truck suddenly started running like crap

[alwaysFlOoReD]

93 ranger 4.0l standard. Suddenly started running like crap on a traffic circle. Pulled over and let sit while I looked for anything obvious. Found nothing and have no tools with me....I just took them out this morning....go figure.
So if I let it sit for a minute it will fire up and run fine for about 30 seconds then starts crapping out again and eventually dies. Rinse and repeat.
Any ideas?

 

[saskbill]

Running like carp - sounds fishy!

Temporary crappiness gets better when you sit for a few minutes:

- fuel cap breather plugged?
- how long since your last fuel filter change?

 

[alwaysFlOoReD]

Loosened fuel cap, no difference. Not sure about filter but Schrader valve spits fuel onto the fender so lots of pressure. Its 38celcius maybe too hot?

 

[alwaysFlOoReD]

Rad fluid is good.

 

[alwaysFlOoReD]

Disconnecting IAC did nothing. Don't see any loose wires. The crank position sender wire has some exposed foil near the engine water outlet.

 

[ericbphoto]

No CEL? No codes? What about a vacuum issue?

This message composed solely of recycled electrons. Go green!

 

[alwaysFlOoReD]

No tools. I towed it home and will look at it in the morning.

 

[adsm08]

Oxygen sensor can do that. It is ignored for at least the first 30 seconds or so after startup.

 

[alwaysFlOoReD]

Thanks for the heads up.

 

[adsm08]

Thanks for the heads up.

I had one doing exactly what you describe a few years back. Never could figure it out until one night I am flying down the highway, had about 75 miles until I could get home, running stupid, and then BANG! it backfired and blew the cat shell open.

When I got down under it to fix the exhaust I found the O2 sensor was broken in two, and I suspect that was the root cause of all the problems.

 

[ericbphoto]

and then BANG! it backfired and blew the cat shell open.

I do believe that sudden noise would cause a mess in my pants.

 

[alwaysFlOoReD]

BANG! it backfired and blew the cat shell open.

I do believe that sudden noise would cause a mess in my pants.

Once upon a time in small town canada, before there was cats on vehicles, we used to cruise down the main drag. When we saw a unsuspecting prospect we would shut the ignition off for a few seconds and when directly beside the person turn the ignition back on. Boy it was fun for just turned pubescent almost adult hi-jinks....
Until I had to replace a muffler. That cost me money and I stopped doing it.

 

[alwaysFlOoReD]

adsm08; good call. The codes came back as o2 sensors, 172 and 176. I'll change them out hopefully tonight.

 

[1990RangerinSK]

I had one doing exactly what you describe a few years back. Never could figure it out until one night I am flying down the highway, had about 75 miles until I could get home, running stupid, and then BANG! it backfired and blew the cat shell open.

When I got down under it to fix the exhaust I found the O2 sensor was broken in two, and I suspect that was the root cause of all the problems.

My 85 did that. It'd been backfiring for a few days. Suddenly, I let off the gas to stop for a light, and BANG. When the light turned green, it was louder, so I pulled over and looked underneath. My brand new muffler was split right down the seam! I called and asked about warranty, telling them truthfully what had happened. Nope, no warranty.

 

[adsm08]

Once upon a time in small town canada, before there was cats on vehicles, we used to cruise down the main drag. When we saw a unsuspecting prospect we would shut the ignition off for a few seconds and when directly beside the person turn the ignition back on. Boy it was fun for just turned pubescent almost adult hi-jinks....
Until I had to replace a muffler. That cost me money and I stopped doing it.

Pfft, I knew a guy who did that in his early 40s.

My 85 did that. It'd been backfiring for a few days. Suddenly, I let off the gas to stop for a light, and BANG. When the light turned green, it was louder, so I pulled over and looked underneath. My brand new muffler was split right down the seam! I called and asked about warranty, telling them truthfully what had happened. Nope, no warranty.

That is pretty much how it happened to me. It went bang when I let off the gas to shift.