Jump to content
NAGF News Ticker
  • New Feature!!!
  • The Tutorial Feature has Launched With Its First Tutorial...
  • "Using Classified Adverts"
  • Be Sure To Check It Out...
  • By Clicking On "Tutorials" In The Menu!!!
  • AND...
  • Watch For More Tutorials On The Way!
Sign in to follow this  
Galaxyhunter

1500 Fuel Pump

34 posts in this topic Last Reply

Recommended Posts

Galaxyhunter

This year, I have been having a small hesitation when leaving a stop sign, nothing major (like the '88 off idle problem), but just enough to no that something isn't up to snuff.  So today I changed my plugs & then went out of a trip around the block (5 miles or so) to warm up the engine so I can check / adjust the carb sync.  On the last leg of the ride, I had the cruise set @ 60mph & it started to spit & sputter losing speed.  As I got back into town it would hold the slower speed.

By the time I got it home, it would die if I didn't hold some throttle in it, & would die if I didn't have the choke level engaged a bit. I knew this was telling me of a fuel starvation problem.  So the first thing was to change the fuel filter.  After that I went to start it up.  After starting, it took a good 20-30 seconds for the gas to start trickling into the filter.  Now it barely runs with full choke.  If I twist the throttle at all, it  leans out & dies.

 

So this tells me that the fuel pump is taking a dump.  Does this sound about right, or is there something else that I need to look at?

  • Like 1

Share this post


Link to post
Share on other sites
dwsonar

You could look at the vacuum fuel shutoff, by the filler cap. If the diaphragm cracks and leaks, it may not be letting fuel pass. should be signs of leaking if it's bad.

Share this post


Link to post
Share on other sites
dwsonar

I don't think that's the real name for it

Share this post


Link to post
Share on other sites
pwhoever

dwsonar, you are talking about the auto fuel valve. If that is it, they do have rebuild kits instead of having to buy a whole new one. Wouldn't it also leak some fuel into the fuel tray if the diaphragm was split?

 

Carl, I posted on the other forum but how much fuel did you have when this happened? When mine went bad about 3 years ago, it would show up when the tank was under 1/2. Also it would show up when the weather was extremely hot, 90+.

Share this post


Link to post
Share on other sites
Galaxyhunter

I bypassed the petcock,  the filter is empty.  I started the engine & the only way to keep it running is full choke.  here is a link of the fuel filter that is not filling up.

http://hawkeye-observatory.com/GW/filter.wmv     Note:  this is a large HD file, so it might take a couple of minutes to load.

Share this post


Link to post
Share on other sites
pwhoever

If the pump is weak, it will give you very similar symptoms to a failed fuel pump and either requires a replacement. Do the fuel flow test but instead, use length of fuel hose so you can test with the jar up at head level. That will tell you if you have a weak fuel pump. A good pump should pump just as much to the raised jar as it would if the jar was held below the fuel tank. If it doesn't, your fuel pump is probably bad.

Share this post


Link to post
Share on other sites
dwlarson

I had a similar issue with my '96 Wing (1500) a few years ago.  It would start sputtering and sometimes just die (not a fun time at 12,000' in the Rocky Mountains).  With lots of choke I could finally get it going again.  This would happen may 1-2x a year (usually in very hot weather), then eventually every ride.

 

I replaced the fuel pump after lots of research, and no troubles ever since.  Some people have put in an auto pump (much cheaper) but I went with OEM replacement.  Look around online for a decent price -- it's expensive.  Also, and VERY IMPORTANT: replace the gasket that goes under the base.  The old one will leak once it's pulled apart; no sense not spending the extra $10 for all the trouble it is to get to the pump.

 

Good luck!

  • Like 1

Share this post


Link to post
Share on other sites
Bluthundr31

Is a silicon calk used between the tank and the gasket?

Share this post


Link to post
Share on other sites
Galaxyhunter

Is a silicon calk used between the tank and the gasket?

 

I didn't use any type of sealant.

Share this post


Link to post
Share on other sites
Bluthundr31

OK, thanks for the feedback. I picked up a new base gasket so it should be alright.

Share this post


Link to post
Share on other sites
Bluthundr31

Got a "used" OEM fuel pump off eBay from a bike that was running, (saw video of a bike running) for '88-'00 GL1500's. I installed the pump with 1/2-3/4 tank of good gas.  Bike won't start and I did not hear/feel the brief (2 sec.) fuel pump prime cycle.  WHAT CONTROLS THE FUEL PUMP PRIME CYCLE?   

Share this post


Link to post
Share on other sites
DaveO430

Not sure what year, I think 88-90 1500s had a fuel pump relay, after that it is controlled by the ECM and is a known failure, which is repairable. 

1500 ECU repair.pdf

Share this post


Link to post
Share on other sites
Bluthundr31

Thanks David, I might have to use that ".pdf" info but, when I disconnect the ECM and "jumper" the blk/blu wire to the blk/whi wire and get 10.5-11.9 volts at the "B" terminal of the fuel pump if I turn the key on, doesn't that indicate that the ECM is doing its job?  Its true that I do NOT hear the "prime" cycle of the fuel pump when I turn the key on, ,so is "no prime" indicative of the bad emitter as described in the PDF?

 

I took the fuel pump out and did a bench test;

1.)  completely submerged the fuel pump in a tub of gasoline with about 3" from the gasoline level to the base of the mounting plate for the fp.

 

2.)   Hooked up an "In-line" 5Amp ATO fused line using 12AWG wire from the +12 Volt side of a battery to the "B" terminal of the mounting plate for the fp.

 

3.)  Hooked up a 12AWG line from the -12Volt side of the battery to the "G" terminal of the mounting plate for the fp.

 

I GOT NO FLOW FROM THE FUEL PUMP.  I did notice that when the power was on, i saw a steady stream of "BB-sized" bubbles coming out of the cone shaped end of the pump near where the power wire is connected.  If i removed the power, the bubbles would slow down and eventually stop altogether.  Does the fuel pump need to be submerged completely to the base of the mounting plate?? I don't know where the bubbles are coming from unless the hoses are cracked/leaking.  

 

DOES THIS BENCH TEST SOUND EFFECTIVE TO ANY OF THE EXPERTS??  SHOULD I DO ANYTHING DIFFERENT?

Share this post


Link to post
Share on other sites
DaveO430

When you jumper those wires you are just bypassing the ECU, it doesn't indicate anything about it. Check if something is plugging the line out of the pump, if not you need a new pump. 

Share this post


Link to post
Share on other sites
Bluthundr31

I see what you're saying now. I've done so many dam tests on this problem I forget the correct response to your comment, , if I hook my voltmeter (+) to the "B" terminal and the (-) to the "G" terminal I get NO voltage when I turn the key on, but I get 10.5Volts when I hit the start button. Even though I get voltage, I get NO FLOW from pump. Could the lack of voltage when the key is turned on be the result of the condition you outline in that PDF file?

Share this post


Link to post
Share on other sites
DriverRider

As Dave wrote earlier only the 88&89 years had a fuel pump relay which would do a 2 sec. prime when key is first turned on. For all later years the fuel pump gets voltage direct from ECM with engine cranking or running only. If the pump is getting voltage and with no fuel flow then it is defective.

Share this post


Link to post
Share on other sites
Bluthundr31

Thanks guys, my '91 doesn't have a fuel pump relay so the 2 second "prime" doesn't apply, , , with voltage when cranking but no flow, the fuel pump is bad.  I hate that I might have wasted $$ on a "fishing weight" pump. . . . 

 

I'll get a replacement pump and let you all know how it goes., , , THANKS AGAIN

Share this post


Link to post
Share on other sites
DaveO430

 I hate that I might have wasted $$ on a "fishing weight" pump. . . . 

 

I'll get a replacement pump and let you all know how it goes., , , THANKS AGAIN

 

That is something you would never want to buy used, even if the seller says it's working. Free just to try it maybe but don't spend money on it. 

Share this post


Link to post
Share on other sites
Bluthundr31

Agreed, but luckily return policy is full refund (+ shipping) if the pump don't work. Sellers account gets a "hold" on it until the buyer, (me), gets the refund. (In THEORY that's how it's supposed to work). I'll let you know how it works.

Share this post


Link to post
Share on other sites
Bluthundr31

I might have "dodged-a-bullet" with the pump issue.  Seller made FULL REFUND (+shipping) within 24 hrs of receiving the return.  

 

Has the NAPA or the HFP option worked out for anyone here??  I'd prefer something that fits and "reasonably priced" that falls within the 2.5-3.5 psi and 10gph area.

Share this post


Link to post
Share on other sites
AZgl1800
Bluthundr31

Nice job John, ,Lots of good info there.

I took a minute or two to add that site as a resource for "how-to's" and pick the brains of some of the folks there. 

 

THANKS AGAIN, 

Share this post


Link to post
Share on other sites
DaveO430

Just to save you some more frustration, don't use an airtex pump. They have a terrible reputation. 

Share this post


Link to post
Share on other sites
Bluthundr31

Thanks David, I'll definitely steer clear of them,, , ,I got enough headaches without asking for more.  

 

John's setup looks to be the best I've found, , , I'll have to "re-read" it all to make sure I can understand and follow it.  (, , not always the brightest bulb in the marquis)

Share this post


Link to post
Share on other sites
Bluthundr31

Used the $$ from the eBay transaction to buy the Carter pump and strainer (with $$ left over!!)

 

Will let you know how the conversion goes?  THANKS AGAIN FOR ALL THE HELP/TIPS/INFO

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

×

Important Information

By using this site, you agree to our Terms of Use,