Fuel filler tube ground strap


Tsandershsa

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Yesterday started out like any other day… went to father in laws to check on him and when I came back out the jeep cranked but didn’t start….hmmmmm…. Pulled a code p0320, cps…. That’ll cause it so I hopped in his truck and I go to adanced auto and get 1…. $71, WTF…. Go back to his house and of course it’s the wrong one, I know better than to go to a parts house blind with a 97 TJ, seems they used several different year parts to build… got money back and after 3 parts houses I found that auto zone had one at their location 15 miles away, so off we went… $105, WTF…. Get back home and plug it in, crank no start, I should have checked for spark before I left the first time but the cps code made me feel invincible, so I pulled a plug wire off the plug and of course left the metal end on the plug so I had to fix that… check for spark and I’ve got spark (probably had spark before I changed the cps),,, sprayed starter fluid into the manifold and it attempts to start, fuel issue, darkness falls… so today (after a night of reading till my eyes bleed) I’ve got to see it I have fuel pressure (no Schrader valve), check the relays, check the fuses, and look for anything wrong with the wiring to the fuel pump… of course I filled it full of gas 2 miles before I got to my father in laws house!…. I Love my jeep!

*update*…. All fuses and relays good, fixin to call a tow truck when father in law says sometimes hitting the gas tank with hammer may get it working… while under the tank I see this thin braided silver wire hanging… ground wire came loose… regrounded and drove it home… I love my jeep!

so this grounding strap goes to the filler neck… I’ve read several posts saying this is more a safety thing then anything… if this wire is broke free should it cause a fuel delivery problem?
 

TJ4Jim

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Yesterday started out like any other day… went to father in laws to check on him and when I came back out the jeep cranked but didn’t start….hmmmmm…. Pulled a code p0320, cps…. That’ll cause it so I hopped in his truck and I go to adanced auto and get 1…. $71, WTF…. Go back to his house and of course it’s the wrong one, I know better than to go to a parts house blind with a 97 TJ, seems they used several different year parts to build… got money back and after 3 parts houses I found that auto zone had one at their location 15 miles away, so off we went… $105, WTF…. Get back home and plug it in, crank no start, I should have checked for spark before I left the first time but the cps code made me feel invincible, so I pulled a plug wire off the plug and of course left the metal end on the plug so I had to fix that… check for spark and I’ve got spark (probably had spark before I changed the cps),,, sprayed starter fluid into the manifold and it attempts to start, fuel issue, darkness falls… so today (after a night of reading till my eyes bleed) I’ve got to see it I have fuel pressure (no Schrader valve), check the relays, check the fuses, and look for anything wrong with the wiring to the fuel pump… of course I filled it full of gas 2 miles before I got to my father in laws house!…. I Love my jeep!

*update*…. All fuses and relays good, fixin to call a tow truck when father in law says sometimes hitting the gas tank with hammer may get it working… while under the tank I see this thin braided silver wire hanging… ground wire came loose… regrounded and drove it home… I love my jeep!

so this grounding strap goes to the filler neck… I’ve read several posts saying this is more a safety thing then anything… if this wire is broke free should it cause a fuel delivery problem?
The ground or lack thereof will not cause any fuel issues as the pump has it's own ground in the connector. It can be replaced with a stranded wire of similar size without issue.

You will find that most aftermarket Crank sensors are total crap so stick with NTK which is the original Mopar supplier or in a pinch the NAPA Echlin's are an alternative.

If you have spark and she tries to start with fluid then the fuel pump is a good culprit.
 
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Tsandershsa

Tsandershsa

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So I clipped it to the body and it started… took it back off and it wouldn’t start.. clipped it back to the body and drove it home… have I got another problem?
 

TJ4Jim

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There’s got to be a failing ground somewhere
Disconnect the fuel pump connector just forward of the driver side rear tire and inspect the body side connector, there will be 3 contacts, pump power-ground-level sensor. check the black for ground and follow forward looking for any damage.
 
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Tsandershsa

Tsandershsa

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So I looked at the fuel pump connector and found that the clip was broke off so I taped it together and traced the wiring till it ran up over the transmission and didn’t find a damage… jeep ran fine for a day or two and then on a rough road it just suddenly died, I was able to restart it but it sounded like it was running out of gas, sputtering, and then it died again…I got under it and shook the fuel pump plug and it started right up and ran like there was no problem… so I figured got to be fuel pump, 24 years old, broken clip, it’s time for a new one… dropped the tank and replaced the filter (it was the original) and put everything back together and went to start it it would crank but not start… I could hear the fuel pump prime and I would cycle it 10 times several times and it would try to start but no glory… finally I sprayed starter fluid in the intake and it started right up but would die when it was gone… so i thought maybe clogged fuel line so I disconnected the fuel line at the rail (no schrader valve) and tried to start it and it shot gas across the engine bay… connected the line back to the fuel rail and tried to start, no start!… by this time I’m stumped so I call my FIL and explain the steps I’ve gone through and show him (facetime) how much starter fluid I put in for it to start, turn the engine over, and the son of a bitch starts!!! went out this morning and it starts first try and I connected the old fuel pump to 12 volts and it works…. I’m a little nervous about Trusting it until I figure out what caused the issues… any ideas?
@Jerry Bransford

Todd
 
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TJ4Jim

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So I looked at the fuel pump connector and found that the clip was broke off so I taped it together and traced the wiring till it ran up over the transmission and didn’t find a damage… jeep ran fine for a day or two and then on a rough road it just suddenly died, I was able to restart it but it sounded like it was running out of gas, sputtering, and then it died again…I got under it and shook the fuel pump plug and it started right up and ran like there was no problem… so I figured got to be fuel pump, 24 years old, broken clip, it’s time for a new one… dropped the tank and replaced the filter (it was the original) and put everything back together and went to start it it would crank but not start… I could hear the fuel pump prime and I would cycle it 10 times several times and it would try to start but no glory… finally I sprayed starter fluid in the intake and it started right up but would die when it was gone… so i thought maybe clogged fuel line so I disconnected the fuel line at the rail (no schrader valve) and tried to start it and it shot gas across the engine bay… connected the line back to the fuel rail and tried to start, no start!… by this time I’m stumped so I call my FIL and explain the steps I’ve gone through and show him (facetime) how much starter fluid I put in for it to start, turn the engine over, and the son of a bitch starts!!! went out this morning and it starts first try and I connected the old fuel pump to 12 volts and it works…. I’m a little nervous about Trusting it until I figure out what caused the issues… any ideas?
@Jerry Bransford

Todd
A condition you describe could easily be a damaged or corroded wire in the pump harness on the Jeep side. Had a similar intermittent fuel pump issue and found the problem after replacing the pump.
 
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Tsandershsa

Tsandershsa

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A condition you describe could easily be a damaged or corroded wire in the pump harness on the Jeep side. Had a similar intermittent fuel pump issue and found the problem after replacing the pump.
I checked the loom and wires from the fuel pump plug to where they go over the transmission, couldn’t find any damaged wires… furthermore I tested the fuel pressure at the rail and it was 57 psi while running… could this be a ground problem and if so I’ve been trying to locate where it grounds…
 

DaEbLe

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I hate to say it, but I think you have the dreaded bad ground somewhere. Lol

The ground strap at the filler is for safety only. The filler is connected to the body, typically by plastic, and to the plastic tank by a rubber hose. So to ensure an isolated part is grounded the strap is ran. I'm curious if you are grounding out part of something else with the strap. As mentioned above you could be grounding out where the gas pump ground failed. I have noticed various body panels are not grounded from a factory sitting tub. So you could be grounding out something important. I would for giggles start running jumper wires from ground terminal to body, or to frame or to pump. When you find the spot of the jeep pump turns on reliably you can trace it to the faulty ground.
 
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Tsandershsa

Tsandershsa

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I hate to say it, but I think you have the dreaded bad ground somewhere. Lol

The ground strap at the filler is for safety only. The filler is connected to the body, typically by plastic, and to the plastic tank by a rubber hose. So to ensure an isolated part is grounded the strap is ran. I'm curious if you are grounding out part of something else with the strap. As mentioned above you could be grounding out where the gas pump ground failed. I have noticed various body panels are not grounded from a factory sitting tub. So you could be grounding out something important. I would for giggles start running jumper wires from ground terminal to body, or to frame or to pump. When you find the spot of the jeep pump turns on reliably you can trace it to the faulty ground.
I think it’s a ground problem also but it has been running fine now since Wednesday night…. been trying to track down grounding points and cleaning them… maybe it’s fixed!
 

DaEbLe

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If I remember correctly, the fuel pump ground runs in the harness that grabs your speedo off the tcase, then the trans connector and lockout, then moves through the upper and lower O2 sensors before making it into the engine compartment where a ground was connected to the firewall.
 
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