94 100 2.8 V6 issues

[Tony Hoffman]

You say it starts right up cold but has no power? While it has no
power, does it backfire through the intake? Does it smoke at all?

What happens when the O2 sensor is umplugged? If it runs better warm
then, part of the problem is the O2 sensor. However, it only comes
into play once the engine reaches a certain temp (usually about 2
minutes of running). Not too sure where the coolant temp sensor is on
that one, but that would definately be a good place to check as well.
You can ohm it out and see if it is within specs at different
temperatures.

Tony

On Thu, May 20, 2010 at 8:35 AM,  <dgraber460 at aol.com> wrote:
>
> Oh great list of wisdom;
> A friends 2.8 V6 recently broke the belt and bent the valves on the passenger head. the driver side head compression test was to spec so we only pulled the passenger side (budget constraints are in play here). We pulled the head, had a shop throw some valves in it and do a cursory check for other issues. We then put it back on with new gaskets, belts, t-stat, and water pump. It fired right up after reassembly, and we used the proper cam alignment bar when putting it back together.
> It will not run properly until warmed up. Idles OK, but no power till warm.
> It has been throwing two O2 sensor codes. "Regulation", "Regulation2". The plugs are nice and clean with no sign of richness. I'm guessing it has a temp sensor issue and doesn't richen up for cold running? But it starts well when cold. Confusing.
> I'm familiar with the I5's but not the V6's. Which sensor (or system) do I start with to figure this thing out? Yesterday it acted up after warm and lost power for a time on the highway. Their descriptions of the issues are a little difficult to interpret.
> I'll check the codes again this morning (cars not here yet this morning) but I need a diagnostic step by step to get this figured out.
> Any help greatly appreciated.
> TIA
>
> Dennis
> Denver
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