1991 2.5L flooding out

I've got a 2.5L with 170k on it, and I have had a problem develop. In the morning, unless I let it warm up for about 10 minutes, it will start to flood out after warming up while on the road. Does anyone have any ideas? I've got newer plugs and wires, along with a newer coil, recently replaced my fuel injector and filter. No service engine light.

Also, I forgot to mention the biggest bugger of the whole deal. This ONLY happens first thing when I leave for school in the morning. I drive up to a vocational program and my truck sits for 45min and it always runs fine after that for the rest of the day. Even after sitting in the school parking lot or 6 hours the issue doesn't come back up that evening.

I would check the temperature sensor and see if it is scaled up on the coolant side. If you have an ohm meter check the ohms and ohm a new one at a parts store. They need to both be appx the same temperature.

Sounds like a tuneup is in order.

Does it use a cap and rotor?

Just replaced the temp sensor this past spring. It would be nice if a tuneup would take care of this, but I have went through a tune up over the course of the summer.

I was wondering if this could be an issue with the computer--since it only occurs first thing in the morning, and once the air/fuel misture control is relegated to the computer is when this takes place. Yet it only takes place first thing, and doesn't take place if it switches to the other system while in park without an issue. It only happens when I don't let it warm up for about 10 minutes, and only first thing in the morning.

It might not be flooding, it might just not have enough spark.

Check your coil connections and spark when it is cold.

It appears to happen when it changes loops. At this point the oxygen sensor should be leaning out the system. Normally an oxygen sensor will fail and lean out a system. I've had a cracked exhaust manifold and the oxygen sensor was telling the computer it was running lean but was very rich. I would look for cracks and spray around the intake with carb cleaner checking for vacuum leaks.

The problem doesn't happen when it is cold. Let me better explain how it occurs, and maybe that will help you out.

Normally always occurs at about the same place in my drive every morning, as I apply a little more throttle to make it up a hill (running at about 60mph, in OD, but the speed doesnt make a difference) and it sputters and misses, and if I really get on it it goes away. But it will do this the rest of the way, and some days it gets so bad it just wants to load up and die, but other days it really doesn't get that much worse as long as I milk the throttle. And as I said, this ONLY occurs on that first drive in the morning. After it sits and cools off for 45minutes and I head to school it runs like a champ, and after I leave school 6 hours later it runs like a champ no matter where I go or how far it is. The outside temperatures also haven't changed the impact of this problem.

Well, my exhaust system is shitty. The cat. convertor is out and there is a leak there, but I also have a leak at the donut gasket. We tried to fix that earlier this summer but we could not get it to reseat properly.

EDIT: Also should mention, I am not getting any worse fuel economy since this started occuring. 24mpg and holding strong.

I thought about your problem and it is identical to symptoms people had when the started using silicon. Before it was approved for oxygen sensors it took many out. I think your oxygen sensor won't get the fuel mixture rich enough the fuel mixture is to lean until the car is warm. A common problem to check this pull the air cleaner and when it is doing this gun the engine if it stumbles spray starting fluid in the throttle body if it immediately revs up you are to lean. I would go to a scrap yard that will let you look and try to find one that was recently replaced.
I had a tester and could watch what was happening and the mixture was definately to lean.

I may give that a try, thanks. The thing I just do not understand is the fact it only happens first thing in the morning, and NEVER again throughout the day.

I think it has to do with internal engine temperature. I think if you went to Florida it would go away. If you drove 500 miles north it would happen much more often. If you have ever driven a tractor with a manual choke it needs much more in the morning. In the afternoon after being driven in the morning it would need much less.
Any way you need to be certain if it is running lean or rich. As the causes are much different.
If the engine is stumbling when gunned and you spray starting fluid if it smooths out it is running lean. If it stalls or stumbles worse it is running rich.
An oxygen sensor is a big cause of a lean engine that runs fine the rest of the day. If you go to a shop with a scanner they can monitor the voltage of the oxygen scanner.
A good used oxygen sensor is cheaper.

Well I have a new dist cap to put on and I will let you all know how that goes. I also may check out my thermostat as well, because my temps NEVER get above 170-180, especially that early in the morning.

Well I have a new dist cap to put on and I will let you all know how that goes. I also may check out my thermostat as well, because my temps NEVER get above 170-180, especially that early in the morning.

You change the cap and the rotor.

Not just the cap.

I know, was lazy and didn't type that. Well, got that done tonight, and I have a strong feeling that will take care of my issues. The button in the cap that holds the rotor in place was gone, and there was good deal of buildup on the posts, and some residue from water inside. Kind of surprsing since we had it off this past summer and cleaned it all up when we changed the coil. Either way, took it for a test drive and it is runnnig very smooth. Will get a full road test tommorow.

I also stuck some carbon sealant around the edge of the dist cap to try and keep moisture out, as well.

A lot of new caps have a vent on top.

This one didn't, which doesn't hurt my feelings any since they put the bastard down there on the bottom of the motor. I would rather it have nothing in it whatsoever to make any risk of water getting in it.

So, the '91 S10 had the 2.5L Iron Duke engine option? I have one in a Cutlass turned the wrong way but still a most cool motor as long as the distributor module holds up. Gotta keep the coolant right in it too.
Did they put that motor in Blazer's too?

I also stuck some carbon sealant around the edge of the dist cap to try and keep moisture out, as well.

Don't do that. You want to let it breathe. Remove the sealant or you will ruin your new cap and rotor in under 6 months.