Hi guys, ive tried searching but not found the same symtoms so sorry if its a repeat ask.. out the other day with plenty of fuel but started to play up on de-acceloration and would not idle so had to keep blipping throttle. I know my low fuel warning light doest work (but then who's does so i know i need to go into the tank of doom and have a fiddle. now she primes strongly for no longer than normal and fires but only runs for 5 seconds or so..... could it be that the pump can only just prime but not enough power to run?? my other thought is the temp sensor but that should stop it from starting altogether if cold me thinks?? if it reads hot would it start a bit then flood?? thanks for any help dom...... devon
When my temp sensor went out, my bike would crank but not start at all, AND the fan came on when I turned the key on, which had NEVER happened before on my bike. You will need to start reading about stuff like the fuel filter, does the bike have the OEM original fuel filter on it? How many miles? Dusty riding? One thing I would encourage you to look at, the Green/red wire which may be the same critical nature on your bike as mine. I chased symptoms of cutting out, blubbering, dying, not idling, etc by thinking it was the fuel filter that I had just changed and I finally found that my Green/red wire was grounding out on a bare spot. This wire is connected to the fuel pump, the fuel pump relay, the fuel injector and the coil! For crazy and unpredictable symptoms, there is no more important wire to examine than the Green/red.
thanks, ill add to my list of checks.. the only filter i know of is the mesh bags in the tank. do they come with another as std? ive only had the bike while so not too familiar with its innerds yet. its only done 1000 miles and if it were dusty here in the SW of england it would make the news as its been raining for 2 years!!! we had summer at 13.15 hrs on july the 9th for two hours though.....oh happy days
ok well ive had a good look around now. had the pump out and replaced cable tie and added an extra one for fun re- soldered the thinnest wire in the world for the low sensor (still no low fuel warning light on but sod it) re-crimped connectors as well to be sure. had a good look round all the connectors etc all of which look good dry and clean. the pump still primes strongly and it starts first time but only for 30 seconds or so then cuts out. Any clues for the next move guys????????????????????
First you mentioned 5 seconds, so I wouldn't have considered it, but now you say 30... Makes me wonder if your fuel tank breather hose is clogged, or some other problem with the cap that's not allowing air into the tank, so you end up starved for fuel. Maybe try running with the cap off to see if it runs normally then?
I havent tried that but i did take the fuel hose of and ran a pipe into a jerrycan. plenty of fuel came out during prime and then on turnover loads of fuel kept on flowing so im fairly sure there is no problem with the pump/filter or breather. checked 3 fuses and all connectors. there was a bit of water in the temp sensor so dried it out and wd40'd it but still the same. also when i turned the ignition on with temp sensor wire off the fan engaged as it should so maybe not tha either (unless its reading warm so too lean a mix but not hot enough for fan?)..... might drop a match in the F#####g tank. why did i sell the honda again????
I would still try the cap off since the fuel line running into a jerry could still allow some air to get into the tank through the fuel line. When it's hooked up, I don't think that can happen. Also, I think there's a thread somewhere about the temperature sensor resistance values. I would definitely check that as well, considering the possibility you mentioned. Although, I think when they usually fail it's either always hot or always cold, not warm. One other thing... The pump itself... I also seem to remember reading about a problem where it would prime okay, but then fail because it gets warm.
Andrew, ill do that for you on my next cigarette... Tempted to drop it in the tank! I can see that it runs long enough to overheat?
Tried that and still the same. Low fuel light works now though I'm just going to order a new temp sensor to eliminate for sure. Do I have to get any potential fault codes ibeated to oblivion or will it run regardless of it I wonder?
Sound like the temp sensor is a good thing to look at, but any chance its spark or timing related? Cam.
I cant quite beleive it but your bang on the money! checked the plug first when it first started cutting out and looked fine and had a good spark. it only had about 15hrs on it but put a new one in and it seems fine ! i need a beer!!! thanks for all your help guys (still going to get a spare temp sensor)
Glad you got it located and it turned out to be something nice and easy. I like to keep these as spares for my TXC: temp sensor, relay, spark plug, fuses and my newest addition to the spares box (from finding out the hard way on two different bikes): starter relay!
I hope when you changed the plug you re-screwed the cap into the wire?? Also you added dielectric grease and taped the cap/wire??? This is a must to prevent water shorting out the spark, either complete short or cause a lighter spark like what you had.
Not yet but I'm still doing the "its working again dance" what do you mean screw it in? It's push fit?
Has anyone come up with a ht Boot that actually keeps the dirt out by sealing against the head properly? Always gets full of crud?
The cap screws on/in the CDI wire. This over time has come undone when accessing the plug. Cut a very small amount off and screw the wire in, grease and wrap tape around the connection.
I would also suggest getting an iridium plug. My bikes all like them, noticeable improvement in my SMS630. Glad you found the issue. Cam.
