Need advice with possible fuel pump problem.

Need advice with possible fuel pump problem.
Bike is 1997 ST1100 ABS with 55k.
This weekend I rode to western NC, the tail of dragon area and rode 4 days with the Yamaha xs-11 rally, hard twisters, fast sweepers, and steep mountain roads.

The last day of the trip the bike lost power and acted like it was out of fuel, I kept it running by twisting the throttle and using the choke, but it died after ? mile. It had 210 miles on the tank and fuel gage said ? tank of fuel.
After a few minutes it restarted by using the choke, it ran rough for a mile then ran better, then died again after 5 miles and would not restart.

After getting the bike home (next day) the bike started.

Things I have done are:
1- Checked fuel cap vent and vent line-OK
2- Checked vacuum fuel shut-off valve-OK
3- Checked fuel filter-OK
4- Checked fuel pump fuel flow- 1150 ml per minute
5- Checked fuel pump amps- 1.37 amps
6- Checked fuel pump PSI- ? PSI maybe ? PSI (gage is hard to read that low) I can easily stop the flow with my finger.

Any ideas what the problem is?

To start with this "process of elimination" I would strongly suggest you remove the vacuum fuel shut-off valve. No special plumbing required. Once the Vacuum shut-off valve is removed, you'll see the fuel line going to the carbs will fit nicely onto the exposed end of the fuel filter. Vacuum petcocks are persnickety at best and down right abominable at worst. Get rid of it. This 5 minute task could solve your problem.

Also it sounds like a vacuum lock on the tank - we had a CB750 with that problem this past weekend. Full tank had enough pressure for gravity feed to work, but not when it got low. Yours might have built up enough vacuum to work against the pump. The cap has a spring loaded valve - maybe shooting some carb cleaner through from top and bottom might help.

When my pump failed it was due to low fuel that will allow the OEM pump to get too warm and seize, but only till it cooled down. Running a full-ish tank cured it till I got the aux. pump in.
I removed the Vac. shut off and plumbed the Facet in line where it was. Never starved again.

As was said, remove the cut off first and see if it fixes the problem. Next suspect would be the fuel pump - they will work, then quit, then work, etc. especially as Mark noted when they get 'warm'. Or it could be the fuel pump relay starting to flake out. Lots of options for replacing them in many threads on this board. Having got caught out on a long trip with this problem, I now carry a 'kit' prewired with hoses, clamps and a pump just in case it happens again. Pretty cheap insurance - especially if you are stuck out in the middle of nowhere.

Things I have done to trouble shoot my problem:

1- Removed the little red washer/check valve from the fuel cap.
2- Cleared fuel cap vent line.
3- Removed vacuum fuel shut-off valve
4- Replaced fuel filter
5- Checked fuel pump fuel flow- 1150 ml per minute
6- Checked fuel pump amps- 1.37 amps
7- Checked fuel pump PSI- ? PSI maybe ? PSI (gage is hard to read that low) I can easily stop the flow with my finger.
8- Filled fuel tank with fuel.

Took it on 50 mile test drive every thing OK, I don’t know what caused the problem but it runs OK now. I plan on getting an aux. fuel pump in case it happens again.

I was just reading somewhere that someone's woes were due to a fuel filter that didn't flow enough. maybe that was it as you just replaced it.

Get a low pressure car fuel pump 86-89 carbureted Honda accord fuel pump works well. My bike could not be more exactly like the symptoms you experienced. Fuel pump gets hot and it cuts out. Easy to start the next morning after completely cooling. I just went on a 450 mile trip this last weekend and no problem with the new delphi pump I got from rockauto.com

Thanks, Advance Auto wanted $55.00 rockauto was $16.00

Saltydog said:

Thanks, Advance Auto wanted $55.00 rockauto was $16.00

Click to expand...

Part # or name?

DeanR said:

Part # or name?

Click to expand...

Go to
http://rockauto.com/
Select;
Honda, 1986, Accord, 2.0L L4, Fuel/Air, Fuel Pump, Performance Electric P06k looks like the correct pump, but I need to get more info before buying.

Saltydog said:

Go to
http://rockauto.com/
Select;
Honda, 1986, Accord, 2.0L L4, Fuel/Air, Fuel Pump, Performance Electric P06k looks like the correct pump, but I need to get more info before buying.

Click to expand...

http://www.rockauto.com/catalog/moreinfo.php?pk=1400485&cc=1166835&jnid=409&jpid=1

Edit: isn't this Airtex E8371, 2-4 psi pump a little further down the page what some folks have used?
http://www.rockauto.com/catalog/moreinfo.php?pk=60039&cc=1166835&jnid=409&jpid=17

John

Was asking about the exact part number because I had the exact experience a couple days ago for the first time, after having read about this problem frequently over the years.
Bike got running rough, then no throttle response, slower, slower and then conked out.
I waited a few minutes, opened the fuel cap, and it started with choke. Back on the road.

John OoSTerhuis said:

http://www.rockauto.com/catalog/moreinfo.php?pk=1400485&cc=1166835&jnid=409&jpid=1

Edit: isn't this Airtex E8371, 2-4 psi pump a little further down the page what some folks have used?
http://www.rockauto.com/catalog/moreinfo.php?pk=60039&cc=1166835&jnid=409&jpid=17

John

Click to expand...

Yes - I'm one of those that is running the Airtex. I'm on my 2nd one - the first one appears to have been the cause of my intermittent fuel delivery issues that had me chasing my tail for over a year as documented on this thread:

https://www.st-owners.com/forums/showthread.php?122782-Engine-quit-request-for-diagnosis-assistance&highlight=

I finally just went ahead and replaced it over the winter and gambled on replacing it with the same thing. The only thing I've done differently was I hacked the regulator out of the OEM pump and plumbed it inline with the Airtex as I mention in post 94 of the thread above. So far so good - have run my bike in a wide variety of conditions all year this year including 2400 miles over 4 days this past weekend as I participated in the VOID rally and have had no issues.

LibertyDeath76 said:

Get a low pressure car fuel pump 86-89 carbureted Honda accord fuel pump works well. My bike could not be more exactly like the symptoms you experienced. Fuel pump gets hot and it cuts out. Easy to start the next morning after completely cooling. I just went on a 450 mile trip this last weekend and no problem with the new delphi pump I got from rockauto.com

Click to expand...

+1 on the Delphi pump. The local auto repair shop won't use anything except Delphi pumps. And my auto parts store says they have had a lot of problems with Airtex pumps. I installed a Delphi in my '98 ST1100 a few years back , as a PM measure. I got mine from Rock Auto also. In fact, I bought two. The other is stored in my top case. Maybe some day I will run into a fellow ST1100 Rider stranded on the side of the road ........

Jim Van said:

+1 on the Delphi pump. The local auto repair shop won't use anything except Delphi pumps. And my auto parts store says they have had a lot of problems with Airtex pumps. I installed a Delphi in my '98 ST1100 a few years back , as a PM measure. I got mine from Rock Auto also. In fact, I bought two. The other is stored in my top case. Maybe some day I will run into a fellow ST1100 Rider stranded on the side of the road ........

​

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Yes, that's the same pump however I mounted mine horizontally in the factory bracket and have had no problems. Put in 6.9 gallons on yesterdays fill up after running for 2 days with the gas light on. Just turn the pump so the pickup on the pump is towards the bottom. I did have to buy 1 ft of fuel line as the factory hose is not quite long enough.

Which Delphi pump, Jim? TIA

John

LibertyDeath76 said:

Yes, that's the same pump however I mounted mine horizontally in the factory bracket and have had no problems. Put in 6.9 gallons on yesterdays fill up after running for 2 days with the gas light on. Just turn the pump so the pickup on the pump is towards the bottom. I did have to buy 1 ft of fuel line as the factory hose is not quite long enough.

Click to expand...

I hope you used fuel hose that can be submerged in fuel. On a old post, some one had a fuel hose blow out in the tank.

I re-used the existing hoses on mine. the airtex has been in there for more miles than the OEM pump now - I did add a fuel pressure regulator because without it it was running way rich - no choke required in the morning, and fuel consumption went from 42 to 32mpg.
Eventually, when I find the time I plan to re-use the pressure regulator from the OEM pump so I can get rid of the external one I'm using now.

Woonjas said:

I re-used the existing hoses on mine. the airtex has been in there for more miles than the OEM pump now - I did add a fuel pressure regulator because without it it was running way rich - no choke required in the morning, and fuel consumption went from 42 to 32mpg.
Eventually, when I find the time I plan to re-use the pressure regulator from the OEM pump so I can get rid of the external one I'm using now.

Click to expand...

Was the pump you installed a low pressure pump ( for a car with a small displacement engine and using a carburetor ) or a high pressure pump ( for a car with fuel injection ) ? What was the Airtex part number ? i'm just surprised you had a problem without the addition of the pressure regulator. So what is the output pressure of the pressure regulator ?

Just curious ......