82 CJ-8 Cranks But Won't Start

City
Fayetteville
State
AR
#1
Hi guys,

My 82 CJ-8 sat for about a year and half before recently firing it back up. I put in some new gas, but did not drain the old before running it( that was dumb). It started and ran just fine for about 3 weeks, and just recently won't start. It will crank, but will not fire. If I spray some carb cleaner into the carb, it will fire up and run with no issues. But if I shut it down and don't start it up again within about 30 minutes, it won't fire again.

Does this sound like a carburetor issue, or something else wrong with the fuel system? I've seen in a couple of threads from way back, concerning similar issues, that the fuel pump can be a suspect as well.

Just need a spot to start from to get it running again

Thanks,
C
 

mssldn

Legacy Registered User
City
Gooding
State
ID
#2
Did you run a full tank of gas through in the 3 weeks it was running? You know it is fuel related because it runs on the carb cleaner. Have you tried running a hose from your fuel pump to a separate gas can? If that doesn't work move up the line. Try to gravity feed the carb.

If it runs by gravity feeding then your pump is bad. If it runs out of the gas can from your pump, you probably have bad gas.
 

ag4ever

Average Nut
LIFETIME
CJ-8.com Member
City
Richmond
State
TX
#5
I had similar symptoms, it turned out my fuel tank had crud in it from the ethanol.

The fuel filter in the tank was clogged and looked like a swamp monster was living on it.
 
City
Fayetteville
State
AR
#7
Tried gravity feeding the carb...still wouldn't start, and the fuel pump was pushing fuel that looked pretty clean. There's another filter between the pump and the carb, so I guess I'll move up the line and replace that and see what happens.
 

HighSierra CJ

Scrambler Enthusiast
LIFETIME
CJ-8.com Member
City
Ducor
State
Ca
#8
Tried gravity feeding the carb...still wouldn't start, and the fuel pump was pushing fuel that looked pretty clean. There's another filter between the pump and the carb, so I guess I'll move up the line and replace that and see what happens.

Are you running a four-cylinder or six cylinder?

The reason I ask, is that the four-cylinder carburetor has a fuel filter In the carburetor, right where the fuel line hooks up. Most people don’t realize that.
 
City
Fayetteville
State
AR
#10
Hi there folks,

An update:

It occurred to me that even if the fuel pump is pushing fuel, it may not have enough pressure to get the fuel through the filter that is between the pump and the carb. So, I removed the section that had the second filter, and put the hose directly to the carb and BOOM! Now it will fire right up. Looks like the pump will push fuel, but not with enough pressure to get it through the second filter.

Now I'm needing a couple of other pieces of advice..

1. Should I keep the filter that is in between the pump and the carb? There is a filter just before the pump as well( I'm going to go ahead and replace), so I don't know if the second one is really necessary.

2. Where is the best place to get a new fuel pump? Any particular brands/specs I should think about when looking?

Pictures below showing how things are set up...

First picture is an overall picture. You'll see the pump in the lower left, with the first filter just before it.

Second picture is the pump itself.

Third picture is showing where the second filter was before I removed that particular portion of line.
 

Attachments

Randyzzz

Blown Budget
LIFETIME
CJ-8.com Member
SOA Member
City
Redmond
State
OR
#11
I doubt the second filter would restrict the flow enough to keep the float bowl from filling, unless the filter is plugged. Been years since i have done carbs, but I remember most factory filters were between the pump and the carb. Sounds like a weak pump. You might want to check pressure and volume before replacing the pump, however if you have to buy a pressure gauge I'll bet a pump is cheaper.
 
City
Fayetteville
State
AR
#12
Replaced the fuel pump, and it's starting right up now. Thanks a ton!

Now I've got the slightest leak at the top of the pump where the outflow line screws in..I've been as careful as I could be about keeping it from cross-threading, but no matter how straight I keep it, it's got some fuel seeping out. Should I use some thread tape or is there a trick to it?
 

Attachments

jammer1

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
Maple Hts.
State
Oh
#13
The flare of the gas line or the seat where the gas line sits may have a nick (or the line has a seam that's not smooth). If you find that, fine sand paper may clean it up. The flare is what seals it up. A pic Of both ends would help.
 

Spieg

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
Aurora
State
CO
#14
Do you have a return line to the gas tank (not sure if they did in 82 or not.. it looks like a plastic tube going down to the driver side frame rail)? If so, you need the fuel filter between the pump and carb (it will have 3 ports - one from the pump, one to the carb and the third goes to the return line).
 
City
Fayetteville
State
AR
#15
Do you have a return line to the gas tank (not sure if they did in 82 or not.. it looks like a plastic tube going down to the driver side frame rail)? If so, you need the fuel filter between the pump and carb (it will have 3 ports - one from the pump, one to the carb and the third goes to the return line).
I don't recall mine ever having a return line..doesn't mean it didn't at one time but I've not seen it.
 

bigwalton

Picture cravin' AK Postal nut
Staff member
SOA Member
City
Dexter
State
MI
#16
There’s no need for the filter before the pump and my guess is that it’s causing the issue by starving the pump. Leave the one after the pump and run the return back to the tank as it is stock. No filter before the pump. The stock pump setup need not be messed with if you’re sticking to the stock mechanical pump IMO.
 
City
Bridgman
State
MI
#17
Replaced the fuel pump, and it's starting right up now. Thanks a ton!

Now I've got the slightest leak at the top of the pump where the outflow line screws in..I've been as careful as I could be about keeping it from cross-threading, but no matter how straight I keep it, it's got some fuel seeping out. Should I use some thread tape or is there a trick to it?
I had the same problem. I cut the end off and put a new flare on the end. It needs to be a double flare like on your brake lines. The double flare will make it a little thicker and seal tight. Yes I would use some thread seal. If you do not have a good flare tool take the little piece of metal tube to a locale shop and have then do it right. A good flare tool will cost more than having them do it.

Best
 
Top