Surging problem solved

[saustin]

Hey everybody!

For the past 16 years I've specialized in Goldwing and Valkyrie repair and maintenance.  I want to share something I've come across that's sort of an odd problem, and the fix for it.

Last year a local fellow brought his new-to-him Valk in.  The problem was it surged at idle AND at highway speeds, and his fuel mileage sucked. He had spent $750 at a shop who rebuilt his carbs and tossed a few other parts at it .   I've learned not to trust what I've been told some OTHER mechanic has done, but upon inspection found the carbs were beautiful and perfect.  The shop had done a fine job, they just wouldn't work on his bike anymore because they couldn't fix it.  A multi-day search of all the 'Wing and Valk forums yielded nothing I hadn't already checked.

To make a long story even longer, I stumbled upon a site for cars in the UK with the same issues.  They are using an engine coolant temperature sensor identical to the ones Honda uses in the 'Wings and Vlaks, same part number and all.  This is NOT to be confused with the temperature sending unit nor the thermo switch.  It's a whole different item.

It's located on the right intake manifold and is tied in with the brain, and reads the coolant temps, sending signals to the brain which in turn enrich or lean your fuel mixture.  Bench testing them with the boiling water method won't help you, because the brain reads in milliseconds and the response time of your sensor might be ½ second.  There's no way to tell.

I replaced the part, and everything was great.  Now the proof; 2 weeks later I get a '96 GL1500 with the SAME PROBLEM!  Replaced the sensor, and it's all good.

Now, perhaps I'm not the first “Wing and Valk guy to find this, but darned if I could find anything on the boards.  If I've found it in 2 bikes, I suspect there are more of these aging beauties out there being miss-diagnosed and never straightened out.

The part is listed in the on-line parts fiches as follows:
GL1500, found under “Water Pipe”, #22, Sensor, coolant temp part #36151-MT8-003
Valk:  found under “Waterpipe/thermostat”, part #8  same part number as above.
Retail: $43.51

Just a sidebar; U.S. cars don't use this part on ANYTHING, so you're stuck buying from Honda.  In Europe, they're common and ½ the money.

I hope this helps someone.  I never post anymore, but thought this might be worth the time.

Scott Austin

[olddog1946]

thanks for taking the time to post this.

[Skinhead]

It's located on the right intake manifold and is tied in with the brain, and reads the coolant temps, sending signals to the brain which in turn enrich or lean your fuel mixture.


How does this affect a carburated valkyrie?  I could see a fuel injected wing.

[weeder]

It's located on the right intake manifold and is tied in with the brain, and reads the coolant temps, sending signals to the brain which in turn enrich or lean your fuel mixture.


How does this affect a carburated valkyrie?  I could see a fuel injected wing.

ditto

[gordonv]

Isn't it the IS model only that has the 2 sensors in the engine?

You mentioned fuel mileage sucks, any idea what that was? US/UK gals or L/Km?

[hubcapsc]

Isn't it the IS model only that has the 2 sensors in the engine?

You mentioned fuel mileage sucks, any idea what that was? US/UK gals or L/Km?

I just looked up all that stuff he was describing on the 97 Tourer fiche... its all there...

-Mike

[KG]

wouldn't it be the same as the ECT mod? If you were to switch it back and forth rapidly wouldn't it change the timing back and forth creating a surge?

[saustin]

On the carbureted models it opens and closes another part of the fuel/air circuit.  And yes, adjusts the timing as well.  I don't know if this has anything to do with the ect mod because I haven't read about that.  I'm guessing ECT stands for engine coolant temp, in which case it would be related.  All I know is that, for $43 bucks, this works without mickey-mousing anything.

The surge is caused by the engine trying it's best to match the fuel mixture setting with the engine temp, but lagging behind in it's job.  Fuel mileage suffers because it's dumping more fuel into the engine than is requires, just like running your choke partially on.

[KG]

ECT mod
http://www.valkyrieriders.com/shoptalk/ect-mod.htm

Want better mid-range performance and better mileage? Up to now, the choice has been to use a timing wheel that uses a fixed advance of either 4 or 6 degrees. Two drawbacks of mechanically advancing your timing is that some have difficult cold starting problems, and the loss of power at the high RPM's. An alternative?  Utilize the function of your Engine Coolant Temperature sensor or ECT sensor circuits already in your ECM and you can avoid both of the potential problems mentioned above.

When your bike is cold, your ECT sensor (a thermistor) causes your ECM to advance your timing about 10 degrees. Contrary to popular belief, that advance does not quit above idle. It stays on above 3k RPM and then backs off as you approach 3.5k rpm. Have you ever noticed that your bike seems stronger when it is cold? By inserting a resistor or preferably a potentiometer in series with the ECT sensor, you can have that advance all the time, warm or cold. You don't have cold starting problems, because the total advance is limited to 10 degrees (vs adding an additional forced 4-6 degrees). And you don't lose any high RPM power because the advance quits automatically above 3.5k RPM.

---------------------------------------------

So as I see it if the engine coolant sensor is changing resistance rapidly it could cause the ECM to affect the engine timing causing a surge

[Bigwolf]

SAustin,

I can understand how a faulty temp sensor would cause a Valkyrie to surge up to about 3500 rpm but it will not cause it to surge above 3500 RPM.  Such a surge would be the effect of shifting timing.  The Valk ICM does not adjust the timing for engine coolant temp when RPMs are above 3500.   There are no wires connected to any of the carbs on my Valk.  That means no electronic adjustments to fuel mixture. 

Maybe you are talking about an F6C.  The F6C looks like a valk.....it has the same engine as a valk..sort of....However, the F6C is very different than a Valk.  There is an electrical switch mounted on the carb bank in an F6C.

[saustin]

Thanks, KG.  Well researched, well put.

I stopped posting things back in 2004.  I had my own Goldwing shop, had folks bring their 'Wings from everywhere between Maine and Florida to me, had carbs shipped from all over the world for repairs.  Was the district director for the GWRRA classic Goldwing group, and regularly wrote technical columns.  Gave lectures on classic 'Wings and repair issues.  I was a prolific poster on the tech columns.  Had articles published in magazines.  I NEVER posted or printed anything without researching it to the nines, and then checking it out myself.  It's not that I hate to be wrong, but there ain't anything better than being right!  LOL!

I had a customer bring me a bike with a problem, and per indications, I did a leak down test, determining there was a problem in an exhaust valve that required a more extensive look.  After explaining it all to him, he made a post on a world wide site questioning my call (even though the procedure ultimately would have saved him money), and I was bombasted by folks that didn't even know what a leak down test was.  It put me in the unfortunate position to try to explain the procedure, to essentially defend myself from attacks by people who, even though unversed in the fine points of mechanics, implied I was a fraud and a charlatan.  Not really good for my business OR my reputation. Gotta tell you, it kind of ticked me off, and I pretty much quit posting.

Your analysis and cure are spot on, and for us "motor heads" who want that last horsey, you couldn't be more right.  Perhaps because I've dealt with the casual rider, I've sometime oversimplified my explanations.  Hey, some guys won't change their own oil, and that's ok.  I won't do anything that involves a board or a nail.  A man's got to know his limitations.

That being said, I'm just hoping my original post will help some guys who are stumped by their local shops.  I would think the average Honda dealer mechanic might see a few 'Wings each year.  Not their  fault they don't know everything about one obscure bike.

Sorry for rambling, but it kind of feels good to do this again.  Thanks again, KG.  Ride safe, ride often.

Scott

[saustin]

Howdy Bigwolf!  You're correct, there are NO wires to your carb.  I've got all my notes in the garage, but it's 12:15, and I ain't going out in the dark to get them.  LOL!!!!  There is a circuit that the ECT sensor activates, and I'll try to get to the notes tomorrow.  Being retired, I can't promise you anything, but I'll get to it.

Hey, sorry if I came off as a know it all jerk before, but sometimes a bit of tongue in cheek humor doesn't come off well in type.  Respect.

Scott

[Jim500]

If you are using a IS ecm is the ect mod effected the same?

[Bighead]

Scott I thank you for posting this as when I read a cure for a problem I file it away in my own memory bank. I might not remember every detail but can search it here and find it once again

[IamGCW]

Good catch.  While likely rare now, in the years to come as the bikes age this may be a bigger issues.  Thanks for posting this.

Gil

[Big Tom 10628]

Just wanted to say thanks SAUSTIN for this information. I know that this topic is several years old but It was linked from the Steve Saunders Goldwing forum.. My '98 GW has a surging problem.

[6adan]

I had this same problem on my 95 GL 1500 Goldwing several years ago and saw a post on Steve Sanders forum. Was that you that posted on there? I changed it out and it worked great. If your bike is doing the surge thing change it.    Dannie

[Jersey]

Saustin - Thanks for a great post!  Really appreciate the details and explanation!  Sorry to hear of the incident, but hope you'll post more in the future.  I'll keep this one in the back of my mind should the ol girl start to surge.

Jersey

[6adan]

Jersey, if you don't mind where are you in southern Maryland? I used to live there in the 60. I lived in Ridge and at Point Lookout before it became a state park. Dannie

[ridingron]

https://www.partsfish.com/oemparts/a/hon/506c2f6bf870023420a31b42/water-pipe-thermostat

[Bret SD]

I have/had? a problem with my 02 standard surging at idle.. sometimes..

When I ride on the freeway here in San Diego it's often at 4000 rpm to keep up with traffic, then I get off and the idle, which was at 900-1000 rpm surges up to 1700-1800 and stays (until it cools off), sometimes the high idle stays for awhile even after the bike cools down.
It was driving me crazy, then I read this thread and ordered the sensor. So today I installed it and rode at 4000-4200 rpm for several miles, when I got off the freeway the idle was around 1100 rpm.

Hopefully the idle will stabilize and my gas mileage will improve. I'm getting avg 26 mpg riding around the usual tracks, yesterday my girl and I took an 80+ mile ride into the mountains at avg 3000-3300 rpm and I got 31 mpg. The bike never idled up when riding at lower rpm, the surge only seems to happen after the 80-85 mph freeway runs.

[MAGA]

My 1999 i/s starting idle is 900-1000 rpm, but as bike warms up to normal running temperature,  the idle increases to 1200-1300 when I come to a stop. Any ideas to fix? Should I replace the coolant part that was reccommended?

[Bret SD]

I replaced the sensor and found no joy, the idle is still up after running down the road, like up to 1700 rpm, it's driving me crazy.
Another crazy piece of the puzzle is when (twice now) I've adjusted the idle down manually it just happens again. You would think with the mechanical idle adjustment there would be a finite point where you can't lower it anymore.
It bums me out cuz other than that the bike runs flawlessly with lots of power, no hesitation, flat spots or any other problem. Honestly it's so aggravating I didn't ride it yesterday at all.

My 82 GW is a much more consistent runner than the 02 Valk, should be the other way around I would think.

[MAGA]

Thank you bretshim. Sounds like you have a similar problem. I'm worried about overheating when I am waiting for a long stoplight to turn green (I live in the desert), the cooling fan kicks on sooner than normal. And, when shifting the bike from neutral to 1st gear, the transmission really kicks abruptly into gear, I think because of the higher surging rpm.
Any recommendations? It drives me nuts, too.

[Bret SD]

Holy crap!
I just looked at your location, my sister lives on Cornville Rd. and I have family in Oak Creek and Rimrock. I usually go there at least twice a year but haven't been since my dad passed in early April. I'm relocating within San Diego in the next couple months so won't be there till spring some time I think. Though lately I've been dreaming of hopping on the Valk and just going for it.. pipe dream right now though...

Back to the surge at idle
Mine doesn't do it all the time, sometimse I'll go for a week with no problem, then it comes back. It seems to happen when I run hard with traffic at 80 mph or more. If I cruise at 3-3500 rpm it idles normally when stopped (usually) but there is no consistent pattern.
It may have to do with the #38 pilot jets I installed when rebuilding the carbs, when I did that I found 2 down tubes with the back edges folded and leaking vacuum, also the #5 cylinder had a completely clogged slow jet. It was cutting slightly in windy conditions at higher rpm due to the vacuum leak.
Since then I've tightened clamps, bolts etc looking for a vac leak problem, my motor is de-smogged and I run a pingel fuel valve. I got the vacuum caps from redeye for the six ports, so I don't think it's a vacuum leak problem.

When taking loose the radiator to install the new sensor I found the fins are folded over in many spots, so I'll go through with an angle pic and straighten them out, the bike seems to run cool enough as it is but I want to fix the problem fins anyway. One of the PO's was a hack.

So I'm still thinking it's a heat and fuel/timing controller type issue. I'm no expert with these things but have a decently solid background in automotive repair work.

I'll keep digging and experimenting, we can't be the only ones with this problem. Do you know if your bike has been molested in the past like mine?

[Ricky-D]

I have/had? a problem with my 02 standard surging at idle.. sometimes..

When I ride on the freeway here in San Diego it's often at 4000 rpm to keep up with traffic, then I get off and the idle, which was at 900-1000 rpm surges up to 1700-1800 and stays (until it cools off), sometimes the high idle stays for awhile even after the bike cools down.
It was driving me crazy, then I read this thread and ordered the sensor. So today I installed it and rode at 4000-4200 rpm for several miles, when I got off the freeway the idle was around 1100 rpm.

Hopefully the idle will stabilize and my gas mileage will improve. I'm getting avg 26 mpg riding around the usual tracks, yesterday my girl and I took an 80+ mile ride into the mountains at avg 3000-3300 rpm and I got 31 mpg. The bike never idled up when riding at lower rpm, the surge only seems to happen after the 80-85 mph freeway runs.

It would probably be better to start a new thread seeing you're in a thread that indicates the problem has been "SOLVED".

Regardless of that, I think your problem is definitely carburetor related. I don't understand why you modified the jets and needles (the valkyrie naturally runs rich in stock condition) but the first thing I'd suggest to do is to get the carburetors back to stock condition.

***

[Bret SD]

Thanks Ricky,
 
I'll start a new thread at some point, right now I have no time to do follow up on it or put any quality time into the work..

I used 38s to not deal with clogging, big mistake.. the needles are stock with one washer. The PO had doubled the washers, I don't know if he messed with the timing. Will find out at some point..

[Chrisj CMA]

My 1999 i/s starting idle is 900-1000 rpm, but as bike warms up to normal running temperature,  the idle increases to 1200-1300 when I come to a stop. Any ideas to fix? Should I replace the coolant part that was reccommended?

Adjust the idle to 900-1000 WHEN WARM. A valk running right will barely stay running without holding the throttle or using the choke when first started cold