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Surge and idle problem of 1800 GL

Posted: Tue Aug 07, 2018 7:32 am
by Lasalle
Since last Sunday, my 2001 GL 1800 (6,600 mls) surges to 1200 rpm after a cold start, then works itself down to about 900/700 rpm, then dies. When started warm/hot it dies after a few seconds trying to get higher than 400/500 rpm.

I did a 260 mls round trip last Sunday, and everything was fine for most of the day until I noticed a short stutter and the "FI" light came on, but didn't start blinking. Immediately after that, I stopped on the shoulder of the road. Of course, the engine died right away. Starting was no problem, but after 2 seconds the engine went out again. Heading home, I had to get gas after experiencing an unusually high consumption. The mileage/gallon dropped by about one-half.

I read a lot on this forum about similar problems other subscribers had, like for instance, loose hoses, malfunctioning IAC, etc. However, there was no mention (at least on all the posts that I read) of an increased gas consumption after the "FI" light came on.

Has anybody experienced the same problem in the past, and if yes, what was done to take care of this particular problem?

Re: Surge and idle problem of 1800 GL

Posted: Thu Aug 09, 2018 7:33 am
by GoldWingrGreg
While out riding and the next time the FI light comes on, pull over, put in "N", and put the side stand down. Do not cycle the key to the off position until your codes are recorded. Because you are now not moving, and the side-stand is down while the FI light is on, that triggers the ECM to flash trouble codes.

The FI light should start flashing a code(s). Have paper and pen handy in case there are more then one. If there are more then one, and if your count is not correct at first, that's ok, the codes will continue to flash until the key is turned off, so take your time and count them correctly.

- short flash = 1
- long flash = 10
- between codes is a noticeable longer pause

So, for example: 2 longs and 6 shorts equals 26. Long pause, 1 long and 3 shorts equals 13.

Go get your codes and post them back here. Because of your year, and it wanting to die, most will say if they play with the throttle they can keep it running. Some will say they didn't think they were gonna make it home, to my knowledge, the above is true and they all made it back home. I'm sharing that so that you know that you'll make it home too.

Re: Surge and idle problem of 1800 GL

Posted: Thu Aug 09, 2018 10:43 am
by Lasalle
Thanks a bunch Greg! I'll go with your suggestion. Just one question before I do: do I have to keep her running after pulling over? She'll certainly die.

Re: Surge and idle problem of 1800 GL

Posted: Thu Aug 09, 2018 11:14 am
by Techdude2000
Lasalle wrote:
Thu Aug 09, 2018 10:43 am
Thanks a bunch Greg! I'll go with your suggestion. Just one question before I do: do I have to keep her running after pulling over? She'll certainly die.
Yes

Re: Surge and idle problem of 1800 GL

Posted: Thu Aug 09, 2018 11:59 am
by Lasalle
Ok, will do. Thanks!

Re: Surge and idle problem of 1800 GL

Posted: Thu Aug 09, 2018 3:16 pm
by AZgl1800
the throttle must remain in Idle position though.

if you open the throttle, it cancels the FI mode light sequence.

Re: Surge and idle problem of 1800 GL

Posted: Thu Aug 09, 2018 3:49 pm
by Lasalle
Thanks for pointing that out! I am 100% sure that the engine will die, but I'll give it a try this weekend.

Re: Surge and idle problem of 1800 GL

Posted: Thu Aug 09, 2018 3:53 pm
by Lasalle
Thanks for pointing that out! I am 100% sure that the engine will die, but I'll give it a try this weekend.

Will FIXD be able to diagnose the GW?

Re: Surge and idle problem of 1800 GL

Posted: Sat Aug 11, 2018 10:15 am
by Lasalle
Ok, I did as suggested and found 2 long and 5 short flashes, confirmed 3 times, which equals "Code 25". Here is what I found on this forum:

25 Blinks • Engine operates normally
• Loose or poorly connected right knock sensor connector: • Open or short circuit in right knock sensor wire: • Faulty right knock sensor.

The above sounds good, except for "Engine operates normally". It doesn't! It tries to die after a stop and there is gas smell that wasn't there before. Someone pls advise!

Re: Surge and idle problem of 1800 GL

Posted: Sat Aug 11, 2018 11:51 am
by Techdude2000
Lasalle wrote:
Sat Aug 11, 2018 10:15 am
Ok, I did as suggested and found 2 long and 5 short flashes, confirmed 3 times, which equals "Code 25". Here is what I found on this forum:

25 Blinks • Engine operates normally
• Loose or poorly connected right knock sensor connector: • Open or short circuit in right knock sensor wire: • Faulty right knock sensor.

The above sounds good, except for "Engine operates normally". It doesn't! It tries to die after a stop and there is gas smell that wasn't there before. Someone pls advise!
This means you need a new ECM. Bad running with a 26 or 25 code is a bad ECM about 99.9% of the time. It’s getting to be a very common failure for the early 1800s. This is the original part number, it will probably be subbed to a new number when ordered. #38770-MCA-671

Re: Surge and idle problem of 1800 GL

Posted: Sat Aug 11, 2018 12:26 pm
by GoldWingrGreg
Techdude2000 wrote:
Sat Aug 11, 2018 11:51 am
This is the original part number, it will probably be subbed to a new number when ordered. #38770-MCA-671
Yes ... it will have Honda's current part number on it, but when you take it out of its package, the ECM will have another number on it.

Current part number on package 38770-MCA-P00
Part number on ECM 38770-MCA-305

Go figure that one out.

Re: Surge and idle problem of 1800 GL

Posted: Sat Aug 11, 2018 12:41 pm
by Lasalle
Thanks Guys! Your input is highly appreciated! Now, one last question: I checked pricing on a new ECM, the cheapest running around $591 (hurts!!!!!). But if I get a smooth running GW back, it should be more than worth it. Now, I asked 2 sellers the question if there needs to be some programming or key chip exchange done. A Honda dealer answered that the ECM is "plug & play, while a parts supplier thinks that a Honda shop needs to program it. So, who is right? Did anyone of you install a new ECM and knows what (doesn't) need(s) to be done?

Re: Surge and idle problem of 1800 GL

Posted: Sat Aug 11, 2018 1:34 pm
by Techdude2000
It’s plug and play, no programming except you will need to initialize the new one. It’s easy, you get it installed and before you put the shelter back on, start the bike cold, don’t touch the throttle, let it idle until the fans come on, then shut it down by turning the key off. Restart it and it should idle smoothly at 700+/-70 rpm. If everything seems to work at this point, reinstall the shelter and ride it like you stole it!

Re: Surge and idle problem of 1800 GL

Posted: Sat Aug 11, 2018 3:56 pm
by Lasalle
Thanks a bunch! I'll let Y'All know how it went after I am done.

Re: Surge and idle problem of 1800 GL

Posted: Wed Aug 15, 2018 6:47 pm
by Lasalle
Today, my new ECM arrived and I installed it. Using the instructions of TechDude, I got it to work as it should. It went exactly how he described it will. My thanks go out especially to TechDude, and everybody else who chimed in! I saved a s***load of money by not having to take it to the shop. What a great forum!

Re: Surge and idle problem of 1800 GL

Posted: Wed Aug 15, 2018 7:24 pm
by Techdude2000
Lasalle wrote:
Wed Aug 15, 2018 6:47 pm
Today, my new ECM arrived and I installed it. Using the instructions of TechDude, I got it to work as it should. It went exactly how he described it will. My thanks go out especially to TechDude, and everybody else who chimed in! I saved a s***load of money by not having to take it to the shop. What a great forum!
Great! You’re welcome, glad you got her going again.

Re: Surge and idle problem of 1800 GL

Posted: Sat Sep 01, 2018 10:35 am
by Rwilkerson
Have not had that problem yet, but many thanks for that information. When it comes to problems I think many of us get a mental block otherwise known as a "brain fart" and really helps for someone to clear the air! Pun intended.