tps reading 1200 ltd


Information and questions on GL1200 Goldwings (1984-1987)
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finkeel
Posts: 2
Joined: Tue Nov 21, 2017 3:29 pm
Location: Deland Florida
Motorcycle: 1985 gl1200l limited edition

tps reading 1200 ltd

Post by finkeel » Mon Dec 04, 2017 8:33 pm



I'm new to fuel injection and just learning to read wiring diagrams and multimeter's. Electrical systems are my weak point. I was pleased with the way my tps checked out and adjusted, until I checked the output voltage between the white and green leads wile rolling on the throttle ,,, the voltage dropped instead of climbing. The bike runs but has a flat spot in the throttle roll on. Any idea on what's going on or what the heck I did wrong??
thanks



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Rednaxs60
Posts: 1336
Joined: Wed Nov 18, 2015 12:44 pm
Location: Victoria, British Columbia, Canada
Motorcycle: 1985 GL1200 LTD, 2008 GL1800

Re: tps reading 1200 ltd

Post by Rednaxs60 » Mon Dec 04, 2017 10:38 pm

Just checked the TPS readings on my bike.

With key on: positive lead to red - negative lead to green: 5.0 VDC

With key on: positive lead to white - negative lead to green: voltage increases smoothly

With key on: positive lead to white - negative lead to red: voltage starts at approximately minus 4.8 VDC and decreases to 0 VDC when throttle applied. Switching the positive lead to red and negative lead to white should only change polarity on meter.

I suggest you have hooked your leads connected to the wrong wires.

There can be a flat spot after 34 years. It is probably from wear on the internal TPS connections. Unless the TPS fails, I would not be too concerned. These TPS units have been discontinued; however, there are workarounds. I expect the flat spot is somewhere in the 2400 RPM range. These bikes like to be in the power band, 2900 RPM and above. May sound and seem that the engine is revving high, but with a red line at 7500 RPM, you're not even half way there.

Another bit of system maintenance that you should do is to clean the throttle plates with carb cleaner, and balance the right and left side cylinders. You cannot balance the two cylinders on the same side because the bike is fuel injected. This will make a difference in how the bike responds to throttle roll on.

Do you have the manuals. See PM.

Hope this helps.
"When you write the story of your life, don't let anyone else hold the pen"

Ernest

finkeel
Posts: 2
Joined: Tue Nov 21, 2017 3:29 pm
Location: Deland Florida
Motorcycle: 1985 gl1200l limited edition

Re: tps reading 1200 ltd

Post by finkeel » Tue Dec 05, 2017 12:31 am

I will recheck everything, your most likely correct since I get nervous working with electricity! Thanks for your help.

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Rusty Bike
Posts: 340
Joined: Sun Feb 28, 2016 1:55 pm
Location: New castle, PA
Motorcycle: 86 GL1200 SEi, 98 Valkyrie Std, 78 Yamaha XS750SE, 86 Honda XL125, 4.5 HP belt drive Minibike my dad built, foot clutch!

Re: tps reading 1200 ltd

Post by Rusty Bike » Tue Dec 05, 2017 3:11 pm

I replaced my TPS with the BMI unit and Saskariders aluminum addapter puck. I still have the flat spot. Bike runs like **** below 3,000 RPM. I also purchased 2 PB sensors from Ebay. These are actually 86 Honda Prelude MAP sensors. They look identicle to the OEM PB but the bike will not run right when installed. So i put the OEM PB's back in. Just took it for an extended test ride yesterday. This thing runs great when I nail it but not so good at crusing speed. I did find that the coolant temp sensor reads high by about 1.6K ohms when cold. But I tested it again with engine hot and it drops to .2K like the OEM manual states. The problem is there, cold or hot, so I don't think the coolant temp sensor is the problem. Crank and cam angle sensors test good when cold. I'm now leaning towards the coils, plug wires and igniters. Problem now is a lack of ridable test weather and salt to be on our roads soon her in NW PA.

User avatar
Rednaxs60
Posts: 1336
Joined: Wed Nov 18, 2015 12:44 pm
Location: Victoria, British Columbia, Canada
Motorcycle: 1985 GL1200 LTD, 2008 GL1800

Re: tps reading 1200 ltd

Post by Rednaxs60 » Tue Dec 05, 2017 6:16 pm

Here is some additional replacement parts info:
Replacement Parts

LX579 Sensors – used to replace the Gr/Gl sensors – good information – found these over on the CX500-650 turbo forum at:
http://cx500forum.com/forum/cx500-cx650 ... equal.html

PB Replacements - Type number: 100798-5630. Suzuki – P/N: 15620-35F00.
Suzuki description: Sensor Boost, IAP (Inlet Air Pressure) sensor. Have been using these on my bike for 4 months, working well. The PB sensors are only used by the ECU up to approximately 3000 RPM for engine operation. Up to approximately 3000 RPM for engine speed, the ECU uses TPS input, RPM and PB sensor info, after this it is RPM and TPS input.

Here is the correlation info between the Suzuki sensor and Honda OEM PB sensors:

Read in three columns:

Inches of Hg/Suzuki Sensor/OEM Sensor

0/3.45/3.63
5/3.1/3.14
10/2.65/2.59
15/2.18/2
20/1.73/1.43
25/1.26/0.88

Spark Igniter: These are obsolete. Have found new ones in the US from Procom Igniter set $79.00 USD. Here is web site: http://www.procomeng.com/estore/feature ... 900-a.html
Found this over on the CX500-650 turbo forum. Have had on line discussion on how to use for the my '85 LTD. Don't use the blue wire.

TPS replacement: using the BMI unit is good. Found a good used alternative – have 2 coming my way. These are from '85 Honda CRX. Same unit. Found this on the Red Pepper racing Forum.

I will eventually get to new coils and wires. Tried an aftermarket set and they failed within 2 months. Will be looking at the Accel or Dyna Coils 3.0 ohm units. Here is a forum site regarding the Accel coils: http://gl1200goldwings.com/gl1200/showt ... p?tid=9853 For the Dyna coils - a little bit of information on this forum thread: https://ngwclub.com/forum/viewtopic.php?f=1&t=58498

Also recommended to do plug wires and even plug caps.

Cheers
"When you write the story of your life, don't let anyone else hold the pen"

Ernest

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Rusty Bike
Posts: 340
Joined: Sun Feb 28, 2016 1:55 pm
Location: New castle, PA
Motorcycle: 86 GL1200 SEi, 98 Valkyrie Std, 78 Yamaha XS750SE, 86 Honda XL125, 4.5 HP belt drive Minibike my dad built, foot clutch!

Re: tps reading 1200 ltd

Post by Rusty Bike » Wed Dec 06, 2017 1:39 am

OEM coils and wires are available, pricy. Can use 97 Dodge Neon coil pac Delphi GN10142 or equ. Primary R is .7 ohms, also connector for same, Standard Motor Products HP3895. From Sanders GW site. You have to fab up copper core plug wires and build a bracket for the coil pac.
PB sensors, Toyota Denso 89420-02010, connector # DJ7036F-2.2-11/21 from CTX site
Coolant temp is available OEM. Possable sub from 85 Prelude, Beck/Arnley 1580156 and Airtex 5S1528 The intake air temp sensor my be the same item but OEM part #'s are one digit different.
I gota dig out those coils.

User avatar
Rusty Bike
Posts: 340
Joined: Sun Feb 28, 2016 1:55 pm
Location: New castle, PA
Motorcycle: 86 GL1200 SEi, 98 Valkyrie Std, 78 Yamaha XS750SE, 86 Honda XL125, 4.5 HP belt drive Minibike my dad built, foot clutch!

Re: tps reading 1200 ltd

Post by Rusty Bike » Wed Dec 06, 2017 2:14 am

I'll bet Finkeel is freekin out by now...LOL



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