Or just unplug the throttle siwtch and take if for a drive, see if the hiccups go away. You will have some very slight drivability issues with an unplugged throttle switch, (somewhat sluggish response to suddenly flooring it) but if the hiccups go away, you know what to concentrate on.

If it is very hard to start when cold, look into the cold start switch. Very early cars ('70, part of 71?) had computer controlled cold start switches, later ones had simpler electrically controlled switches. Basically, in either case the cold start injector needs to fire when the engine is cold and the starter is cranking. If it doesn't, it gets hard to start.

If it has trouble idling and running after started up, but still cold, there are two things to look at.
1) The idle air bypass thermo-whatever (it probaby has some fancy name). This is a temerature controlled air valve on the side of the head (front,right hand side) connected to the intake manifold with 2 good sized hoses (about an inch in diameter, +/-). The function of this is to allow more air into the engine when it is cold, to increase the idle speed. These are almost always in poor operating shape now that they are 35 years old. They just simply stick, either open or shut. If they stick open, typically you either pull off one of the hoses and plug it, or adjust the 'real' idle air valve down to compensate. If they stick shut, or it was open and you plugged it, the idle will be too low when it was cold. All this really means is that you have to keep your foot on the pedal while it is warming up, or it will likely stall. Or you try and track down a working unit. Or just put up with the minor inconvenience of needing to press that pedal a little bit on cold mornings.

2) Coolant Temp Sensor - this is the small electrical sensor srewed in the side of the head, very close to the idle air valve. It has the important job of telling the computer when the engine is cold, and the computer will richen the mixture considerably. When these fail they tend to either fail in either the cold or hot readings. If stuck on cold, the mixture will stay rich all the time, and the car will run a bit funny, and start useing a LOT more fuel than it should. If it fails 'hot', then the engine will be very, very cranky when cold, sputtering, coughing, stalling, as the mixture is too lean. You need to get a multimeter and read the resistance when cold, and again when hot. It should have high resistance 1500 - 2500 ohms when cold, and only 100 ohms (+/-) when hot. I always tend to check these resistances at the computer, so I test the wiring as well, you need a wiring diagram to tell which pairs of contacts to test on the big plug.


Here's a good D-Jet troubleshooting link: http://members.rennlist.com/pbanders/djetparts.htm#troubleshoot
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I'm JohnMc, and I approved this message.