53 M170 misfiring

iwojimavet · Post by **iwojimavet** » Sun Mar 25, 2012 8:59 pm

OK, I am not very engine savvy. Jeep ran smoothly last Fall. Jumped the two batteries today w/ my Yukon and got her started. Idled rough. Pushed in choke and ran a little smoother. Drove about 15 yds and she stopped moving and began backfiring terribly and loudly. Shut 'er down. Any suggestions? I am sure there's a lot! She has a 1/2 tank of gas.

Post by **wesk** » Sun Mar 25, 2012 9:21 pm

There's three ways to approach your problem!

1-Drop the jeep at the shop and have them fix it.

2-Sit here in front of the computer and each time someone throws out a possibility go out and try it. This is called the shotgunning method.

3-Open up the service manual for your jeep to the troublshooting section which has about 20 pages of help waiting for you to use it. Go to the section on engine runs rough and backfires and follow the detailed step by step chart until you nail the problem down. These charts are designed to start with the simplist, most likely and cheapest items to troubleshoot and goes through all the possibilities in an orderly fashion.

artificer · Post by **artificer** » Sun Mar 25, 2012 9:52 pm

What better advise could be available? But note to always start with electrical & ignition then finish with fuel.

MODIFIED · Post by **MODIFIED** » Sun Mar 25, 2012 9:59 pm

wesk wrote: This is called the shotgunning method.

My trigger finger is on "stand-by"

artificer · Post by **artificer** » Sun Mar 25, 2012 10:40 pm

Just for those not in the know "shotgunning" is an expression used when those trying to fix something haven't got a clue what is the cause of or how to fix the problem & go from pillar to post spending other folks money [usually].

MODIFIED · Post by **MODIFIED** » Mon Mar 26, 2012 12:54 am

iwojimavet · Post by **iwojimavet** » Fri Apr 06, 2012 12:15 am

Thanks guys. I'm assuming I want to use the TM 9-8014 Operational and Organizational Maintenance manual. I've got boxes of others if that's not the right one. In reading through it, I think I'll change the plugs first, and move on from there.

artificer · Post by **artificer** » Fri Apr 06, 2012 1:08 am

Sometimes I just can't help myself.
Have you checked the tyre pressure?
That has as much relevance as changing spark plugs.

Post by **wesk** » Fri Apr 06, 2012 11:42 am

TM 9-8014 has a couple of dozen pages of very clear written step by step troubleshooting procedures. You need to start at step one and proceed one step at a time. Page 80 Para C and D are where you should start. Run each step in Par c then if no joy run each step in Par d. There are 13 steps there and none of them direct you to change any parts unless the part is defective. Par's e & f do not really apply to your symptoms.

Arbitrarily selecting change spark plugs is a very good example of shotgun troubleshooting and throwing money and parts at a problem whose cause has not yet been determined.