YJ stumbling intermittantly

[camcdaniel1]

95 YJ 4.0 runs fine for a few miles then starts to stumble and back fire. Can turn key off and back on and runs fine for a few more miles before stumbling again. Replaced fuel filter and MAP senser to no effect.
Any ideas greatly appreciated!!!

 

[jfrabat]

Have you checked the ignition? Coil went bad on me once and the description is similar... Could also be a fuel pump (check fuel pressure and you will find out quickly enough) or a clogged up cat (although I would not think cat by the fact that if you turn the key on and off it starts again). Possible an ECU or bad ignition switch also... And last, have you checked that the battery terminals are good? Kind of basic, but I have overlooked that one before...

 

[camcdaniel1]

Tell me this anit strange. I filled up the tank and it quit stummbling till the fuel level drop back down. Could this be a tank vent issue?

 

[Bounty__Hunter]

I had a similar problem and it was a hole in the rubber line between the fuel pump and the top of the sending unit, INSIDE the tank. It would suck air unless the tank was full.

 

[SteelHeadz]

I had a similar problem and it was a hole in the rubber line between the fuel pump and the top of the sending unit, INSIDE the tank. It would suck air unless the tank was full.

This makes sense.

 

[jfrabat]

I had a similar problem and it was a hole in the rubber line between the fuel pump and the top of the sending unit, INSIDE the tank. It would suck air unless the tank was full.

I wonder what created the hole in the first place... Would be interesting to know so as to avoid this situation.

 

[Bounty__Hunter]

Some type of dry rot is best I can figure.