Jeep acts like its running out of fuel.. - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep CJ Forum > Jeep acts like its running out of fuel..

XHD Heavy-Duty Hood Latches for JK and TJ available at OcoRough Country Lift Kits and Parts!Clayton Off Road WJ Long Arm Kits!

Reply
Unread 03-09-2012, 02:08 PM   #1
Swampwalker3
Registered User
1987 YJ Wrangler 
 
Join Date: Nov 2006
Location: Gainesville, Florida
Posts: 749
Jeep acts like its running out of fuel..

The jeep recently started acting likes it's running out of fuel even though I ve filled her up.

The carb is fairly new, edlebrock, but has been running like a champ since I got the jeep.
Backstory: She still starts up fine cold or after it has been shut off for a short period of time. Ever since I got the jeep, it would be hard starting if she has been warmed up and then shut off for a lil, say drive to walmart, then try to start it after you checked out. But if I start it when cold, recently shut off, or after a good while (not cold but not hot) it starts fine. I figured the heat was boiling the fuel in the bowl as Ive read that was a common problem.

Otherwise the jeep ran fine. Monday the jeep acted like it was low in fuel so I filled it up (No gauge) and went on my way. It still continued to stumble and still does.
Seems like if Im at a decent cruising speed (45-50mph) she does it a lot. At a light it'll do it randomly as well when Im at a slow cruise. If I gun it, it reacts fine until you get a cat-like Hiss out of the exhaust. Under load up a hill is generally fine as well though it may or may not stumble.

This happens hot or cold. I have a fairly new MSD ignition module coild is still fairly new and all the plugs are pretty.

Im going to change the fuel filter just because I have one anyway, and I was kind of thinking it may be the manual fuel pump but wouldnt it be hard starting most of the time if it were bad? Imma smell the oil and see if it smells like fuel. No vacuum leak.

Any ideas? There is very little electrical on this thing. Coil, Plugs, Ignition, and lights make up all of the electrical components.

__________________


Zane Neher
88 YJ. H.O. 4.0L/AW4/twin sticked d300/1 tons/38.5s.
Swampwalker3 is offline   Reply With Quote
Unread 03-10-2012, 05:48 AM   #2
mylittlecj5
Registered User
1974 CJ5 
 
Join Date: Jul 2008
Location: Bethany, OK
Posts: 699
It does sound like a fuel boiling problem, get it hot, shut it off and watch inside the carb throat to see if fuel is dumping into the intake. If it is, get a non-metal carb spacer and see if that makes a difference.
Other things to consider:
I'd open the carb up and see if the needle jets/float bowls have any crap in them.
Check the output of the manual pump and see if it is giving you enough fuel at above idle RPM's.
Timing issues? Maybe the dist. is loose or the timing chain slipped a tooth?
__________________
Default Jeepers Club #10
mylittlecj5 is offline   Reply With Quote
Unread 03-10-2012, 05:53 AM   #3
nshefbuch
Registered User
1982 CJ7 
 
Join Date: May 2009
Location: piqua, OHIO
Posts: 1,865
What year? In my old 62 cj5 the fuel line was original and developed a pin hole so when driving I would periodically have cutting out issues. I located the pin hole but several times another hole would develop. I had to change all the fuel line to fix the problem.
__________________
82cj7 / soa wrangler springs / amc 360 / t18a granny / d300 twin stick / 37" pitbull rockers radials / h1's / 3/4ton d44 with high steering / 14 bolt ff / clocking ring
nshefbuch is offline   Reply With Quote
Unread 03-10-2012, 07:45 AM   #4
bigred513
Registered User
1979 CJ7 
 
Join Date: Jun 2011
Location: Huntsville, alabama
Posts: 20
Mine was doing the same right after i bought it. Did the same as you just kept filling it up. Changed the fuel filter. After replacing the fuel filter take the hose off going to carb and put it into a glass jar, turn you motor over and see if you are getting fuel. If you are getting fuel you should be good. It sounds like you might wnat to try this after you are at operating temp. Also I would check what others have said with your carb.

My problem turned out to be a problem with the tach wiring. Traced it down and rewired with a new tack and it ran like new again.
__________________
1979 CJ7 304
bigred513 is offline   Reply With Quote
Unread 03-10-2012, 01:47 PM   #5
Swampwalker3
Registered User
1987 YJ Wrangler 
 
Join Date: Nov 2006
Location: Gainesville, Florida
Posts: 749
My jeep actually has a 318 in it.
I stuck a clear filter on to see if any fuel is going through and it is. It filled up then once she got warm the filter was looking empty. Not sure if this is normal or if it should be full all the time.

I checked the lines to see if any were hard and cracked. I havent been running a tach for the past 2 months and the PO didnt have it hooked up.
I meant to check to see if the dist was tight but forgot.
I'll have to check my timing, if the chain jumped would that tell me or do I have to pull the cover?
I smelled the oil and found no traces of fuel.
__________________


Zane Neher
88 YJ. H.O. 4.0L/AW4/twin sticked d300/1 tons/38.5s.
Swampwalker3 is offline   Reply With Quote
Unread 03-10-2012, 02:00 PM   #6
Swampwalker3
Registered User
1987 YJ Wrangler 
 
Join Date: Nov 2006
Location: Gainesville, Florida
Posts: 749
Also, this is happening even if the jeep is still cold.
__________________


Zane Neher
88 YJ. H.O. 4.0L/AW4/twin sticked d300/1 tons/38.5s.
Swampwalker3 is offline   Reply With Quote
Unread 03-13-2012, 05:41 PM   #7
Swampwalker3
Registered User
1987 YJ Wrangler 
 
Join Date: Nov 2006
Location: Gainesville, Florida
Posts: 749
After testing for spark from everything and making sure I have proper fuel, I was looking at wires and noticed that the MSD pickup wires that go to the dist. weren't protected at the plug end to the MSD. Both wires (Green & purple) though plugged in all the way still had metal exposed. It was sitting under the MSD box and since the running out of fuel feel was sparatic, I was thinking maybe the metal on the wires were contacting the metal on the battery tray.
Can these wires "ground" out and interrupt the magnectic flow?
__________________


Zane Neher
88 YJ. H.O. 4.0L/AW4/twin sticked d300/1 tons/38.5s.
Swampwalker3 is offline   Reply With Quote
Unread 03-13-2012, 06:14 PM   #8
offroadz
Registered User
1980 CJ7 
 
Join Date: Mar 2011
Location: chandler, az
Posts: 279
Who did the timing on it? Mine is doing the same thing but really think the timing is way off on this thing. I'm going to have it timed properly as one post states on here also to make sure.

Let us know what you found out.
offroadz is offline   Reply With Quote
Unread 03-13-2012, 07:07 PM   #9
jimdubose
Registered User
1978 CJ5 
 
Join Date: Dec 2008
Location: Palmetto, Florida
Posts: 418
didja look inside the tank? if your fuel gauge isn't working and everything around the gauge seems wired and grounded properly, it would be logical to assume (bad word, I know) that you haven't looked to the sending unit to be that problem, hence, indicating you haven't looked at what it is like inside there. when i had problems stumbling under a load, and after replacing filters and the fuel pump, at the suggestion of someone here, I pulled the tank and found it full of sand and crud from the PO's joyous mud riding adventures. cleaned it out, passivated it, POR'd it got the sending unit working, replaced the sock filter, replaced some bad return fuel line (rubber at the tank), put it back together, problem gone. just a thought.........
jimdubose is offline   Reply With Quote
Unread 03-13-2012, 07:25 PM   #10
Swampwalker3
Registered User
1987 YJ Wrangler 
 
Join Date: Nov 2006
Location: Gainesville, Florida
Posts: 749
I haven't checked timing yet. Misplaced my gun and waiting for a buddy to lend me his next time we meet up.

I haven't looked in the tank yet but once I run low in fuel again I will. I need to pull it to install the sunpro sender anyway.

what throws me off is how random it is. Yesterday it ran great each time I drove it. today it stumbled this morning on my way to work for a block but stabled out again. On my way home and errands, it ran great. I dont get any stumbles under load if shes running fine. It's random and happens when it wants. Starts up each time as if it were EFI except after that certain length of time. Ive always figured it to be boiling on that incident though.

I guess I'll replace the lines and open up the tank.
__________________


Zane Neher
88 YJ. H.O. 4.0L/AW4/twin sticked d300/1 tons/38.5s.
Swampwalker3 is offline   Reply With Quote
Unread 03-13-2012, 09:29 PM   #11
greengiant1
Registered User
1947 CJ2A 
 
Join Date: Feb 2011
Location: lancaster, CA
Posts: 59
When it will not start, look down the carb, open the throttle briskly. If you see fuel spray from the accelerator pump, you have fuel. If so engine may be flooded or you do not have proper fire or properly timed fire. IF NO fuel from accelerator pump look at pump filter and line issues. Remember to run, you need a proper fuel/air mixture and fire. Once had a cj3 jeep in our club that always developed fuel problems on every outing. We got tired of the hassel and removed the tank. What we found was a toy plastic indian holding a rifle in his outstreched arm. We put the indian in a glass of gasoline. It sort of floated, not on top of gas and didn't sink to bottom either. It would float with the rifle pointing down. We theorized it would float around and the rifle would go down the sucking fuel outlet hole. Engine would die. With engine off the indian would just float away to cause havoc on another day.
greengiant1 is offline   Reply With Quote
Unread 03-13-2012, 09:52 PM   #12
Swampwalker3
Registered User
1987 YJ Wrangler 
 
Join Date: Nov 2006
Location: Gainesville, Florida
Posts: 749
The no start issue happens if she's warmed up, if I were to say park and go into walmart for a lil and come back out, it'll turn over a few seconds and starts right up. But Started for the first that day fires right up like it was EFI or if left sitting for awhile, it'll start right up as well. I read that the fuel in the bowl is boiling off which is what causes the few second starting.
Had that since day one, but never really cared on that.

I will drop the tank though, perhaps the sock is dirty if nothing else. I know Im getting fuel though to the carb. I can also see it in the clear filter as well.
__________________


Zane Neher
88 YJ. H.O. 4.0L/AW4/twin sticked d300/1 tons/38.5s.
Swampwalker3 is offline   Reply With Quote
Unread 03-14-2012, 06:51 AM   #13
82JeepCJ7
Registered User
1982 CJ7 
 
Join Date: Jun 2010
Location: Marysville, WA
Posts: 4,853
A lot of people are having issues with older vehicles due to all the crap (ethanol) they are putting into gas now. Try running a few tanks of ethanol free gas through it and see if that helps after you get the tank squared away.

http://pure-gas.org/
__________________
Beat it to fit, paint it to match!

Wheel, Wrench, Repeat.
82JeepCJ7 is offline   Reply With Quote
Unread 03-14-2012, 09:31 AM   #14
cj5752
Registered User
1975 CJ5 
 
Join Date: Sep 2008
Location: Arkansas
Posts: 220
Is the choke open completely when engine is warm?
cj5752 is offline   Reply With Quote
Unread 03-14-2012, 09:53 AM   #15
tantan123
Registered User
 
Join Date: Mar 2012
Location: us, New York
Posts: 13
I'd open the carb up and see if the needle jets/float bowls have any crap in them.
tantan123 is offline   Reply With Quote




Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.