Fuel Issue

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Topic author
JRod81Cherokee
Posts: 34
Joined: Mon Mar 29, 2021 7:18 pm
Location: Oklahoma

Fuel Issue

Post by JRod81Cherokee »

‘81 Cherokee. I have a fuel issue, I believe.
I can drive it and then park it and then it will not start back up unless I spray starter fluid in it. It also just started dying when you let off the gas to slow down. Any help is greatly appreciated. I just wonder why it’s not priming and starting without help. Any ideas or where to start.
Has a new fuel tank, and pump.
Thanks in advance.
I roll in a 1981 Jeep Cherokee

will e
Posts: 5097
Joined: Sat Aug 18, 2012 8:21 am

Re: Fuel Issue

Post by will e »

Check for vacuum leaks.

Will it start if you 'pump' the gas? What if you stop the engine and then start it again? Does it start right back up?
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge

Topic author
JRod81Cherokee
Posts: 34
Joined: Mon Mar 29, 2021 7:18 pm
Location: Oklahoma

Re: Fuel Issue

Post by JRod81Cherokee »

It will not start by pumping the gas. I’ve only had it less than a year, so I’m not sure if it’s had these issues prior.
Once I get it started it will run fine. Sometimes when you let off to slow down it dies, but you can hit the ignition and it will fire back up.
It almost seems like it’s missing something in the fuel system.
I roll in a 1981 Jeep Cherokee

will e
Posts: 5097
Joined: Sat Aug 18, 2012 8:21 am

Re: Fuel Issue

Post by will e »

My guess is the accelerator pump is leaking. It's a small enough leak that it doesn't impact you restarting the truck engine right away but large enough that if it sits for a while the accelerator pump empties out. This would explain why you have to use starting fluid to get it going again.

Get the truck running. Turn it off and look down the throat of the carb while moving the throttle lever quickly. You should see a jet of fuel pumped out.

Restart the truck and let it run for a minute or so. Then turn it off and let it sit for a day or however long it usually takes for the no start condition. Then look down the carb throat again and move the throttle lever again. You should still see a jet of fuel, if you don't your accelerator pump is leaking.

What kind of carb do you have?
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge
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tgreese
Posts: 7118
Joined: Fri Jun 08, 2012 6:31 am
Location: Medford MA USA

Re: Fuel Issue

Post by tgreese »

V8 or six? Original carburetor?

Accelerator pump is possible if it's the original Motorcraft carburetor. I have found that these leak to outside when they fail, so the OP should look at the front of the carburetor for a possible leak. Kinda think you'd notice a bad accelerator pump while driving though.

Any car this old with a carburetor almost certainly needs the carburetor rebuilt, if it has not been rebuilt already.

I would start with the fuel pump. There is a procedure in the TSM for testing using a pressure/vacuum gauge, cheap from Amazon or local store. A new fuel pump does not rule out a fuel delivery problem.

Your TSM also has flow charts for no start that covers fuel and ignition. You need fuel and spark to start and run.

You can also test for fuel volume delivery, but it's probably not safe if you don't understand how to go about it and the risks involved.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
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marc
Posts: 178
Joined: Tue Aug 11, 2020 8:24 am

Re: Fuel Issue

Post by marc »

Had a similar problem with the BBD on my j10 258. It appears to have been resolved by a rebuild. Took it to Edmonds Auto Parts and Marine in Edmonds Washington.
Marc
J10 1984, very stock with AMC 258.
Truck appears to have been rebuilt or restored at one time

Topic author
JRod81Cherokee
Posts: 34
Joined: Mon Mar 29, 2021 7:18 pm
Location: Oklahoma

Re: Fuel Issue

Post by JRod81Cherokee »

I replaced the fuel pump already. I’ll check the accelerator pump.
It is original carb. I’m not sure if it’s been rebuilt or not.
Thanks for all the help!
I roll in a 1981 Jeep Cherokee

letank
Posts: 4010
Joined: Wed Oct 03, 2012 9:16 pm
Location: SF bay area

Re: Fuel Issue

Post by letank »

V8 or I6 ?

Which carb? may be post a pict

Also, how many months or years of ownership... is this a recent event?
Last edited by letank on Fri Jan 28, 2022 10:01 am, edited 1 time in total.
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
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oregonphil
Posts: 53
Joined: Sat Oct 17, 2020 11:42 am
Location: Klamath Falls, Or.

Re: Fuel Issue

Post by oregonphil »

This may not work for you, but I've been having the same problem with mine. If it sat for more than a day, it needed a spray of starter fluid. Also, would not start if I first pressed the gas pedal to close the choke. I thought I was flooding it.

Turns out it was starving for fuel. The gas was draining back into the tank when the electric fuel pump was turned off. So, I put a check valve in to keep some fuel and pressure at the carb. It's working right now.
Got this check at NAPA, it's all brass, compact and can be taken apart to clean out if needed. https://www.napaonline.com/en/p/NNPA0001Q
Hope this helps.

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1978J10REDWHITE
Posts: 263
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Re: Fuel Issue

Post by 1978J10REDWHITE »

Being it is a new rig You might consider doing what was already spoken about, the carb in these old of rigs are likely crapped Up inside and any inline filter in them partially or mostly clogged.
I realized early on, two things in jeeps and older vehicles, 1-fuel systems are almost almost all crapped up, tank to carb, and the vacuum lines especially the miles of them in jeeps are always leaky everywhere.
Like was said, Redo your carb anyway for your peace of mind and quality of future ownership, the filters underside to. Change it again in about 3-6 months too.
Then replace 100% vacuum lines in the entire rig, under dash and hood both, every single thing!
That will eliminate a lot of issues those two systems will definitely cause you.
It's your rig, Invest in the time, labor & parts. It's really not all that much if you do the labor.
Welcome to the club!
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