1981 Jeep Scrambler 4 Cylinder 2.5L 151 NOT STARTING!!

1981 Jeep Scrambler 4 Cylinder 2.5L 151 NOT STARTING!!

thedude

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Location
Michigan
Vehicle(s)
1983 CJ-7 AMC 360 V8, 1982 CJ-5, 1981 Jeep Scrambler, 1967 CJ-5 Tuxedo Park, 2012 Jeep Wrangler Sahara
So I have been lurking on this site for a long time and love all the friendly advice everyone gives on here, it is a really awesome community!!! Thought it was time I ask for some support myself.... I have had a CJ5, CJ7, wrangler, and now finally I got the one I have always wanted a Jeep Scrambler! Found it on Craigslist and somehow it was still available after 19 days online. I got it for a straight up trade for my 1997 Harley Sportster, which I estimate is worth maybe $3000?? SO I think I got hell of a deal. When I got there it definitely needed some TLC. The tank was out and the rear bed is rusted through really bad. All in all it wasn't terrible, just looked like it had been collecting snow, rain, and dust for awhile. I hauled it back to Michigan from Central Illinois and started going through it.... It washed up awesome. This thing is all original everything! Some rust holes in the floor and needed a fuel system overhaul, but man am I happy... I think I could sell it right now without it running for 10k (like I would ever sell it).

Anyways, to the issue at hand! I installed a new gas tank, new gas lines, new fuel pump, new starter, new battery, removed emissions and wallah one day it cranked and started after throwing gas down the carb and I let it idle and run for about 30 minutes. It ran really high RPM, but it was this winter so it was cold... so whatever, it eventually backfired a couple times and I turned it off...

Go to try it a couple weeks later and nothing... it just cranks and cranks and nothing. So I said screw it, I will start overhauling all of it ....

- Changed rotor, dist cap, ICM, Ignition Coil, spark plugs, plug wires, changed the oil, new fuel filter, new carb (rochester varajet II), capped off the vacuum lines, new valve cover gasket, new master cylinder... and I am still in the same situation. Still just cranks and cranks. IT WILL START if I pour gas in the carb and then it will just run out a few seconds later...

IT MUST have spark if it starts when gas is poured in the carb, right? Is this a fuel issue? Is the pump just wimpy and not putting enough fuel out? Is the fuel old and crappy now and doesn't start cause of that(has been sitting a few months)? I am scared it is not starting because of timing. That would not keep it from starting would it? That is probably something out of my skill level...

Any suggestions, let me know! This engine --- the 81 Iron Duke 151 2.5l is hard to get information or photos on.

Someone also said that it could be the ignition switch, but wouldn't it not start at all if it was the switch? Like I said it starts when gas is poured directly into the carb. When I hit the accelerator it sounds like there's gas squirting into the barrel. So I don't think it is the accellerator pump... I don't know. Sorry for all the information. Please help, thank you!
 
So if you pour some gas down the carb and it starts until it burns up that gas you have fuel problem. Start at the carb unhook the fuel line at the carb and do it and see if you are getting gas to the carb. If you have gas coming out of the line it's in the carb and if no gas start working back. Unhook the line from the fuel pump on the carb side and see if you are getting gas there. If not you may not be getting from the tank could be a pinched line.
 
Sounds like carb/gas issue



Look down the carb and open accelerator all the way you should see gas squirt into carb, if not which is what I suspect then you could have a problem with a stuck float or bad pump


I would think that as long as your motor has sat the carb needs a rebuild tho


Sent from my iPhone using Tapatalk
 
Gotcha! Thank you for the troubleshooting tips! I figured it had to be that, just wanted to get some confirmation before I start tapping into more things... I’ll pull the fuel pump and put a different gas line to the carb and check the flow to make sure it’s not pinched. If that’s not it I have the old carb and the rebuild kit sitting next to it ready to go.

I’ll give that a shot and report back. Thanks again!
 
Is there any fuel in the float bowl? Something is plugged or sucking air.
 

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