1985 LTD Loss of Power

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Rednaxs60

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Victoria, BC,
Went for a 4 day tour of our lovely BC province with a very pleasant passenger. Took the '85 LTD of course as I have been working on it to get it so I could tour with it. All went well, bike ran well, and it was lovely weather. Went through Trail, BC then headed up the mountain to Rossland, and on to Strawberry pass that is about a mile up. All was going well but I noticed the bike was staring to run hot.

Started through Strawberry pass and lost power. Bike would start but would then quit. Baffled me and the only thing to do was to let it sit and contemplate a strategy.

I let it sit for some 45 minutes or so, but during this time I was able to start it but it would stall immediately. I noticed the fuel pump sounded different as if it was cavitating.

After letting it sit and cool down, started it up and it sounded not bad and kept running. Made the decision to carry on. Sonya was a bit stressed but not a lot we could do.

Rest of the way into Osoyoos and on to Princeton was uneventful, but I listened very intensely to how the bike was operating. Made it to Princeton for the night.

Left Princeton this morning and the bike ran well, and no more hiccups. There was a noticeable change in the sound of the bike about half way through Manning Park for the better. Ran from Hope to the BC ferry terminal at Tsawwassen. Bike also started to idle where I had set it some time ago.

Now for the mystery. These fuel injected bikes are extremely power sensitive and need a lot. I had noticed that the voltage showing on the dash gauge would reduce as the rpm got higher, but return to 13.8 VDC (14.4 VDC at battery - only look for consistency when it comes to gauges). I noticed today that it was consistently 13.8 VDC and the bike was operating well and the sound of the engine was as I expected.

I have the alt mod on my '85 with a pulley ratio of 1:2 - 4' pulley at crank and 2" pulley on alt. I have read where alternators operate in a range up to approximately 9K RPM. I also know that alternator output is not linear, in that an alternator will go to full output say around 6K to 7K RPM then start to fall off. With the charging systems designed today, if one of the components of the charging system is not keeping up then you can have issues. I'm thinking that the alternator RPM was such that I was actually discharging the battery as I was keeping the RPMs high because I was travelling two up through the mountains.

With this in mind I'm thinking of changing the alternator pulley to a 3" pulley that will drop the alt RPM because I will now have a ratio of 1:1.5. I may even go to a 1:1 with either two 3" pulleys or two three inch pulleys.

The other aspect of this issue is the fuel pump and how it sounded when the bike first quit. It was very peculiar and I had not heard it sound this way before. I will be doing a fuel pressure test and looking at the fuel return/venting system. Have a fuel pump on hand.

I also have a wish list:

Battery to be load tested
Alternator to be taken in and checked
Check to make sure cylinders are firing
Check coil resistance/impedance
New plugs
New plug wires
Check for plug cap availability

Other than this the bike ran well and took the two of us for a good tour of BC.

Question - plug wires - are these resistance type or no and what size. Will find out but thought I'd ask.

Have to get this work done. Have another tour of BC on 19 June with my HD friends.

More to follow. Cheers
 
I was thinking gas cap vent myself. But if it is electrical - I'm wondering if charge may be going through both the alternator regulator and the stock somehow?
 
I would say approximately 700 metres, pretty substantial.

Have started to look at the bike. Checked the firing and think I have a lazy cylinder but it is firing - all plugs look the same, burning very well.

Taking the alternator in tomorrow to the shop. When I spin it hear some gremlins inside that I don't like. Also going to ask if he has a used 3" pulley that I can install as the crank pulley - bore needs to be 12 mm.

Don't think I need to load test the battery, but may do this just for peace of mind.

Let the bike idle in the hope that the rad fan would cut in automatically - no joy on this front. Thankfully I have a manual fan switch and it works quite well.

Have to track down a fuel pressure gauge and fittings to install in the right fuel rail. The new fuel pump I have is an Airtex E8312.

More to follow.

Cheers
 
Sounds like you may of just had a faulty alternator or slipping belt. The fact that voltage didn't increase as revs went up makes me lean more towards slipping belt.
 
Been doing some investigating and not a lot has transpired; however, just finished changing the fuel pump to an Airtex E3812 rated for pressure up to 90 PSI. Started the bike and it seems to be idling better, more on this later. Lots of fiddling to get it in the proper position because it is a smaller profile than the original.

Had the battery load tested and it was good. Took the alternator in and the bearings are being replaced. Have to get the pieces to do a fuel pressure test. Took the plugs out and the plugs look all the same.
spark plug colour.jpg
Colour of the insulator is white on all four - gives me a sense that all is well in the spark plug department.

Get the alternator back tomorrow and hopefully all is well.

Will keep at my investigation.

Cheers
 
Got the alternator back today, new bearings and output check is good, and no charge for the bearing work. Showing 13.7/8 on the dash voltmeter - 14.2 at the battery. As long as the dash voltage stays at 13.7/8 and is consistent, I can live with this.

With the new fuel pump installed idles very nicely. The cylinder firing sound is also better. Will have it out on the road later this week for a road test. Fuel system pressure test is next to make sure it is within spec.

Checked the rad fan circuit. Appears the switch is duff, ordered a Beck/Arnley 201-0817 out of Vancouver. $44.00 CDN delivered, better than the $112.00/$118.00 I was quoted from Honda. Should be here end week, early next. This may also be the reason I was seeing higher operating temperatures last year when I finished the alt conversion. Have a manual switch that I can use in the meantime.

With what I have checked and done, I'm torn between fuel and electrical. The bike would not have started if there was a lack of fuel or not enough juice; however, the bike may start but immediately stop if not enough fuel. I did note one issue that is worth noting. The travel computer will reset if the battery voltage is too low. This did not happen at anytime during the trip, nor when I was having the starting/running issue. Load tested the battery and it was good.

I'm also curious whether the altitude had something to do with the issue considering this is a fuel injected bike and the system should compensate for altitude. I was getting a lot of fuel smell and the only way to do this is to have the fuel returning to the tank instead of going to the cylinders. This is done by the fuel pressure regulator - from the schematic I think it returns fuel if the pressure is too high. This may also explain why the tank was under more pressure than usual.

The more I do to rectify this issue, and reflect back on what happened and the number of little things to consider, I'm tending to think it was a fuel related issue.

So my next investigation will be to check the fuel system pressure. I hope it is within spec.

The fuel system has several parts that may need to be looked at. The pressure regulator, air valve, reed valve, and of course the injectors. This may be a whole new discussion.

More to follow as I wrap this issue up.

Cheers
 
I was thinking of contacting Honda and ask for warranty on these issues, bike's only 33 years old!

Most of what I mention is for myself and good old maintenance requirements. Like to know how things work and interrelate.

Cheers
 
Got the bike back together and did a road test to the daughter and son-in-law. Seems to be working much better. It starts and idles better now that I have the new fuel pump installed. Had it for a higher speed run up to 125 KPH - 4100ish RPM and it worked well.

I am tending to lean towards a fuel issue. Can't say for sure but these high pressure fuel pumps can be on the way out but still work. I did notice when this issue occurred that the fuel pump had some extra noises when it was first cycled on.

The alternator and battery were tested and both were good, except for the bearings being replaced in the alternator.

Looking for some parts to use to do a fuel pressure test.Get at this soon.

Went to the local auto wrecker yesterday to browse for some used parts and ended up going away with a used fuel pump that was tested good. It was half the price of the new Airtex and will be a good spare. The pump I got - think it was off a VW - is identical to the original that I took off the bike in fittings, length and diameter. I would also submit that the pressure is similar because of the FI system. This does not surprise me because only so many manufacturers of these pumps out there. External fuel pumps are more of a rarity than the in-tank ones.

While I was doing this work, I mentioned that the thermo switch for the rad fan did not turn the rad fan on. I put the plug back on the switch, ordered a new one, a Beck/Arnley Rad Fan Switch 201-0817. Went to take temp readings of the bike to correlate with the temp gauge and when the temp indicated 6 bars, the rad fan came on. Guess I did not have the switch plug installed properly, regardless it is working now.

More to follow.

Cheers
 
Thanks. Reflection is a great thing especially when working on an issue. Before I left for the tour, I was always having to keep the revs up for a minute or so before the bike would idle at an acceptable level. I have also scoured the forums for information on this issue. On GL1200Goldwings forum there is a section specifically for the fuel injected bikes and it is there that I found information related to the fuel pump and poor operation of the FI bikes. A fuel pump on the way out can provide the proper pressures when tested but under load and while riding the pressure can drop to a level that will cause a loss of power. This is similar to an electrical/electronic issue where the issue eludes oneself until it fails completely. When this happened and I had time on the road to think about it, and with the noises from the fuel pump, my instinct was that the fuel pump was going, and I believe now that my thoughts were correct.

I also found references to the idle air valve in that it gums up after so many years of operation and this affects idle at start and when operating. This is on my list to be looked at as well.

Another issue that was mentioned is the smell of gas on start and this can be directly related to the fuel injectors.

One last item of note is the fuel pressure regulator. Don't know if this can be adjusted, cleaned or maintained, but one person on the GL1200Goldwing forum mentioned that an FPR from an 85 to 88 Chevy Sprint 1.0L turbo is a direct fit and replacement for the FPR on an '85/'86 FI Goldwing.

More to follow.

Cheers
 
Further to my last, I tok the bike out of the garage this morning, started it and the idle was at 960 rpm (acceptable) then climbed to 1150 or so because of the fast idle aspect. Much better operation at start up. Everything being done is making this a very nice ride.

Cheers
 
I have an 85 LTD with a poor boy conversion also. Electric problems for me went away and your not going to overrun the alternator output with speed unless the field slip rings are no longer round and brushes are jumping. My fuel pump got replaced at 90,000 and I had to rig up a replacement with a generic frame mount high pressure one I got from NAPA for about 120.00 could not find OEM Mine has also needed a fuel filter replacement.


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I just looked up your fuel pump and the Airtex E 8312 is an in tank pump pump. Specs look adequate for port injection so it may work. My factory pump was on RH side above foot brake under a little chrome cover. Don't know if our fuel sending units have ability to change to in tank design


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Didn't read the fine print. If it is an in tank fuel pump I don't think the electrical connectors are conducive to this. Regardless the pump does work well. If you go to a wrecker you should be able to find a direct replacement for the OEM fuel pump - only so many manufacturers of these pumps out there. I would also submit that the system pressure for an FI system is similar between all vehicles. There are more in tank fuel pumps then external. I wouldn't want to change to an in tank fuel pump. Too large and a hassle.

I also fixed the fuel low level indication as well by replacing the thermistor that is integral with the fuel sending unit.

I replaced my fuel filter with a Beck Arnley 043-0897. Larger but was able to make it fit in the original holder, working well. Unless you are familiar with the original size fuel filter, non the wiser.

Cheers
 
Got some 500 or so Kms on the new fuel pump install riding solo and two up, up some smaller mountains here on Vancouver Island. Working well. Have a 5 day tour through the interior of BC up to the Columbia ice field(s) and down to Osoyoos and back. Will post after that trip as to the performance of the bike.

Have 4 refurbished injectors coming this week, very good price, Autoline 16313. Will install this weekend. These are direct replacements for other injectors such as SMP FJ267.

As this is an older bike and we have to be inventive regarding parts and such, looking for a TPS (have the information on the work around), fuel pressure regulator.

Always something to research and look into.

Cheers
 
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