Sounds like a bad ignition module
located just under the airbox on the 24V car, there are two of these, and if one is failing, or the connection to it is dodgy, gives exactly the symptom you describe. I would check the connections there first, clean them up, etc and then swap the connectors to see if the problem moves (module dodgy) or stays on the same cylinder (wiring) -- also check the big circular connector and clean that up too
74 GTV with 10548's and Ingram pump --speedo been around at least twice -- needs new oil rings!
1995 LS Q runners Auto Green/tan 216K 100% LCD
1995 LS 5 speed Green /tan 45K Q runners squadra chip 100 % LCD!
Misc parts laying around for 24V and 2Liter!
2004 Tacoma 4 door TRD (wifes car/kid hauler)- 156K
Mission Vsi, Mission Mod 2, - 20+ years of hockey on these!
radio flyer- rusty from disuse!