Need advice in area I have never messed with "Fuel Injectors"

[captn38]

First let me say I am the second owner of my 93 Delsol Si, purchased in 1997 with 60K miles on it, first owner was meticulous and had all service work done at Honda dealership ( she was one of those people who bought a new car every 3 years regardless ) she bought a 97 delsol and made me an offer I could not pass up. I have been very meticulous with the care maintenance of this 93 for the last 16 years, the car has been kept all OEM and 100% complete the only things I have had to replace on it due to wear or fatigue is one rear wheel hub assembly, radiator, starter, distributor most of which just happened in the last 3 years. I do not run it hard, all highway miles, nothing but full synthetic lubricants, all filters are changed periodically etc you get the picture its been well taken care, but no garage queen either.

Now to give you a little of where I stand I have always done all my own work and have been for almost 40 years, I was raised on Fords and old school vehicle technology but I try to adapt :^)

About 3 years ago and at approx 180k miles my delsol started experiencing a stutter/miss at low rpm (2700 and under) under a load, my first thought was fuel delivery issues and I embarked on testing every component involved, following many service manuals and advice, both in cold and hot conditions ( knowing the nature of electronics, fine when cold crap when hot sort of thing ) everything checked out, I was pulling my hair out trying to pin the problem down, the car was still being used and I learned to compensate how I drove it with this condition, this went on for 30k miles until someone asked me if I checked the crank position sensor down by the crank shaft pulley ( GM guy ) I knew there was no sensor there, but got me to thinking where did Honda put this, well obviously I found it was contained in the distributor and not independently serviceable, that the entire distributor assembly had to be changed, while I had no definite proof this was my problem and with Honda wanting $700+ at the time for a new dizzy I took a chance and bought a salvage yard pulled dizzy off another 93 delsol, installed on my delsol and ran like new again, that was the problem all that time, messed with me as the problem never caused a CEL or threw any error codes obviously. Ok so I have been running great now for the last 2 or 3 years, and two weeks ago I started experiencing the same stutter/miss at low rpm under a load, again no CEL, but I am thinking ok I know the problem and I will just get a new dizzy this time Not Honda supplied but went with a Cardone Select which many have told me have been great for them, installed the new dizzy one night, set my timing etc so I would be ready to drive to work in the morning. First 5 miles went pretty well but detected a slight stutter. 10 miles it was getting pretty obvious, 20 miles I was getting concerned because it was worse than I had ever experienced before, 45 miles and at work it was running on 3 cylinders steady. Took my chances after work started it, it seemed fine for a moment then started missing full time, I chugged on home on 3 cylinders for 45 miles. Thought I got bad (new) distributor so had parts house order and exchange unit, when it came in I installed etc and still running on 3 cylinders. getting ignition spark to all 4 cylinders, timing is right on the money. So shut down and pulled my spark plugs and found #1 to be a bit dark and the other 3 cylinders all bright and clean burning humm ( did I burn a valve ?? ) had to go out and buy a proper compression tester since my old one would reach down that hole. (Now for the record this engine is just shy of having 250k miles on it) cylinder compression ranges from 185 to 190 pretty close % I think, so this dismisses the notion of a burned valve etc and have good compression. So now I think I am narrowing it down, while at operating temp I am letting this run while its running obviously on 3 cylinders I start pulling fuel injector connections and obvious big drop in rpm when I do on cylinders 2,3,4 but no effect when I pull injector connection on #1 cylinder, yet if I do the stethoscope thing they all are clicking, and while I have not found the resistance specs on the injectors themselves, I tested all of them and they all were within close range of each other 11.9 to 12.2 ohms, the voltage at the connectors was consistent for each checked while running at 13.3 volts ( I thought this was pulsed ? ) or is to fast for me to notice by this method, but yet pull the connector at #1 injector while running ( on 3 cylinders obviously) and no effect when #1 is disconnected. So even though resistance is the same as the others and I hear clicking is this injector bad ( clogged nozzle what?)

If this is definitely an injector issue is it critical ( as I read and is suggested ) to replace them all as a set! these damn things are expensive ! I can understand replaced O - rings that have been disturbed etc and I understand replacing one may have a different tolerance than the others, but if I am going to shell out that kind of money I need to be sure the injector is the likely culprit or should I be looking elsewhere upstream more.

I am leery in this area as I have absolutely no experience with injector issues, these are original to the car when it was new which now is 20 years old with 250k miles on it, what is the life expectancy of a fuel injector, am I on the right track which my suspicions here or should I be looking elsewhere on this delsol, obviously it is not a distributor issue this time. Although I did the compression check to be sure, it seemed obvious my problem is electronic related as so far when I first start it and its cold it runs at high speed idle of course and seems smooth, but when it warmed up and drops to normal idle then its obvious the 1 cylinder starts dropping out, and I have sat and watched this thing run when warm chugging along on 3 cylinders then like someone turned a switch on the forth cylinder will kick in for a moment then drop out again lie a switch was turned off. So based on my injector connecter pulling and noting no change in rpm on #1 cylinder is it reasonable to assume I have an injector problem, since I know I am getting ignition spark to it and compression test shows good. Sorry to be long winded but I wanted to thorough in my experience with this issue.