1985 FI gl1200 limited

[Jamesjines]

Ok, I’m hoping someone here can help me. I just bought this 85 limited goldwing and I feel like maybe it was a bad idea even at $800. It runs(ish) and rides. Has an alternator, and it’s fuel injected. Appears to have been setting for several years to me though.
Issue:
running very rich, poor fuel mileage, black smoking.

What I have tried this far:
Tested the Throttle position sensor, it’s good. Fresh good fuel, new plugs(multiple times in 24 hours), fuel pressure tested good, all 4 cylinders are getting good white and blue spark, tested for vacuum leaks none found.

Is there something I am missing? Is there a way to adjust the fuel ratio? I don’t know anything about these FI bikes, and I really just want to be able to ride this year.

[Rednaxs60]

Welcome. These '85 Limited Edition FI bikes are a great ride when you get them sorted out. First priority is to get the OEM service manual, Electrical Troubleshooting manual, and the supplement. Without these you can easily go down the rabbit hole so to speak. The supplement is the most important to have.

Tested the TPS - how? The supplement provides instructions for this. The alternator mod is a good - have done this to mine some 5 years ago. Injectors may need to be cleaned, not much else to do, the CFI system takes care of fuel and timing automatically.

If you have not set the TPS, or have checked it to make sure it is within spec, make sure that when you do you do not move the stop screw. It is set at the factory and never to be moved. You move the throttle linkage to the stop screw by backing off on the idle screw. After you check the TPS, and or change to be in spec, you adjust the idle screw to where it was and tweak as needed. Ask me how I know, BTDT.

You may have to balance the cylinder banks. You cannot balance the cylinders on the same side, can only balance the left/right cylinder banks. I use #3 and #4 cylinders to do this, easiest to get at, and only need two vacuum gauges. The screw for this is under the right side CFI cover. Only use this screw to balance the cylinder banks with vacuum gauges attached. Don't adjust at any other time. When you balance the cylinder banks, you may have to adjust the engine idle as well.

Having mentioned the above, I would say the TPS is probably out of spec, or has been set improperly. Check this first.

PM sent.

Cheers

[Jamesjines]

Thank you for the reply, I replied to your pm as well. I’m looking at the TPS units I see online, and they don’t look like mine, mine is just round with no bolt holes or anything, it’s only held in by the washers on the two mounting bolts, so I’m assuming that that means it is the wrong one. I don’t know how tps systems work, could it be as simple as the wrong tps gives a different signal? Also, if I were to unplug the tps, and start the bike, would that tell me anything? Thanks again, Jamesjines

[Jamesjines]

UPDATE!! Today I decided to tinker around a bit. Didn’t do much, cleaned the new plugs, put them back in, started it and let it run. It idled decently with minor pops every once in a while out one tail pipe, let it get up to operating temp, the cooling fan kicked on, I hoped on and went for a ride in the cold. But it runs out extremely well when it is at operating temp. Only issue it gave me was when you very first twist the throttle it stutters a tiny bit. Very light black smoke under hard quick acceleration. I just bought the bike yesterday, my last was an 04 shadow aero 750 and yesterday this goldwing was way weaker. Today, it way more powerful. The only difference is the temp of the bike. I don’t know if that helps or not, just thought I would share.

[Rednaxs60]

Thank you for the reply, I replied to your pm as well. I’m looking at the TPS units I see online, and they don’t look like mine, mine is just round with no bolt holes or anything, it’s only held in by the washers on the two mounting bolts, so I’m assuming that that means it is the wrong one. I don’t know how tps systems work, could it be as simple as the wrong tps gives a different signal? Also, if I were to unplug the tps, and start the bike, would that tell me anything? Thanks again, Jamesjines

Good to hear you took the bike for a ride. Unplug the TPS and nothing will happen, will not start - you would have the "FUEL SYSTEM" indicator light on the dash come on and there would be an error code on the ECU. If the FUEL SYSTEM indicator light ever comes on, do not turn the key to the off position. Look for the error code on the ECU. If you turn the key to the off position the error code will be lost, the ECU does not store any error codes.

The TPS you have is the original one. These are no longer available. If the one on your bike fails you have two options, find a used original or install an aftermarket one.

[Jamesjines]

Ok, so new update, I don’t know if I should just keep updating here or make a new thread. Idk how all this works so sorry if I’m doing it wrong. But here’s what I have found today. I ride it about 20-30minutes and parked up for 2-3hours, went back out and everything was still doing really well! I was thinking maybe it was just dirty injectors or something. Well I rode another 20-30 minutes and parked up again. This time I waited about 5 or 6 hours and when I just now went to start it to put it in the garage, it was back to chugging black smoke and has a high idle, around 1800rpm. So it’s only really doing it when it’s cold and been setting for several hours. I’ve been looking thru the manuals and I can’t see anything about an auto choke or anything so what could it be? Faulty Ecu?

[Rednaxs60]

Ok, so new update, I don’t know if I should just keep updating here or make a new thread. Idk how all this works so sorry if I’m doing it wrong. But here’s what I have found today. I ride it about 20-30minutes and parked up for 2-3hours, went back out and everything was still doing really well! I was thinking maybe it was just dirty injectors or something. Well I rode another 20-30 minutes and parked up again. This time I waited about 5 or 6 hours and when I just now went to start it to put it in the garage, it was back to chugging black smoke and has a high idle, around 1800rpm. So it’s only really doing it when it’s cold and been setting for several hours. I’ve been looking thru the manuals and I can’t see anything about an auto choke or anything so what could it be? Faulty Ecu?

The engine should have a fast idle, this is controlled by the ECU. Faulty ECU and the engine probably would not start - put that to rest.

If the idle is up around 1800, the engine should be operating smoothly, even if there is smoke out the exhaust. Is this what you mean?

Black smoke or oily smoke? Does it clear up after a minute or so? Did you have the bike on the side stand? Does it idle down when it starts to warm up? Is the idle at operating temp set to 1000 RPM +/- 100 RPM? What can happen is oil leaking into the cylinder(s), and when you start the engine, a plume of oily exhaust appears.

I have a small inexpensive borescope that I use to look into the cylinders through the spark plug holes and I can view what is in there.

Being these are older bikes, a compression test would be good. The lower the compression the more likely there is leak by the piston rings and or valves. The exhaust valves may have carbon deposits between the valve and valve seat. The intake valves and seats are generally in good condition. You can have weak piston rings as well.

These engines will perform with compression down in the 100 PSI range.

More information is needed. There is no quick fix with these FI models.

Good luck.

[Jamesjines]

It sets on the side stand as I’m not able to get it up on the middle stand by myself, I guess I’m just not strong enough? I’m 6’5 and nearly 300lbs lol. It black smokes and smells like gas, burns the eyes. It does it until it get up to temp. At temp it idles right at 1000. And yes even with all the black smoke, it does run quite smooth. For Compression, the biggest difference is #4 at 150psi and #1 at 160psi. If any more info is needed, just ask. I’ll do anything I can.

[Rednaxs60]

Compression in #1 and #4 is pretty good, what are #2 and #3?

Hopefully the cylinder banks are balanced. If you don't have any vacuum gauges, you can get an indication of cylinder bank balance by using a heat gun, the small ones from Harbor Freight, and check the exhaust header temps. All cylinders should be close, if not, adjust the balance screw that is just behind the right side CFI cover. This will do until you get a set of vacuum gauges. If you adjust the cylinder balance screw, take note of what you do, 1/4 turn increments would be good. May have to adjust the idle as you do this. Keep a log of this for later, remembering exactly what has been done seems to fade as time goes on.

You're correct, seems to be too much fuel at start. Since fueling is controlled by the ECU, I would suggest the TPS is out of spec and/or has been calibrated incorrectly.

What I would do is back the throttle linkage off until it is at what would be "0" RPM. Take note of how many turns so you can reset the throttle afterwards. Take note of the stop screw position for future reference. The throttle linkage should back off totally without contacting the stop screw.

In the supplement, there is a procedure to set the TPS to spec. In the supplement, starts on page 10-24, the setup procedure is listed.
Word of caution, do not adjust the stop screw, under "Notes" on page 10-25. Set the TPS to spec, try for the 0.475 V (.474 V to 0.476 V. is good) This should get rid of the fuel smell.

If the TPS securing bolts are still as per factory install with the break away heads, use a dremel to cut a slot in these to remove. I replaced mine with hex head bolts. May have to file the outer edges of the new bolts to fit. Takes a few tries to get right because when you tighten the TPS it may move the setting a bit.

The manual calls for an in line calibration harness. To do your own test harness, attach a wire to each of the three wires from the TPS, 18 Gauge is good. When finish leave installed and tuck out of the way. I made mine long enough that I could route these up and under the shelter by the air filter for future use.

Good luck.

[Rednaxs60]

Another option is to go with a one wire setup. This is an alternator that only has an output wire to the electrical system - can hook directly to the battery. This wire doubles as the sense wire and power to the alternator. No extra wires to consider.

[Jamesjines]

Compression in #1 and #4 is pretty good, what are #2 and #3?

Hopefully the cylinder banks are balanced. If you don't have any vacuum gauges, you can get an indication of cylinder bank balance by using a heat gun, the small ones from Harbor Freight, and check the exhaust header temps. All cylinders should be close, if not, adjust the balance screw that is just behind the right side CFI cover. This will do until you get a set of vacuum gauges. If you adjust the cylinder balance screw, take note of what you do, 1/4 turn increments would be good. May have to adjust the idle as you do this. Keep a log of this for later, remembering exactly what has been done seems to fade as time goes on.

You're correct, seems to be too much fuel at start. Since fueling is controlled by the ECU, I would suggest the TPS is out of spec and/or has been calibrated incorrectly.

What I would do is back the throttle linkage off until it is at what would be "0" RPM. Take note of how many turns so you can reset the throttle afterwards. Take note of the stop screw position for future reference. The throttle linkage should back off totally without contacting the stop screw.

In the supplement, there is a procedure to set the TPS to spec. In the supplement, starts on page 10-24, the setup procedure is listed.
Word of caution, do not adjust the stop screw, under "Notes" on page 10-25. Set the TPS to spec, try for the 0.475 V (.474 V to 0.476 V. is good) This should get rid of the fuel smell.

If the TPS securing bolts are still as per factory install with the break away heads, use a dremel to cut a slot in these to remove. I replaced mine with hex head bolts. May have to file the outer edges of the new bolts to fit. Takes a few tries to get right because when you tighten the TPS it may move the setting a bit.

The manual calls for an in line calibration harness. To do your own test harness, attach a wire to each of the three wires from the TPS, 18 Gauge is good. When finish leave installed and tuck out of the way. I made mine long enough that I could route these up and under the shelter by the air filter for future use.

Good luck.

Ok. The other two cylinders are 155 and like 153 so all are pretty close. As far as the TPS goes, I got to mess with it a little bit I done it before starting the bike today just to see if there was a difference, and here’s what came after. I couldn’t get .474-.476 I could get just above or below it so I went with .478 I have big Hands and couldn’t quite adjust it well enough to get it to that precise point after about an hour I set reels for close considering it was at like .382 I figured if anything it had to be better than it was. I will try to adjust it down tomorrow when I have more time. It’s in the high 20s low 30s here so I don’t mess around outside after dark lol. And I was right it’s much better. I coughs black smoke for maybe 20 seconds after startup now and has much better throttle response as well as much more power in the lower rpms. I do have to readjust the idle some as now it idled at about 1180-1200 when warm 2000 when completely cold. After those two minor adjustments, I am just going to ride the heck out of it and use fuel injector cleaner in every tank for a few weeks and see where it goes. I will report back with any changes. Thank you very much for your time and effort to make this job much much easier on me.

[Rednaxs60]

Love it when a plan comes together. Ride it like you stole it - won't hurt it! Cheers