Quantcast
Jump to content

Jacksnife

Fuel pump (circuit) problem

Recommended Posts

When I start the motor it kicks in the pump, pressures up and starts every time. But after a while at idle it will start to cycle power to the pump.... then finally no power to the pump at all and dies. Pump works fine hooked straight to battery.

So I have some kind of electrical issue. I cleaned the contacts on the fuse and relay... even swapped them with the fan's, no help. Now I'm thinking there is some kind of oil pressure switch inline with the fuel pump but I can't follow the wiring diagrams very well. Has anyone worked on this circuit?

PS. I replaced the fuel pump with a Premium 5211007 (autozone) and it works fine on straight battery power. It fits better than the Bosch too because it's fatter and comes with hard rubber surround. I changed the line from the filter to the pump to 3/8 too.

Share this post


Link to post
Share on other sites


Oops! never mind... it is crapping out even with the fuel pump directly connected to a battery. When the pressure starts dropping I can pinch the output hose of the pump... then it'll get a burst of fuel and fill back up again. It's acting like it's not getting fuel to the pump... or maybe not enough fuel and getting too hot? I'll go run it into a gas can until the tank is empty to see if it has good constant flow.

Share this post


Link to post
Share on other sites

Pumped a whole tank out no problems... cool as a cucumber. Next I hooked up the regulator to see if I could get a tank through it... nothing coming out of the regulator at all!! so I think I was overheating my pump is all. I don't think I'll find one that mounts like this one, so I'll first try taking it apart :) haha

Share this post


Link to post
Share on other sites

Easy enough! problem solved. The regulator is just like any spring loaded regulator. Cleaned it up and it's ok now. I have it set at 60lbs and it runs fine... but I think I remember reading 73lbs?

Share this post


Link to post
Share on other sites

Found it on pg 53 in the 2009 manual

Fuel pressure adjustment Never make unnecessary adjustments. The factory recommended settings are correct for most applications. The recommend fuel pressure is 3.5kgf/m2 (49.8 psi). It’s not necessary to adjust fuel pressure unless the fuel pressure really needs to be adjusted. To adjust the fuel pressure: 1. Loose the lock-nut with a 14mm spanner as the following picture. 2. Turn the adjustment-bolt clockwise with a inner hexagon spanner to increase the fuel pressure, and counterclockwise to decrease the fuel pressure. 3. Keeping one eye on the fuel pressure indicator while turn the adjustment-bolt, when the indicator shows about 3.5kgf/m2 (49.8 psi), stop turning, and tighten the lock-nut.

Until it shows "about 49.8psi" haha

Share this post


Link to post
Share on other sites


I got it as close to 49.8 as I could : )

It still doesn't run perfect yet though. It sputters sometimes at full throttle and feels like it loads up at crawling throttle. It is new to me and I had to start with a complete overhaul, so I don't know how many other problems I need to deal with... but it feels like some sensors are AFU. The motor was smoking like a chimney when I got it, and by the looks of the motor internals they ran it like that a loooong time. I'm guessing the O2 sensors are trash? I wish I could hook up something to read the computer. There must be a way, I'll study that today.

Share this post


Link to post
Share on other sites

I don't know of anyway to read the computer I know no limits Powersports had something and silver bullet motor sports did maybe McCoy motor sports too or a wide band AF??

Share this post


Link to post
Share on other sites

I run 35 PSI on my regulator, Hook a light across your fuel pump to monitor the voltage,

also, on the computer pin out. X1-70 - MIL - Mal-function Indicating Lamp Output could be hooked up to show if you actually have a malfunction. If you want to do that, just remember that pin X1-70 is a sink to ground, that means that 12 volts is supplied to a light and the light is grounded via X1-70 if there is a mal-function.

Share this post


Link to post
Share on other sites

It ran pretty good yesterday, no stuttering or sputtering just good clean acceleration. It was running much cooler than normal too. It's getting happier with its new home : )

  • Like 1

Share this post


Link to post
Share on other sites


Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Similar Topics

    • By Regretting my choices
      Hello.  I purchased this unit as a "non runner" with the intent of using the frame to build a go-cart, but once I got it home it seemed way to good to part out.  The motor cranks over, and I have spark, but no fuel.  If I put a little fuel in the cylinder it fires up until that fuel is burnt, then of course it dies.  The fuel pump is not running and I have removed the plug and there is no power going to it.  I have checked the safety switch on the brake pedal and its fine, I have checked the fuses, all good, but am not sure where to go from here. The shifter is missing on the unit, but the indicator light on the dash shows its in neutral, and the e-brake indicator switch is working as well.  I am thinking of jumping power to the fuel pump next to see if it runs and if the motor will start.
      What am I missing?  What can stop the fuel pump from getting power to it?
       
       
    • By Hisunsadman
      Last October we were sitting at an idle on a Sunday morning and it died for the first time since we time since we bought it new I've already sent it to the shop because it's under warranty after trying to fix it. New fuel injector new spark plug couldn't do a compression check because I couldn't find anything to fit it but now that it's at the shop I have a feeling that the exhaust valves tighten themselves up and they are not closing anybody ever have this problem?
    • By Travis
      It''s sleeting here now, though the radar just shows rain, looks like the rest of Texas is going to get snow too. it's 37° right now.
    • By Sledge
      I have a 2016 cub cadet challenger 750. In the past month it has started to lose power at about 25 mph, sounds like it is struggling for fuel. Any suggestions?
    • By McMURDY
      Just joined this forum. I am a new owner of a used 2016 Cub Cadet Challenger 750 Crew. I bought it from a friend's wife after my friend suddenly passed away this Summer. We hadn't run it much since when he passed in July and I used it to do some light plowing on my driveway last month and a handful of times during hunting season. Then, we got blasted with bitter cold and 2 feet of snow last week and it wouldn't start. I assumed the battery was low (from JUN 2018) and put another lawn and garden battery on I had which was relatively new and unused. It runs a plow and a front and rear LED light too. It started right up with the new battery, but when my wife plowed with it for 10-15 minutes, it ran dead. It has 250 CCA (the previous one had 350 CCA). Not knowing any better, I jumped it with my car running and let that charge it for 1/2 hour but got the same thing....a few swipes with the plow and it was dead again. I left it on the charger overnight, hoping that will give it a full charge and that will take care of the problem but I don't want to find out it doesn't work when another storm comes. Should I get a new battery? What do you guys recommend that will run the motor, the plow and the extra lights and do you charge it often during cold weather? Wish my friend was around to ask him what he did but he's gone and I'm new at this.  Thanks!


×
×
  • Create New...