1988 Chevy C1500 4.3 TBI. 180,XXX miles.

Truck takes forever to warm up. Even in warm weather. If it runs any less then 10 mins it stalls out and hesitates real bad. Once ran for 10 mins its not to bad at all but has a real rough idle. 10 mins is a long time to sit in the truck and wait. Can't start it and go in side cause it stalls.
Things I have fixed so far:

New thermos stat.
Flushed coolant system.
Replaced Manifold and throttle body gaskets.
Fuel injectors have a nice cone shaped flow.
Replaced all sensors that showed bad on Diagnostic computer. No more codes show up.
New temp sensor, O2 sensor, map sensor etc.
Full tune up.
Replaced fuel filter.
Truck has a bad exhaust leak.

Could the warm up problem be caused from a bad head gasket? It leaks antifreeze but cant find from ware. No puddles in driveway and all hoses show no leaks.
Just don't want to take motor apart again and replace head gasket if that is not the problem.
I haven't replaced the egr valve yet. Not a cheap part if it does not do anything.

Any help would be greatly appreciated.

 

guess id start by a quick chek for vacum leaks.get it running good and warm and spray some carb cleaner or penetrating oil aroun the intake gasket and anywhere on the intake it could possibly leak.if yu spray on the leak the motor will stumble.then i would do a compression test to make sure each cylinder hole was healthy.where is your exhuast leak at?prob need to get that fixed pretty quick if you can.the next thing would be to go thru the tbi unit. ive seen those get pretty carboned up.its been so long since ive worked on one of them tho i cant offer a lot on that.let us know what yu find.

 

Thanks for your info. I will have to check for vacuum leaks again. They can be tough to pinpoint. I had the tbi off the truck and cleaned it up. The compression test is a good idea. Ill have to get that done asap. Exhaust leak is pretty much everywhere. Haven't had the money to get that fixed due to a recent layoff. Don't want to let it go to long. The warm up problem is what I cant figure out. But I guess with all the little problems combined it creates big problems.

Thanks again I'll keep you posted.