Sputters when cold under load

[03machstock]

Hey guys, having a little trouble with the 88. It does it primarily when cold, and only very rarely at operating temp, although it may be down a little on power when at operating temp. Anyway, it started a while ago and would only do it every now and then, but now, whenever the truck is cold, when a load is on the engine, it spits and sputters like crazy. Almost like something is arcing in the electrical system, but i can not find anything arcing, and it gets better when it gets warm. Any thoughts? Coil? Truck is 88 ranger 2.9 v6 5 speed.
Thanks,
Dan

 

[adsm08]

Ground a screw driver and then wave it around the coil to see if it arcs. My 88 BII did something that sounds similar. I ended up putting an enigne in it for top end issues and that fixed it. Mine would get better the longer it ran but come right back if you turned the engine off for 5 minutes.

 

[RonD]

When gas engines were switched to fuel injection they still needed a version of a "Choke" to use when engine is cold.
What they used was an ECT sensor, it is similar to the engine temp sender used for the dashboard temp gauge.
The temp sender has 1 wire connected
The ECT sensor has 2 wires.

Those 2 wires go to the computer(PCM) and tell it what the engine temp is, if it is cold then computer runs engine rich with advanced timing, just like the choke did on a carb.
As the engine warms up the computer leans out the mix and starts to use the O2 sensors for lean/rich measurement.

If the ECT sensor was telling the computer that the engine is warm all the time then you would get poor operation until engine actually warmed up.

This is an easy sensor to test with an OHM meter or Volt meter
read here:
http://oldfuelinjection.com/?p=28