Hello all trying to fine tune by 1980 242 b21 kjet here. I started working on it a few months ago. Replaced entire cooling system., exhaust, intake, valve cover and throttle body gasket. Cleaned injectors. Washed everything in solevent. New injector seals. New. Coolant sensor alternator, oil pressure sender, engine wiring harness, engine mounts, tranny mount, carrier bearing, you name it, it's. Been replaced. One problem though, now it wont start worth a ****, suspected flooding and has a high yet erractic idle while in neutral / on the clutch. Drives great once it starts. Sometimes I can crank her and crank her with no success other times she fires right up. Idle steady at 1500-2000 rpms. I can adjust the **** on the throttle body, and correct the idle but after revving it bogs downnand wont restart so I have to open the valve up again to get a chance at a restart. Ive got a lot of time and money in this project and I'm going crazy with this little problem!! I'm not thinking head gasket or fuel pump cause it has plenty of power through all gears and compression is 155-170 accross all cylinders....

 

Assuming it ran well before renewing parts, most likely you have disturbed some bad wiring. The 80 is smack in the midst of the years with biodegradable insulation. Too, it sounds as if your warm up regulator (WUR) is not working correctly, either because of failure or poor connections. You can find many of the original Volvo Green books at kjet.org

 

Do you have a fuel pressure test gauge, test light and volt ohm meter?