ST1100 starving for fuel?

[RickA]

Steve and John,
Thanks for the quick responses (love these forums).

I didn’t even think about plugging the intake, I was going to remove the hose !!!

Anyway, Steve sounds like you have had this problem before. Did plugging the hose solve the problem?

I’m a bit afraid of the bike now, I need a reliable ride.

By the way, I’m going to Yuma tomorrow; guess I’ll be riding the Goldwing.

Rick

 

[RickA]

Well, I guess it’s not carb ice. It quit on the way home Thursday at about 70 degrees F. We made the last 40 miles of the trip on a tow truck. That was a total of 4 times that it quit in a 60-mile drive. So, now I need to duplicate this problem near home as I don’t plan on leaving town with it in this condition. I’m not 100 % sure that its fuel related but it sure feels that way.

Rick

 

[JMM_Illini]

I am not trying to hijack your thread, but my 1996 ST1100 w/ 55k miles has what sounds to be the exact same problem as you are experiencing. My commute is only 11 miles, but anytime after about 5 miles it starts to feel like it is running out of fuel. If I try to maintain road speed, the bike does eventually die and then won't always re-start right away. After a handful of minutes and repeated attempts to re-start the engine, it will start up and I can tak off again.

If I pull over before the engine dies, it will continue to idle fine and I can take off again at least for a while - usually for the rest of my fairly short commute. I first suspected the gas cap vent as well, so I ran for probably a month at the end of last summer with the cap loose but it did not seem to make a difference. I did not test the fuel pump to the extent you did, but it seems to run fine for the short time I did run it.

Today was my first commute of the season and it is doing the same thing even though I expected it to heal itself during winter storage. I need to replace spark plugs, fuel filter and air filter anyway, so I am going to try those first. Can the fuel cutoff be bypassed permanently, or is that a bad idea?

I am interested to hear your progress in fixing your problem. I will keep you posted on mine as well.

 

[John OoSTerhuis]

Rick. Coupla articles in the ST1100 Archive Of Wisdom (AOW) over at ST-Riders.net that may be of interest/help:

ST1100 AOW: Fuel Pump Diagnostics
ST1100 AOW: Fuel Cap Repair/Rebuild

Good luck and keep us poSTed.

John

 

[veefore]

I am not trying to hijack your thread, but my 1996 ST1100 w/ 55k miles has what sounds to be the exact same problem as you are experiencing. My commute is only 11 miles, but anytime after about 5 miles it starts to feel like it is running out of fuel. If I try to maintain road speed, the bike does eventually die and then won't always re-start right away. After a handful of minutes and repeated attempts to re-start the engine, it will start up and I can tak off again.

If I pull over before the engine dies, it will continue to idle fine and I can take off again at least for a while - usually for the rest of my fairly short commute. I first suspected the gas cap vent as well, so I ran for probably a month at the end of last summer with the cap loose but it did not seem to make a difference. I did not test the fuel pump to the extent you did, but it seems to run fine for the short time I did run it.

Today was my first commute of the season and it is doing the same thing even though I expected it to heal itself during winter storage. I need to replace spark plugs, fuel filter and air filter anyway, so I am going to try those first. Can the fuel cutoff be bypassed permanently, or is that a bad idea?

I am interested to hear your progress in fixing your problem. I will keep you posted on mine as well.

Take this for what it's worth but I found that the 95' that I had didn't like the Emgo aftermarket fuel filter I put on and immediately displayed exactly the same symptoms that you are describing as soon as I installed it. Ordered and installed an OEM fuel filter and the problem went away.

 

[EJ's 97ST]

Rick, haven't had a lot of time to read every post...gotta run lunch is up. My 97 had the same/same happen last year going to WeSTOC in Taos..... long story-short fuel cut-off relay. We by past the cut off wire with a rocker switch.....I've replaced the relay...no problem since.
EJ

 

[RickA]

John,
Thanks for the links, I did the fuel pump tests and my pump seems to pass with no problems. I also disassembled and re-built the fuel cap. I did find and clean out the orange-goo.

JMM, Take a look at the links John posted a few messages ago. Lots of good information there

EJ,
I plan on watching both sides of the fuel pump relay to help my troubleshooting.

My plan now is to “instrument” my bike with a couple of voltmeters and a fuel pressure gauge so that I can see what is going on with the fuel pressure and voltages when the problem occurs next time. I’m also going to remove the vacuum valve and replace it with a 2nd electric pump that I can switch on manually if the bike tries to strand me again

Intermittent faults are a real pain


I’ll keep you guys poSTed on my progress.

Rick

 

[John OoSTerhuis]

... I?m also going to remove the vacuum valve and replace it with a 2nd electric pump that I can switch on manually if the bike tries to strand me again ...

I believe John Parker and Dennis Sullivan added auxiliary fuel pumps to their ST1100s. I can dig around my archives and/or ask around if you're interested.

John

 

[RickA]

Yeah, John.
If you don't mind see what you can find. I had planned to add a Facet brand pump temporarily for just for troubleshooting. I didn’t plan on leaving it on there but I’m not too excited about being stranded again.

Thanks,
Rick

 

[firtree]

Have you removed the vacuum valve yet? Mine stranded me and my 1998 on
the side of the highway a few weeks ago. I have had no problems since I
removed the valve.

 

[JMM_Illini]

I just wanted to post an update on the fuel starvation issue on my '96 w/ 55k miles. I replaced the fuel filter with a Honda replacement (not Emgo) and I eliminated the vacuum shutoff valve. I rode about 40 miles yesterday and so far so good. I suspect it was the shutoff valve, but I still need to open it up to see check its condition.

Veefore - thanks for the tip on the Emgo filter.
Rick - thanks for pointing me toward the fuel pump diagnosis links.

I will post another update after some additional mileage.

 

[RickA]

Have you removed the vacuum valve yet? Mine stranded me and my 1998 on
the side of the highway a few weeks ago. I have had no problems since I
removed the valve.

No the vacuum valve was still in when I had the problem. It is out now (been replaced with a back-up fuel pump). I had rebuilt the valve last year with the kit from Ca. sport touring. I also tested the valve with a vucuum pump and it seemed to be working fine.

Rick

 

[JMM_Illini]

I just wanted to post an update to the fuel starvation issue my '96 ST1100 w/ 55K miles was having in case it helps anyone else. After removing the vacuum shutoff valve, I finally opened it up the other night and found that the diaphragm did indeed have a tear in it. My bike is working fine with the entire valve removed, so I do not plan to repair & reinstall the valve. Thanks to everyone for all the great information on this site that helped me figure out the source of my problem!

 

[veefore]

I just wanted to post an update to the fuel starvation issue my '96 ST1100 w/ 55K miles was having in case it helps anyone else. After removing the vacuum shutoff valve, I finally opened it up the other night and found that the diaphragm did indeed have a tear in it. My bike is working fine with the entire valve removed, so I do not plan to repair & reinstall the valve. Thanks to everyone for all the great information on this site that helped me figure out the source of my problem!

:clap2:!

 

[RickA]

Well, it looks like my problem is solved also. It was the fuel filter in my case. I had a tough time troubleshooting it but I learned a lot about the 1100 fuel system. I owe you guys a better write-up so I’ll do that under a new thread.

Rick

 

[John OoSTerhuis]

Well, it looks like my problem is solved also. It was the fuel filter in my case. I had a tough time troubleshooting it but I learned a lot about the 1100 fuel system. I owe you guys a better write-up so I?ll do that under a new thread.
Rick

Hi Rick,

Just noticed that you (might have) had it figured out a couple of weeks ago another thread.

I look forward to your write-up, you did a lot of diagnosing, even installed an aux pump... sure wondering just how 'new' your filter was, what kind of gas you've been using, and if the filter was an OEM or aftermarket(?)

Regards, John

 

[Bob Castiglione]

Not sure if this is the proper place to post But it is a fuel prblem and a fix to get you home
Bike had been sitting for three months
Changed handlebars and washed the bike.
Went for a test drive all was well for about 15 miles
Bike stalls (right under a street lamp blessings!!)
Can restart with full choke - no power
Can blow through the filter (ok I did suck on it first but I wanted to pull some fuel from the tank pttt!ptttt!)
Blew gas from the filter into the carbs - ran for a few seconds - Definately a fuel problem.
Bypassed the vacuum valve - no joy
Removed the vent frm the fuel cap
Cut the hose near the filler side of one of those 12 volt compressors, wire tied it onto the vent tube nipple on the gas cap.
Plugged the sae connecter to the on/off power supply for my heated jacket.
Turned the compressor on for about 5 seconds - pressurized the fuel tank fired it up and drove it home. happy man
There a certainly concerns about pressurizing the fuel tank, but theres also concerns about sleeping on the side of the road (was not going to leave the bike)
Question
With the fuel line removed from the input side shutoff valve and the ignition turned on I get no fuel flow or sounds of the fuel pump
I would like to meter power to the fuel pump and to the cut off relay.
I have a manual but we have recently moved and I have not been able to find it.
Is there a schematic available for a 1997 St1100 ABS available on the net and where is the fuel cut off relay located?
Thanks in advance for any help
Bob

 

[John OoSTerhuis]

Well, it looks like my problem is solved also. It was the fuel filter in my case. I had a tough time troubleshooting it but I learned a lot about the 1100 fuel system. I owe you guys a better write-up so I?ll do that under a new thread.
Rick

For those following along in this thread, here's Rick's new summary thread on his problem:
https://www.st-owners.com/forums/showthread.php?t=65394

 

[John OoSTerhuis]

Is there a schematic available for a 1997 St1100 ABS available on the net and where is the fuel cut off relay located?

Hi Bob. Pretty MacGyver of you, pressurizing the tank that way.

ST1100 colored wiring diagrams are here in my 'Misc Farkle/Maint/Mod Pics' Webshots album:
http://rides.webshots.com/album/90503268AADIOp

and here's a picture of the fuel cut off relay on a 91 standard (the one with the Stebel horn bracket behind it):


HTH

John

 

[Bob Castiglione]

Hi John
Thanks for the quick reply
I checked voltage on the two connectors on the tank that were not obviously ground (with the engine running)
One stayed low (I think for the fuel pump)
One went to 12 volts (I think fuel level)
I was not able to download the schematics The sight indicated I needed to be a "friend"
I saw your instructions to view full size and to download _ no luck
Any other directions would bw apprecated. Honda sure buried that relay did they!
Thanks again
Bob