An engine needs thre things to run
Air, Fuel, Ignition source
Air is a given unless your covering the air cleaner with a bag.
Fuel - about the only thing you didn't replace was the tank, so I would
say your OK there

The symptoms point to a heat related failure. Some component is getting
hot enough to shut down the engine.
Since you still have fuel pressure when the engine dies it isn't a bad
pump.
It also isn't likely the EGR since they don't normally shut down an
engine and then clear up when they get cool. They are either stuck open
(which causes REAL bad idle on the 4.3 and an engine that will not idle
hot or cold) or they don't work at all.


Ignition?
You said you found a cruddy wire end. One usually won't do much but
cause missfiring in that cylinder. I has a problem with the wifes 94 4.3
that was a bad set of plug wires. It caused massive missfiring but no
real problem with running or acceleration. Just bucking under load.
(common symptom FYI).

Bad plugs- Not likely since they fire OK when cold. Plus for the engine
to quit they all have to stop working.

Plug wires- Same as above BUT they could cause crossfiring.

Cap - Usually causes missfires if the cap is bad.

Rotor - possible but not real likely.

Coil- very possible- it could be shorting out internally when it gets
warm enough.

Ignition Module - possible for the above reason, but they usually just
fail.

Computer - It's not showing codes which is not unusual for an OBD I.5
vehicle (oddball that GM used in 95 on some vehicles) they mainly show a
code only when an item totally fails, unlike OBD II that can tell you
that a sensor is just getting weak. It could have a bad connection on
the main connection though.

Main wiring harness connection on the firewall - It has been a culprit a
few times for heat related problems. It gets warm and the connection
opens.

It is also possible that it could be a bad connection to one of the
above components.

--
Steve Williams

> wrote in message
oups.com...
> Summarizing
>
> Fuel/Ignition/Other? Please help
>
> I have been trying to figure this out with no success. Can you guys
> take a look and offer any suggestions you might have?
>
>
> Vehicle:
> 1995 CHEVROLET TRUCK ASTRO VAN
> 2WD Automatic Transmission
> 6 Cylinders 4.3L CPI
> 105,000 miles
>
> Symptoms:
> The van always starts and runs fine for at least a minute or two.
> However after a short distance it will not accelerate properly and it
> will try to stall. As it progresses I might get some popping at the
> engine and eventually it will die. When I press the accelerator it
> acts like it wants to die.
>
> It takes as much as 10 to 15 minutes of regular city driving to cause
> these symptoms or 2-3 minutes of driving under a load (when I hot-rod
> it). It does not seem to be directly related to engine temperature.
>
> If the van completely dies, I can turn it off for 10 seconds then
right
> back on and it definitely drives better (not completely normal). If I
> leave it off for 15 minutes it usually runs quite a bit better.
> Overnight and it runs normal when I first start it.
>
> Parts Replaced:
> Leaky CPI (spider)
> Inlet outlet fuel lines (nut kit)
> Fuel Filter
> Fuel Pump and strainer
> Exhaust from O2 sensor back
> Drained the gas
> Ignition coil
> PCV Valve
> Tune up (plugs,wires,cap,rotor)(6 months ago)
> Oxygen sensor (6 months ago)
>
>
> Current Diagnostic (I am a complete armature so some/all items could
be
> irrelevant)
>
> EGR (sticking)
> Tapping/ticking started after I removed/checked this. I am pretty
sure
> I just need to take it off again and clean or replace. I do not
> believe this is my main problem because I took it off, closed the
> valve, and reinstalled without hooking it up. This test did not
change
> any of the symptoms listed above.
>
> Distributor
> I just examined the distributor and one of the plug wires and probes
on
> the distributor was severely corroded; the rest were fine. I will
get
> a new cap and wire tonight and check the plug.
>
> Fuel Pressure
> Test with a fuel pressure gauge. After sitting overnight, turn key
on
> and I get 62psi pressure (in spec). Turn key off and it holds 25psi
> pressure (there is no spec that I know of for this).
> While running it never drops below 50psi (in spec) even when it is
> acting up. While it is acting up and I accelerate the needle will
> sweep between 50psi to 70psi very fast.
> What concerns me is that after it is acting up and I turn the key off
> the fuel pressure instantly DROPS to 0psi. It this an issue?
> If I let the van sit for two minutes and turn the key on (pump on)
then
> back off again it will still drop to 0psi. If I let it sit overnight
> it will again hold 25psi of pressure with the key off.
>
> Codes
> The check engine light (service engine soon) does work, but does NOT
> turn on. I do not get any codes. To verify I rented an "Actron
> Super AutoScanner" and checked the codes. I do not get any.
>
> I know I can monitor real time data with this device (scanner) but I
do
> not know what to look for (suggestions?).
>
>
>
> Do you guys have any suggestions on what to try next? I am about out
> of ideas and I am thinking about taking it to the shop. If/when I
take
> it in, do you have and advice on what type of shop or diagnostic test
I
> should ask them to run (or not to run)?
>




----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----