1990 Jeep Cherokee Starting Problem

I have a 1990 Jeep Cherokee Laredo with the larger engine option (I forget which it is, currently). I bought it in November with about 160k miles on it.

About a month ago, I went out to start it one morning, and it just refused to start up. It cranked and cranked just fine (not a sluggish crank like you’d hear if the battery were running down), but refused to ever actually start. I tried it for three days (these were all very, very cold days, sub-freezing), with no luck.

A friendly neighbor suggested that the ballast resistor is often to blame for this trouble, so I ordered a new one from the dealer. On the day I went to replace it, which was a warmer day than the previous few, the car started before I even changed the resistor. I replaced it anyway, but had no further starting issues with it for about month.

Until last week, when the problem arose again. It was damp and cool, but not nearly as cold as it had been then. I waited a couple hours, went out to try it again, and as it was turning over, I gave it a little gas and it hesitantly turned over and started. I drove it for another few days with no problems, but this last Wednesday, same problem. It wouldn’t start for about two hours, even with me pumping the accelerator (which I normally do when starting the vehicle). Finally, in a fit of frustration, I jammed on the accelerator after letting it crank for about 5 seconds, and it caught and started, again, very hesitantly.

Additionally, sometimes, lately, when I start the vehicle, it idles very high for a couple seconds before dropping back to its regular idle speed.

I got my oil changed yesterday and asked the guy about it, and he said that it would be tough and expensive for them to try to diagnose it if the problem was only happening intermittently.

Anyone have any ideas?

I should also note that during my emissions inspection at the end of last December, they replaced all my plugs and the plug wiring. They also informed me one of the fuel injectors was bad, but since it passed inspection it didn’t NEED to be replaced. Being on a budget, I haven’t gotten around to having that taken care of.