the CBR, started it, it idled under 1k, continued to idle down, then died and won't start again. I killed the battery trying to start it, primed the fuel pump multiple times, etc, it absolutely will not start. Was raining all night though and sitting outside, doubt that could cause this but what do you guys think? On a side note I took my ninja out riding since it would at least start and it died twice during our ride and took it's sweet time before it would start up again, but it's carbed and has always hated moisture.

A little update, still no luck on the bike. I got it to start by taking the airbox off and running it with just open throttle bodies, go figure. Since then it's ran slightly worse than before it decided to not start, but it runs.

I've narrowed it down to the map sensor (I think) as that made the biggest difference in whether it would start or not. It doesn't throw any codes though, unless I unplug any of the sensors then it throws the corresponding code. The weird thing is the codes don't go away until I wipe them, but when I wipe them then the FI light stays on solid if I short out the diagnostics thing under the seat until I trigger another code. I'm pretty sure it isn't supposed to work like that so maybe I just have a retarded ECU, which could be part of the problem.

I ordered a new map sensor and it didn't help at all either. Next up is to check all of my vacuum lines and after that I'm kind of lost on what to do. I doubt it has to do with horribly misadjusted valves or my bike being out of time, those things don't just happen overnight and when it's warmed up it runs amazingly and I managed to get a 3.5 second 0-60 and under 7 second 0-100mph which shows the bike is performing well despite having issues. Also my spark plugs are coated in carbon and that has to be from a fueling issue.

Also it should be noted that the map sensor I bought is from a honda/acura car. The part number is almost the same and the connector is the same, saw that it would work on another forum. Cost me $17 vs $140 for a new one, and that's a dang good thing considering it didn't help.

Anyone think of anything else to check? I just want to ride my bike lol.

Have you actually checked the vacuum line? Sometimes the problem could be very simple like mine, the hose to MAP sensor was blocked. Good luck

BTW, can you tell me your MAP sensor item code? I'm very interested at $17 MAP sensor :D

No not yet, I think I'm going to just replace them all. I don't have a vacuum gauge unfortunately. Is there a way I can buy all the lines together, or could I just buy the correct size hoses and cut them up myself?

The part number is 079800-3000 for the one I bought (off ebay), the part # for the F4i one (which is the same model as almost all Honda bikes from the same time) is 079800-5780. I couldn't find any used ones for our bikes so I just got the car one, exact same connector the only physical difference is it has two mounting holes vs one. The only other difference is the motorcycle version says "5V-38" the car version says "5V-30," the 5V means 5 volts of course but I'm not sure what the 38/30 stand for. Either way the bike runs just as terribly with either sensor lol.

I just blew air from my mouth :D It was so blocked I was able to tell immediately. Maybe you can try that first before buying any gauge.

I have replaced my hose too. The came in bulk, 1 metre. You'll need 1.6 metre if I remember correctly if you want to change all lines. You need to cut them yourself.

Which hose(s) did you test? all of them? I could feel vacuum from the hose that attaches to the map sensor with my finger but it wasn't much, could definitely be a blockage somewhere. I believe that hose goes into a 5 way splitter that goes to each throttle body.

Thanks for the hose info, do you know the exact dimensions for them? Did you just get them at a hardware store? Thanks!

Honda Motorcycle Parts 2001 CBR600F4 AC THROTTLE BODY (TUBING) Diagram

See the pic in the link above.
Mine was blocked at no. 11.

I disconnected it from MAP sensor, and the 5T joint. Then I blew air from my mouth, and feel the flow with my finger at the end. It should flow freely. It could be any of them in your case. Take them apart one by one, and try to blow. just do it when engine is not running :D

Okay so how many of these vacuum lines should I order? They say 3.5x1000 I'm guessing that means they're 1000cm/1m each so I'd need two of them? the link you gave me says I need a ton of it..

No, you'll need about 1.6 m only. They'll sell in 1m so yeah you need to buy 2 units if you want to replace all. See the part number, they all showing a same part number so you don't need to order separately. Just order 2 units and cut them yourself.

Anyway, blow test your hoses first, you probably only need to replace 1 section instead of the whole lines.

Cool that's what I thought, just wanted to make sure. I might just replace them all lol, then I'll have nice new ones and know they're good. Thanks a bunch!

I'll report back if this fixes it, hopefully it will lol.

Okay new vacuum lines didn't do jack. Neither did new spark plugs, which will probably get fouled pretty quickly if I try and ride the bike like it is.

Back to square one, who knows something about the idle unit? Could it have possibly failed thus giving me no autochoke and leading me on a rabbit trail trying to fix other things?

The bike only throws codes when I mess with the specific sensors, so that plus the fact I've replaced the map and everything that goes to it leads me to believe the issue lies elsewhere.

I'll give you guys my symptoms here again, the bike idles low until it warms up to ~170 degrees, then it runs normal. My old plugs were dry fouled. Turning the idle up when its cold doesn't do much, may 100-200 rpms at best and then the bike will idle crazy high once it's warmed up so the idle isn't misadjusted. The FPR tested fine.

You said your MAP sensor wasn't meant for this bike? Start from there first. Swap with a friend with F4i MAP sensor.

170F is when thermostat open.

Have you ever synced the throttle bodies? Coolant level OK?

I don't think the map sensor is the issue, the stock one and the new one don't make a difference in how it runs. I also don't have any friends with F4is lol.

I'll see what I can find out about the thermostat opening relating to this problem, I figured it was just because the bike was warming up but that might have something to do with it. Coolant level is good though, and the bike never runs excessively hot. It will get up around 200 degrees if I'm moving slow and 225 if I'm sitting in traffic, but once moving it runs around 170-180 depending on how hot it is outside.

Throttle bodies haven't been synced.

Thanks for the help!

Okay another little update, done some more work on the bike, still no luck :(

I adjusted the wax unit, no luck. With the thing pushed all the way in it only idles at about 1200 rpm, from the factory it idles at 3000 rpm and is nowhere near being adjusted all the way in.

Doesn't seem like a failed wax unit, but maybe it's not capable of going in enough? Just doesn't seem likely to me.

Something is making it run like crap when it's cold, up next is a valve adjustment and compression check. If anyone has any more ideas, I'd appreciate it. I'm running out of simple and easy things to check and starting to really dislike this bike

Have you tried adjusting the starter valve? This could be the problem if it's too low you will have rough idle.

https://cbrforum.com/forum/attachmen...1&d=1375167502

I was under the impression that the starter valves are the little things you adjust when syncing the throttle bodies.

Yes thats the one

Well I found the problem.

7 out of my 8 intake valves have less than .005mm clearance (my smallest feeler gauge), the 8th valve has only .005mm clearance. Yep, that'll do it.

Oh boy, this is gonna be fun!

That's a bit extreme?
Are you sure you mesure it right?
BTW my smallest feeler gauge blade is 0.04mm (0.0015")
Maybe you mean 0.005" (0.129mm)?
In that case you are right

I'm pretty sure I measured it right, I'll mess around with it more tomorrow. Maybe it was .05 mm, just checked what I think is the same set of gauges online and they say .05mm, if so then that's a relief, but I'll have to double check. I was definitely reading mm not inches though. Hopefully a smaller set of gauges will fit otherwise I'm going to have to do some shim swapping to get a bass line clearance for new shims, won't be fun to do with how technical getting the cam holder off and back on is. Luckily I measured one exhaust valve (the only easy one to get to) and it was in spec so hopefully the other 7 will be like that.

Screw shim under bucket valves! I love my Ninja the adjustments take me 2 hours tops because it's screw and locknut lol.

How many miles are on your bike? I was under the impression these bikes held their valve clearance for quite awhile unless they are abused.

it's at 23k. I was under the same impression which is why valve clearances were a last resort to check. Fact of the matter is not all bikes hold their clearances as well as others, but I'll bet how the bike has been ridden has something to do with it. Mine has probably had a pretty hard life lol

Intake spec clearance is 0.20mm +/-0.03mm

If yours is 0.05mm means they are waaaay off

Post up the clearances for them when you go to adjust them. What makes you think your bike has had a hard life?

Mine has been running similar on start up and occasionally the FI light would stay on. Yesterday it gave me 2 flashes of the FI light which apparently means the hose to the map sensor is disconnected or there is a problem with my map sensor. I shut the bike off after I saw the code, restarted it and it was fine. I'm gonna have to take a look at the map sensor and see if the hose is disconnected when I have some time.

Alright got all of the intake valves measured, they're between .038 and .061mm, three of them were smaller than .038 but that's the smallest set of feeler gauges I could find so I made an educated guess of .025mm to figure out a shim size. All of my exhaust valves are in spec though... A few are closer to .25mm than .28 but that's still in spec. Tomorrow I'm going to run around to the various shops and see if I can buy some individual shims, then if everything checks out I'll button her back up sync the TBs and she'll be as good as new <3 as much as I've started to hate this bike because of all this ****, I'm excited to have it back on the road lol. I didn't spend big money on it to let it sit and collect dust while I ride my Ninja that needs it's own TLC. Go figure, my honda has given me tons of problems, my kawasaki is mechanically flawless *shrugs*. Hopefully all of the bugs will be worked out after this.

If you saw my bike you'd understand, rough plastics, obviously not maintained as well as it should have been, I've ridden the hell out of it and so did the PO who was a total squid so...

If you're having an FI light with this issue then it is most likely your map sensor. Check all the vacuum hoses on the 5 way splitter that goes into 4 ports on the throttle bodies and into the map sensor, either one has come loose or they've corroded. Or your sensor is shot, you can check the voltage on it, you'll want to doublecheck this but it should read somewhere around 5v. If the sensor is shot just get a honda automotive one, same part used between almost all mid 90s through early 00s honda/acura cars. Same connector and voltage as the F4i, the sensor housing it's has an extra mounting hole and that's it.

Thanks, that's good info. I pulled the plastics and tank the other day and unplugged the sensor and checked the the hose and it all looked fine. Plugged it back in and started and no light. The light came and went but the other day was the only time I got a code. Hopefully mine is fixed without anything else.

Glad to hear you are getting your bike straight.