I've got a 1994 E350 cube van with the 460 in it. I've owned it for a 3 years now and have had a few issues with it since I bought it..
When I first got it the check engine light was on. Pulled codes. EGR was stuck shut. Didn't have time to fix it at the time so I drove it on about a 700 mile trip to VIR. I knew with no EGR the engine might knock a little so I was careful. Very minor pinging going up some of the larger hills by Scranton PA. BUT the engine ran very good and did not surge/cutout at all.
Got back from trip and put new EGR valve on . No more check engine light.
I started driving it on shorter trips and noticed a very minor surge/cutout once the engine was fully warmed up. Almost like the engine was being turned off for a split second. Other than that it ran great and went on another long trip. The occasional cutout was still there but very infrequent and not really an issue.
Decided I would try and resolve this issue and with 195K miles on it it was time for a tune up. New plugs, cap, rotor, fuel filter, air filter.
Another long trip and cutout is still there.
Decided to replace pickup in distributor, coil and TPS. And I had my ignition module tested at Advance auto. The machine actually heats it up. It tested good.
Yesterday I hooked up my vacuum guage, fuel pressure guage and timing light to see if how things looked. Fuel was in the low 30's. Pulled vac line and jumped up to the low 40's. Vac was around 18-19 and steady.
NOW heres the questions
1. When the check engine light is ON does the computer use all the sensors to determine fuel and timing OR does it go into a fixed mode. Maybe you see where I am going here. When the check engine light was on (EGR) the engine DID NOT cut out ever.
2. I am thinking of replacing the Coolant temp sensor. I think I tested it thou and the resistance was in spec when it was cold/warm. I did not test it hot. I say think because there are 2 sensors that are on the manifold that resemble a CTS. The wiring diagram does show wire color so I think I got the right one. Do you know which one it is?
3. Is there an Air charge temp sensor? The wiring diagram shows one. Maybe this is the one that is next to the CTS.

Soooo?. Sorry for the novel!! Just want to put out as much as I know.

A few more notes. The cutout does not happen at full throttle, only light to medium load and only once up to operating temp.
I still think I may replace the ignition module even thou it tested good.
I did replace the MAP as well.