fault codes

[LEMONHEAD <br00206@binghamton.edu>]

My 90 is periodically giving me the "check engine" light.  It only seems to come on 
during periods of extend idling AND only when the engine is fairly warm; gauge reads 
slightly over halfway to "H".  When the light comes on, it will go away after a  
minute or two of normal driving; i.e., once I get out of traffic.  

When I try to dump the codes, the engine dies; that is, I insert a fuse into the top 
of the fuel pump relay, remove it after 4 seconds and the engine slightly revs up a 
bit and then dies.  I can't read the codes if the engine dies.  I was able to 
replicate this every time I tried to read the fault codes.

Anyone else ever seen this?  Engine runs great; there is sometimes a slight miss at 
idle however.  

Chris
1988 90 with fresh plugs, wires, cap, rotor, air filter, O2 sensor, clean ISV, 	
	crankcase breather update, all vacuum leaks fixed, and a sump 
	full of fresh Mobil 1.  Soon to replace: fuel pressure regulator and 
	filter...and (sigh) more than likely the fuel pump as it is starting
	to make some strange buzzing sounds every once in a while...