Jump to content

Due to a hardware failure on the hosts systems, all posts and messages created between May 26th and Jan 13th have been lost. Additionally, if you joined the NPORA Forums community during that time, you'll need to re-register. -NPORA Mod Team *Updated: 05/19/2022 12:15AM PST

Fuel Disaster


djratlif
 Share

Recommended Posts

Figured I should add something to the forums after taking so much from here recently. Yesterday I was leaving my driveway and the engine just stalled out like it was out of fuel. Suspecting that I was out of gas I filled it up and started it again. Life was good... for a mile or so. After waiting a few minutes I could restart the motor and drove it back as quick as I could. After looking under the hood this morning and doing a few tests I found that the fuel pressure would be 36 psi for a bit, but if it ran a while longer the pressure would suddenly drop and kill the engine.

 

After lifting up the carpet and removing the cover (which was missing three of the four bolts), this is the beautiful sight I laid my eyes on.

5baf2122-771e-4d70-919c-045d8d3e9588_zps

 

It looks like one of the previous owners was a serious redneck when it came to fixing things.

 

20131018124413_zpseb797a78.jpg

 

This is what it looks like under all of the silicone/hot glue mess that was there. Looking at all the wiring and not seeing a good way to fix the existing setup I went about drilling out the bottom of the studs and removing the oem wiring attachment points.

 

20131018124424_zpsb77c8802.jpg

 

This is where I was drilling to remove the studs on the inner side of the sending unit. After removing the stock attachment points I was left with rather large holes for the wires to slide through. To make a tight fitting seal I used some extra vacuum hose I had laying around to go around the wire like a rubber grommet.

 

20131018140559_zpsd6c9fee1.jpg

 

That is the outside view.

 

20131018140618_zpsac5397ee.jpg

 

This is the new inside view before I replace the pump and strainer. I plan on soldering the connections and shrink wrapping them so I don't have any problems later on. Also chopped off the unprotected butt connectors in the first picture as well. They wouldn't last long when I sink this in a mud hole later on. I'll keep updating as I get more done. The pump won't be in until early next week so if anyone has any better ideas I would gladly accept some input and change the design up to work better.

Link to comment
Share on other sites

As an electrician I have an overwhelming desire to smack the po of your truck :lol: Anyways Excellent find! This is a nightmare waiting to happen especially if I connection came loose and shorted out causing an ark, bad news near your gas tank.

Edited by cvdloc
Link to comment
Share on other sites

What a hack job! I hate fixing other people's rigged fixes. Luckily for me the PO of mine replaced the entire sending unit with a new one from nissan, So hopefully I won't have to worry about that for a while.

 

Also I would change out that worm gear hose clamp for a proper fuel injection one.

Link to comment
Share on other sites

The worm one is standard Nissan and it doesn't hold a lot of pressure because it's only the return line. The feed line does have a proper clamp.

 

I have a theory that Nissan does this to label the hoses so the return and feed lines never get installed backwards.

 

Edited by Tungsten
  • Like 1
Link to comment
Share on other sites

  • 4 months later...

Figured I should add something to the forums after taking so much from here recently. Yesterday I was leaving my driveway and the engine just stalled out like it was out of fuel. Suspecting that I was out of gas I filled it up and started it again. Life was good... for a mile or so. After waiting a few minutes I could restart the motor and drove it back as quick as I could. After looking under the hood this morning and doing a few tests I found that the fuel pressure would be 36 psi for a bit, but if it ran a while longer the pressure would suddenly drop and kill the engine.

 

After lifting up the carpet and removing the cover (which was missing three of the four bolts), this is the beautiful sight I laid my eyes on.

5baf2122-771e-4d70-919c-045d8d3e9588_zps

 

It looks like one of the previous owners was a serious redneck when it came to fixing things.

 

20131018124413_zpseb797a78.jpg

 

This is what it looks like under all of the silicone/hot glue mess that was there. Looking at all the wiring and not seeing a good way to fix the existing setup I went about drilling out the bottom of the studs and removing the oem wiring attachment points.

 

20131018124424_zpsb77c8802.jpg

 

This is where I was drilling to remove the studs on the inner side of the sending unit. After removing the stock attachment points I was left with rather large holes for the wires to slide through. To make a tight fitting seal I used some extra vacuum hose I had laying around to go around the wire like a rubber grommet.

 

20131018140559_zpsd6c9fee1.jpg

 

That is the outside view.

 

20131018140618_zpsac5397ee.jpg

 

This is the new inside view before I replace the pump and strainer. I plan on soldering the connections and shrink wrapping them so I don't have any problems later on. Also chopped off the unprotected butt connectors in the first picture as well. They wouldn't last long when I sink this in a mud hole later on. I'll keep updating as I get more done. The pump won't be in until early next week so if anyone has any better ideas I would gladly accept some input and change the design up to work better

 

Had a broken power wire. Did this today. Just saved me $173 Thanks for the write up

 

Link to comment
Share on other sites

As a retired Nissan Mech/tech I don;t remember ever seeing the worm screw clamps on any factory hoses, it was always the type of clamp that was on the upper hose. On the larger hoses it was the wire type with the screw and the tab that was tapped to the screw threads

Link to comment
Share on other sites

It's not clear to me where the black ground wire is connected. From the second picture it appears black is connected to blue/red on the 2nd post from the fuel rail? From the 3rd pic, this would appear to match where the large black wire on the underside is connected. Can you confirm this is how they are connected? I've got 5 wires, and 4 posts, with the black ground wire having had it's connector rot away so it's just dangling.

I'm pretty sure I'm about to have to complete this repair, as my fuel sender looks to be in similar condition, heavily corroded.

Link to comment
Share on other sites

the black was originally connected to the short blue/red stripe wire. When I got done it connected straight to the ground wire from the pump. A word of advise if you do plan on rebuilding it, use PTFE coated wire if I remember correctly. The gas will eat most wire insulators from what I've heard, and bare wires in the tank are a no-no.

Link to comment
Share on other sites

Found a clear picture of all the wires attached like stock here: http://www.nissanpathfinders.net/forum/topic/28592-fuel-senderpump-unit-switched-out-1993-wd-21-pathfinder/

Mine is dangling, looks like it needs to be soldered back onto the top itself, next to the 4 prongs. FYI, having that bad ground likely led to the unit being over-amp'd and burning itself up from what I'm reading on other fuel pump related threads. I can tell you mine was making the 15A fuse I used to get home so hot I couldn't hold it after pulling it out when I got it home.

Link to comment
Share on other sites

** IMPORTANT FIRE HAZARD WARNING **
Until looking at the fuel sender I would have never given it a second though. The connector was so severely corroded it had come loose from it's linkage (a kind of rivet connection) and the plastic housing had completely broken off leaving it free to spin, loosely connected.. When I pulled back the carpet and removed the top and had the gf turn the key to see if I could hear the pump, it immediately became so hot the plastic on the wire began to melt and smoke. Only after removing all power and removing the sender unit and the pump did I realize that the exact same thing was happening on the INSIDE connector, INSIDE my fuel tank filled with nearly 20 gallons of gasoline. Melted connectors, melted plastic on the wire, and the plastic backing for the plate the internal wire was connected to had very nearly completely melted. I can only imagine what would have happened had I continued to crank the key in desperate hopes it would start, say, in the gas station lot it stalled on me in, had I not identified the problem when I did..

Phew. Ok. I just performed this repair on my sender unit, only I just did the primary power wire which was severely corroded and loose fitting which very nearly started a fire which was only realized after removing the entire fuel assembly. I popped the connector and ran the primary power wire through the cap, then soldered/heat shrunk the connection to newly spliced in wiring. Also re-attached the ground wire to the plate with a screw and siliconed the connections.

 

In hindsight, and thinking about how to make this design better for the remaining connections, as well as shore up the quick repair job i just did, I am considering adding eyelets to each internal wire, and passing a bolt through from the inside to the outside using a plastic standoff and washers to insulate the bolt from the sender cap itself, filling the gap w/ gasoline safe sealant or epoxy. Place another plastic washer and a nut on the end of the bolt to secure it to the fuel sender cap and lock the internal wiring in place. Adding a lock nut on top of that to secure it and epoxy/tack weld it. That would leave 4 posts on top of the sending rail, one each wire from the harness. One could then use nice ring connectors and make a new wiring harness out of much more heavy duty materials. Each stud would be well insulated from the metal sending unit cap, and from each other, and would result in a much more heavy duty and serviceable unit than factory. One could pass another bolt through for the ground next to the 4 power wires..

 

There's a '94 at the pick n pull I was going to go salvage a new unit from, perhaps i'll grab it and use it as a testbed for the above design.

This would provide 4 heavy duty posts to connect some fresh wiring. Regarding the wiring from the harness to the pump, the entire length of it was corroded. Will be popping each connection out and running brand new 16ga wire from the connector to the pump after i'm done.

Edited by madhakish
Link to comment
Share on other sites

Mods:
Might not be a bad idea to sticky a post with this information. I'll make sure to post some pictures of both the damage I saw and the repair performed, but at the very least I would hate to see someone (or someone's pathy) burn up because a wire corroded inside their fuel tank which led to a failure of the insulation and a spark.

 

** IMPORTANT FIRE HAZARD WARNING **
Until looking at the fuel sender I would have never given it a second though. The connector was so severely corroded it had come loose from it's linkage (a kind of rivet connection) and the plastic housing had completely broken off leaving it free to spin, loosely connected.. When I pulled back the carpet and removed the top and had the gf turn the key to see if I could hear the pump, it immediately became so hot the plastic on the wire began to melt and smoke. Only after removing all power and removing the sender unit and the pump did I realize that the exact same thing was happening on the INSIDE connector, INSIDE my fuel tank filled with nearly 20 gallons of gasoline. Melted connectors, melted plastic on the wire, and the plastic backing for the plate the internal wire was connected to had very nearly completely melted. I can only imagine what would have happened had I continued to crank the key in desperate hopes it would start, say, in the gas station lot it stalled on me in, had I not identified the problem when I did..

 

Link to comment
Share on other sites

the black was originally connected to the short blue/red stripe wire. When I got done it connected straight to the ground wire from the pump. A word of advise if you do plan on rebuilding it, use PTFE coated wire if I remember correctly. The gas will eat most wire insulators from what I've heard, and bare wires in the tank are a no-no.

 

May want to double check the grounding. The ground wire from the pump appears to be attached to the blue/red connector internally, but the external ground wiring is connected directly to the top of the fuel sending unit as noted in one of the pictures in the forum post I linked to.

 

Anywho - until I can procure some ptfe coated wire, or execute the fix I just posted, I've run the primary power wire out the hole and made the connection external from the sender unit, sealing the hole w/ gas safe sealant.

Link to comment
Share on other sites

Mods:

Might not be a bad idea to sticky a post with this information. I'll make sure to post some pictures of both the damage I saw and the repair performed, but at the very least I would hate to see someone (or someone's pathy) burn up because a wire corroded inside their fuel tank which led to a failure of the insulation and a spark.

 

 

Agreed. If you could please add some pictures, we'll make sure this is properly posted.

 

B

Link to comment
Share on other sites

Pics will have to wait until I can get some gas out of the tank and have a bit more free time.. Moving in a week so things are largely packed up ATM. This was a quick fix out of necessity so it's not what I want it to be as I don't have access to all my normal tools and work space, but it's sturdy, and most importantly safe and functional for the time being. Should have taken some during the process but I was crunched for time and didn't think to document the process. Until then I'll try to diagram it and take a few pics from the top as it exists now.. I think I'm going to go with the 5 bolt plan leaving a standoff for each wire making it easier to fix the wiring harness at the same time. My wiring was corroded nearly back to the plug..

 

 

Sent from my iPad using Tapatalk

Link to comment
Share on other sites

Picked up the hardware for mounting new standoffs.

5x 1.5"L 1/8"W machine screws
5x 1/2"W nylon standoffs - tight fit to the screws above

15x hex 1/8" hex nuts

 

Each screw will use 3 nuts to hold the assembly together.

I'll drill out each connector to the diameter of the nylon and epoxy that in place, and crimp/solder ring connectors to the internal wiring and screw each ring connector down using the first nut. Then pass each screw through the nylon standoff, mounting it with yet another nut and epoxy the whole thing together from the top w/ gasoline safe silicone on the underside of the cap.. Because this is the internal connection for the sender it won't be serviceable so we don't care about the bolt being permanently affixed to the fuel sender. Once the epoxy is dry I'll have 5 standoff's approx 1/4" in length protruding from the fuel sender cap and one hex nut for each standoff. Ring connectors on each wire from the factory harness and another hex nut will complete the job. Hopefully I can get this taken care of this weekend.

Link to comment
Share on other sites

As I had a post a while ago about fuel pumps and so have others, I'm glad everyone has a fire extinguisher ready.

 

Justin Case.

  • Like 1
Link to comment
Share on other sites

As I had a post a while ago about fuel pumps and so have others, I'm glad everyone has a fire extinguisher ready.

 

Justin Case.

That and the resistor packs by the squirrel cage!! :)

 

Though, if that thing did go up with my face hovering over it, it probably wouldn't have much mattered at that point.

Link to comment
Share on other sites

Just to update, I have been driving this daily since the repair was made without an issue. I have not swamped it in water or mud yet, just a bunch of snow/salt/sand/water mixture.

  • Like 1
Link to comment
Share on other sites

  • 7 months later...

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
 Share

Welcome to NPORA Forums

 

Please register to gain full access to the forum.

Make sure you read the Forum Guidelines and don't forget to post a new intro in the New People Start Here! section, to say hi too everyone.

 

-NPORA

×
×
  • Create New...