Need help with a start-up problem

Reidminer

Reidminer

TJ Enthusiast
Joined
Jan 9, 2019
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376
Location
Syracuse NY
Hi all, so in the past 2-3 weeks I’ve noticed an issue with starting my Jeep, only in certain situations though.
going to work in the morning, first turn of the key, it won’t start. It’ll turn over, it sounds like it should, but never fires up(in the past few weeks that is). If I then let it sit for a few seconds, and turn it over, it’ll start no problem, without fail.
If I then say am running errands, and the Jeep sits for 15-30mins, it’ll still start up fine, but longer than that and it’s back to first turn over not working. So is this a spark plug issue, or fuel related? Any help would be appreciated.
I’ve got the 4.0 5 speed manual in an 01 sport
 
Sounds like fuel pressure leakdown. The first culprits I'd suspect are the check valve in the fuel pump and leaky injectors. I replaced my fuel pump 2 years ago and I just replaced my injectors with remanufactured ones from K Suspension Fab yesterday and my long start issue is gone. However, I don't recommend just throwing parts at it. Get a fuel pressure gauge and try to find the culprit.
 
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SecondChanceTJ said:
Sounds like fuel pressure leakdown. The first culprits I'd suspect are the check valve in the fuel pump and leaky injectors. I replaced my fuel pump 2 years ago and I just replaced my injectors with remanufactured ones from K Suspension Fab yesterday and my long start issue is gone. However, I don't recommend just throwing parts at it. Get a fuel pressure gauge and try to find the culprit.
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Huh okay, I’ll check that out! Fuel pressure gauge something a place like napa or advanced auto loans out?
 
Reidminer said:
Huh okay, I’ll check that out! Fuel pressure gauge something a place like napa or advanced auto loans out?
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I do not know. I'm the numbskull that threw parts at the Jeep until the problem was fixed. When you get your hands on one though, there should be a Schrader valve on your fuel rail depending on year model.
 
Definitely sounds like the drain back valve in your fuel pump unit is going bad.
 
Chris said:
Definitely sounds like the drain back valve in your fuel pump unit is going bad.
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That's what I was told back then, and then I changed the fuel pump and still had the issue. Very well could be the cause, but that's why I recommended diagnosing first.
 
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Reidminer said:
Gotcha, thanks for the input. Like y’all recommended, I’ll get a gauge to check it and go from there. My dad very well may have one lol. If not I’m sure it’ll be worth the investment
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When i used to work at Oreillys we had a fuel pressure gauge we would rent out. Pretty sure advanced and Napa does the same thing. Just call them before you visit.
 
So last weekend I hooked up the fuel gauge I loaned from O’reillys, and upon turning the key to the on position without turning it over, it didn’t seem to kick the pump on. Once I did the cycling through of the ignition to get it to start, it holds pressure fine where it should, but once it’s turned off it rather quickly loses its fuel pressure. My dad is thinking it’s related to the check valve. Is that an individual part I can replace or would it be best to just get a whole new fuel pump? In either case, is there a specific brand that makes good replacements for these?
 
Reidminer said:
So last weekend I hooked up the fuel gauge I loaned from O’reillys, and upon turning the key to the on position without turning it over, it didn’t seem to kick the pump on. Once I did the cycling through of the ignition to get it to start, it holds pressure fine where it should, but once it’s turned off it rather quickly loses its fuel pressure. My dad is thinking it’s related to the check valve. Is that an individual part I can replace or would it be best to just get a whole new fuel pump? In either case, is there a specific brand that makes good replacements for these?
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Yea sounds like the problem I had with my check valve. The pump only cycles for like a second when the key is on the on position so its not enough to fully prime the line. My money is on the check valve.

check valve is in the pump assembly so the whole thing would be needed replaced. I recently replaced mine with a DELPHI one and its been great.
It was the delphi FG1353 and I got it off rock auto
 
Winks42 said:
Yea sounds like the problem I had with my check valve. The pump only cycles for like a second when the key is on the on position so its not enough to fully prime the line. My money is on the check valve.

check valve is in the pump assembly so the whole thing would be needed replaced. I recently replaced mine with a DELPHI one and its been great.
It was the delphi FG1353 and I got it off rock auto
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Gotcha okay. Yeah figured if I had the tank dropped and it’s the original pump I might as well replace it but yeah that makes sense. And awesome thanks for the part info, I’ve seen in threads Delphi pumps recommended but couldn’t get and exact type
 
Chris said:
Definitely sounds like the drain back valve in your fuel pump unit is going bad.
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Yep, sounds like leak down. To be fair mine has been doing this for 5 years. I just turn the key to prime it for a few seconds and then it fires right up. I will probably end up replacing the fuel pump at some point, but since this is a "toy" and not one I depend on for a daily driver I'm not too worried at this point.
 
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BLindzy said:
Yep, sounds like leak down. To be fair mine has been doing this for 5 years. I just turn the key to prime it for a few seconds and then it fires right up. I will probably end up replacing the fuel pump at some point, but since this is a "toy" and not one I depend on for a daily driver I'm not too worried at this point.
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Ah gotcha haha. Yeah it only started doing this about a month ago now, where on the first turn over it won’t start(no matter how long I prime it) but on the second turnover it’ll start easy peasy. Problem is this is my DD as well as fun toy so I sorta need it working it’s best lol. From the looks of it the Delphi pump isn’t terribly expensive and replacing it shouldn’t be terribly hard. We’ll see!
 
Reidminer said:
Ah gotcha haha. Yeah it only started doing this about a month ago now, where on the first turn over it won’t start(no matter how long I prime it) but on the second turnover it’ll start easy peasy. Problem is this is my DD as well as fun toy so I sorta need it working it’s best lol. From the looks of it the Delphi pump isn’t terribly expensive and replacing it shouldn’t be terribly hard. We’ll see!
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Sounds like you have a plan!
 
Reidminer said:
Ok cool, yeah like someone else mentioned, is Bosch still making them? I thought the Oem pump was discontinued
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Winks42 said:
I thought they discontinued the Bosch pump?
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There are several year-specific models but I replaced my pump (just the actual pump, not the whole module) with a Bosch not too long ago. I also have been seeing Bosch’s replacement full module on Amazon for a while (for 2004). Not sure about these parts for a 2001 model but it’s worth looking into.
 
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