FI light indicator at 75-90, loses power, gas mileage help

[troykahack]

The bad fuel has to be long gone. I have put on more than 1200 miles since I accidentally put 87 in the tank. That was just the first time it set the code????

I think I will replace thermostat and first confirm left or right knock sensor with a extension wire swap. Great ideas. But Thermostat will be replaced. I will update later. So much to pay attention too when reading the gauges at the time of no failure and failure. I never much gave too much attention to thermostat as generally it is pretty warm here and running at 3 bars in normal for me.

Must change thermostat as it really appears to be bad as it stuck open. Regardless of what is going on, it needs to be replaced. So I will start there and then see what happens and use a wiring jumper if I still set a code on Knock sensors. I noticed in manual the knock sensors were under exhaust pipes.

Again, great ideas and thoughts,

Thank you,
Rory

 

[Redfish]

For a bit of light reading...

https://www.st-owners.com/forums/showthread.php?132408-FI-Code-26

 

[troykahack]

Redfish,

Thank you.... I read your entire thread. I guess I am looking for a ECM/ECU for a 2003 without ABS .... does the ABS matter for the ECM? I might just try resetting the module but from everything I have read that you have done, it sounds like your problem was just as mine presents itself. The mileage you see drop off is the same as mine. The feeling with the wind guest is the same.....

If anyone has a spare ECM/ECU they would like to sale, please let me know. I looked on Ebay and none seem to be available. Will continue to look for one or maybe an admin can give this a bump.

Rory

 

[troykahack]

Also,

Is there a quick way to replace the thermostat or must I go through that involved process to change it. In Florida, it seldom gets cold enough to make a big deal about it I don't believe. I think it is much better to be stuck open than closed.

Rory

 

[v8-7]

The thermo can be accessed by taking off the radiator . Of course you do need to strip off most of the plastic to get to it though.

 

[Redfish]

I would not spring for an ECU just yet, there are too many variables.

I am pretty sure there is some information on this forum about the best way to change the T-Stat. If you are going by the procedure in the Service Manual, don't. There is no need to remove the throttle body assembly. Remove the Tupperware, remove the radiator, then the T-Stat housing is easily accessible from straight in front. I put that off and put that off and then found it was all done in a very short time. Not nearly as bad as you think going in. Worrying about it is worse than doing it.

I stress to you that the ECU is doing the equivalent of "choking" the fuel mixture in an effort to get the engine to the correct operating temperature. It does affect your fuel mileage.

Spend some fun time with you bike and learn about Tupperware Removal. It will pay off for you later.

 

[st1300r]

Thermostat is easy pull the radiator. Replace the o-ring at the same time. It should run rich if the t-stat is stuck open and the bike can't warm up. AFAIK the 03 is the same with the diag connector

 

[st1300r]

Some more light reading LINK

 

[troykahack]

I just upgraded to site supporter....

st1300r...

I read your thread, thank you again, and this forum. I am really on hold until I get a ECM which I have been unable to locate. I have tired Ebay without any luck. Some guy advises he has them but he just has one for the Goldwing and my investigation indicates it will not work. So, here again, I am looking for a ECM to fit 2003-2007 . What is unique about the above link, his problem also started after putting in a tank of low octane gas like I did. I have ran STP injection cleaner through mine twice and now have over 1500-2000 miles run through the bike at about 31-35 mpg. SeaFoam didn't fix his issues either. I would like to pull the plastic off as few times as possible.

Thermostat, I will order one and did find some good thread to replace without removal of throttle body. However, it is not warm here again in Florida, Typically I don't ride when it is cold out, we have thin blood here. LOL the night I rode with the two bars was like 49 air temp. I froze to death. Yesterday, I started the bike in garage and it went right to 3 bars before in finished its idle warm up. The time I saw the two bars was actually the coldest I have run the bike in. How sensitive is the ECM to 2 bars versus the 3-4 bars? Does anyone really feel this is the cause of my fault code 26? Everything I read, in almost every case on the forum groups, seems to indicate almost every time with the same symtoms I have to be a ECM. Loss of fuel mileage 30-35 range, light sets, bike feels like it is riding into a bit of wind, just increase throttle and it seems to overcome the wind (imagined). I am going to replace the Thermostat just for good cause and age. I need to pull the plastic a bit to learn how. But does anyone with experence with this problem like I have, really believe the Thermostat is my problem. I am not convinced. But it should be replaced so I don't foul plugs at low temp.

So, looking for ECM for 2003-2007. I posted on Parts Wanted section. If anyone comes about a ECM, please let me know.

Thanks again to everyone, such an awesome site. How do you become a contributor. I contributed once before when I need advice, would like to do so again.



Rory

 

[Blrfl]

I would like to pull the plastic off as few times as possible.

The more times you do it, the easier it gets, and it doesn't have any ill effects. This is a great opportunity to get to know your bike.

How sensitive is the ECM to 2 bars versus the 3-4 bars? Does anyone really feel this is the cause of my fault code 26?

Three bars is normal operating temperature, which your bike will reach and maintain easily if it isn't moving. You shouldn't be seeing four, especially with an open thermostat. I ride in 100+-degree temperatures in the summer and can't make it hit four without disconnecting the fans.

When the engine is below operating temperature, the ECM will enrich the mixture until it is. This makes more heat to bring the engine up to temperature and reduces fuel economy because it's burning more fuel. The rich mixture is also not one that gives the best engine performance, so the problem is likely being compounded by opening the throttle more to get past the sluggishness. I don't have any hard proof of this, but I think there's also enough hysteresis in the temperature gauge that this could still be happening even when you see three bars. Two bars would just mean it's become bad enough to pull the gauge down a notch.

Your sensor problem may be indirectly related to this if the off-normal fueling causes you to put enough load on the engine in situations where the ECM notices that one of the knock sensors isn't cooperating. The thing is, the ECM wouldn't be throwing a code if there weren't a problem somewhere between it and the sensors.

I'd recommend you do these five things:

1. Strip off the plastic.

2. Check all of the wiring around the knock sensors for heat damage and do the continuity checks in the manual, jiggling as many parts of the wiring as you can to make sure nothing's gone intermittent. Cleaning the connector contacts wouldn't hurt, either.

3. Replace the thermostat. You'll want to do this no matter what, because the engine [-]may[/-] will not run at its best even in warm weather if the coolant never stops circulating.

4. Put the plastic back on, enjoy the better fuel economy and performance and wait until high summer to see if the ECM complains about the knock sensors again.

5. If it does, go find a replacement ECM. The old one is in the tail of the bike and all you need to do to replace it is remove the seat, so no additional removal of the plastic is required. The bad one will continue to run the engine as long as none of the critical sensors (crank and cam position) fail.

Everything I read, in almost every case on the forum groups, seems to indicate almost every time with the same symtoms I have to be a ECM.

There's a good chance that it is, but I wouldn't replace it until the other possibilities have been ruled out.

--Mark

 

[Redfish]

Post #33 by Blrfl is just perfect. I 100% agree with everything he said.

The ECU should be available new by now, I had trouble finding one but I am sure they did not stop making them.

 

[st1300r]

Short story, what blrfl said.

When you pull plastic the 1st post in this thread will help. It's not a big deal. The 2nd time you'll just throw the fiddly bits in a coffee can.
Push the center of the flat plastic rivets in then pry them out. (like the ones on the inspection covers for oil fill and rad fluid)
Push the center of them up past flush to reset them to put them back in. Then push them flush to lock them.
Don't be surprises if some are broke. Functional replacements are at lowes.
Pull the center of the large ones to release them like under the chin of the lower fairings.
Don't be surprised if they are broke. Tie wraps work fine.
Slap the mirror covers outside edge forward they'll pop off. Align the 3 prongs with the holes and slap it towards the center of the bike they'll pop back on.
Align and engage the small tabs of the 2 major fairing pieces up at the light housing end and hold it there until you get a bolt in to hold it in place.
That's about as complicated as I can make it.

3 bars on the t-stat at 10?f on the hiway. 3 bars stuck in traffic jam at 104?. I don't recall anyone reporting other than 3bars with a functioning t-stat. Easy fix you need one. Unless you tried to make it sound like a coffee can full of nuts and bolts with a tank of 87 I don't see it doing anything other than exercising the knock sensors.

 

[wjbertrand]

Engines are more susceptible to knock at higher running temperatures, so it makes sense that you're not seeing the FI light until the engine gets hot enough to show three bars on the temp gauge. I think the faulty thermostat is causing the somewhat confusing intermittent behavior of the light. There is still I believe an underlying issue with the knock sensing circuit. With a correctly operating thermostat and consistent running temperatures at 3 bars, the behavior of the FI light would likely be more consistent with previous reports where it sets whenever 4,000 RPM is exceded.

 

[troykahack]

Ok, I'm convinced I need a Thermostat and O-Ring.... On Order... will change and update after. I will also try the other procedures to wire around the knock sensor. I read in another thread that you can run the bike on the road without the plastic, is this true for testing purpose? As far as the bars go, I have only seen it go to four bars one time and it was just for a short moment on a very hot day at idle around a lot of other hot bikes, I should have not mentioned it. The two bars was just the one night when outside air temp was in 40's, and if moving, it would be less.... feels like temp?

I checked Ebay for a used ECM and no luck. I looked for a new one and have not found any in stock but the current price seems to be $1200. I am sorry, I am just not going to drop down this much money to fix this 03 bike. I can part it out or trading it in seems for more money. It has over 42k miles. Still looking for a used ECM. Even if someone has one which set the 25 code consistently will be helpful, other than possibly not giving mine a chance to set the 26? Might just muck up things more. If anyone can find one at a more reasonable price, please let me know.

Amazon has one for $1025 and PartsZillia $690 ... both say in stock... not sure I want to put over $700 into the ECM yet?

Part number 38770-MCS-L01

FOUND ONE ON EBAY, PLEASE DO NOT BID AGAINST ME.... LOL

Ok, now I need help. The one on ebay has correct part number but he list as only compatiable with Goldwing 1800. I wonder if it is correct picture or not. But it says it is not compatible with my bike?

http://www.ebay.com/itm/2006-Honda-st1300-st-1300-A-OEM-ECU-PGM-FI-Unit-38770-MCS-L01-/191547502030?hash=item2c991eedce&vxp=mtr

Also found one in the Netherlands after exchange and shipping is $302 US. It is from 2006 -02 ST1300A same part number. It indicates it is for USA Model. I assume this one will work.


Again, thank you on this forum. Please notice I am now a site supporter again. It is worth it.

Rory

 

[Blrfl]

I read in another thread that you can run the bike on the road without the plastic, is this true for testing purpose?

Testing and actual riding if that floats your boat. I take mine out on my usual check ride all nekkid after I do major service. Just re-install the mirror housings so you have front turn signals and running lights. If you don't disconnect the sensor from the harness (I unscrew mine from the inner cowl), tuck it someplace out of the way.

The two bars was just the one night when outside air temp was in 40's, and if moving, it would be less.... feels like temp?

The "feels like" temperature doesn't affect the bike, but you will start to see two bars at about that temperature when you're moving.

It has over 42k miles.

Finish breaking it in before you try to sell it. Seriously, 42K isn't much for an ST of any flavor.

--Mark

 

[troykahack]

Birfl

Thanks.... I have not been able to EVER get it to set a code on the Center Stand, don't know why unless it is load related?

Thanks for info on Feels Like temp.. I will put that one into my memory banks for future reference. So, you say 2-3 bars is normal? Do you think the Thermostat is a problem? I have one on order. I have been checking it on the center stand in Garage a bunch and it hops up pretty quickly to 3 bars now. Just that one night I saw two bars. It's now a normal Florida Spring Humid Heat kicking in.... now, after the bike finishes the warm up and rpm drops, it is at 3 bars in short order. I just really wonder if the Thermostat is bad but I plan to change and you can test it I know.... have done it for cars before.

I found a ECU ECM used one in stock in the Netherlands, and sent a note to the seller on Ebay for the other one. It was actually on there last week and didn't sale. I think he has it marked wrong or his matrix table is wrong. If the picture is of the actual ECU ECM, it appears to me to be the correct part number. I sent him a note to ask. His description is for 06 ST1300A. I do not have ABS but don't think it makes a difference.

This bike was a friend of mines and he passed away and I bought it from his wife. It was stored in a outdoor barn/garage.... it was out of direct exposure to weather but was not like putting the bike in my garage. I have had a lot of gremlins because of the storage issues although he rode it up to a week before he passed. Having a possible connection problem is not out of the question. But I am one of those people who don't mind having a spare this and that in guess needed. People on this group are awesome. When I first got the bike, I thought I had a U-Joint or drive shaft joint problem based on the noise while riding. Dave from Jacksonville rode down to my house to help me diagnose and I had special tools to change the parts and he also needed the tools, that were sent to me by another participant on this site. It turned out my bearings in both wheel hubs were falling apart and the joint was fine. It was awesome help from members of this group. I guess this is off topic but I am third owner, first owner would like the bike back, but I am like you, it only has 42k miles, has a long way to go.

I have confirmed with Ebay seller that his matrix is wrong and it is a ECM for a 2006 ST1300A. Please don't bid against me, lol. I promise if it doesn't fix my problem, I will be glad to share openly with all later if needed for trouble shooting purpose. This has been on Ebay for a few weeks but because his matrix is wrong, I didn't bid on it. So it has made is several weeks without a bidder. But it is priced at $299.00.

Thanks again,
Rory

 

[playinatwork]

Put me on the side of the fence that says the ECM is fine. I think if you replace the thermostat and ride it, it will be fine. By the way, mine has seen nothing but 87 octane for the last 143,000 miles.

 

[Redfish]

Once it warms up it should show 3 bars. Always.

I did not ride it much when the temp was below freezing but once warmed up it always showed 3 bars.

I rode it often when it was very hot and it always showed 3 bars. On Hwy 287 in Texas at 101F and 80+mph it showed 3 bars. At the top of Pike's Peak when the HD and the GoldWing following me were both running hot, it showed 3 bars.

The only time it failed to show 3 bars was when the T-stat was bad.

 

[troykahack]

playinatwork,

Hey, you are close enough we can almost play swap ECU's... you game... LOL

Rory

 

[Blrfl]

I have not been able to EVER get it to set a code on the Center Stand, don't know why unless it is load related?

There are too many variables, which is why I keep urging you to inspect the wiring and clean the connections. It could be something as simple as a connection on one side going bad as it's heated and the ECM noticing that it isn't hearing knocking on that side as a result. I don't have any special insight into how the FI system on the bike is implemented; all I can go by is what's in the service manual and some informed guessing about how things should work if they were designed by sane people.

So, you say 2-3 bars is normal? Do you think the Thermostat is a problem?

One bar is warmed up enough to ride, three is normal operating temperature. If you see two bars any time other than on the way up to three, your thermostat is stuck open or you're riding in extremely cold temperatures. Stuck 'stats are almost a rite of passage on early bikes. I've been through it myself with my '04.

I have been checking it on the center stand in Garage a bunch and it hops up pretty quickly to 3 bars now. Just that one night I saw two bars.

The radiator doesn't exchange much heat when there's no air flowing through it, so your bike should warm up to three bars when idling and the fans should run periodically. You probably don't see cold temperatures often enough for it to become visible on the temperature gauge, but the side effects are still there in warm weather. Ten bucks says you'll pull the old 'stat out of the housing and you'll discover immediately that it doesn't need to be tested.

I found a ECU ECM used one in stock in the Netherlands...

Run away from that one. The ECMs on bikes sold outside North America have an immobilizer feature that will not run the engine without a chip reader mounted in the ignition switch and a chipped key that it has been programmed to recognize.

There's a web site called the Motorcycle Salvage Network that can probably find you a domestic ECM.

--Mark