Older honda civic starting but won't stay running

The car; 1991 Honda Civic Hatch back.

Issue; Car starts but when left to idle quickly dies.

Background; I just recently replaced the valve cover gasket as well as a pierced hose that was leaking coolant. Since then (ABOUT 3 DAYS) the car has taken much longer to start up; i.e. when you turn the key it tries to start from anywhere between 2-8 sec. Before doing work it started up easily and regularly. Has been driving fine for past three days otherwise.

What should I trouble shoot first?

I figure I would check the spark plugs when I get home and make sure they are still seated properly. Besides that, I’m not sure where to start.

I always start with getting all the recommend maintenance caught up. Consider doing the maintenance as something you need to do anyway and it might just fix the problem, but at least it will make looking for it easier.

So look at plugs, wires, fuel and air filters. Open that owner’s manual and get everything listed there up to date.

Your title indicates a different problem than your question, but I assume the question indicates your problem, that the car, since you repaired it, just takes a lot longer to start up and then runs fine. If so, I’d check for a vaccuum leak, since you may have caused one while changing the valve cover gasket. You can check for a leak easily, by spraying starter fluid around the valve covers and various vaccuum lines while the car is running. If there is a leak the car will surge. You may have a line disconnected or loose.

Otherwise I agree with you and Mr. Meehan that you start with the basics. But I also would expect a misfire after you got the car running, and I would not expect the car to run fine once started, if there were a loose plug or if the plugs were just much too old.

I believe in coincidences but they are actually pretty rare. Cause and effect is much more reliable. I would assume that something changed either as a result of the work you did or the reason for the work - the loss of coolant or the loss of oil. If the check engine light ever flashed while you were driving the car or the oil light came on, you might want to do a compression test for each cylinder, and make sure each meets the engine’s specifications.

Which injection system is in that Civic? You can tell by looking behind the motor at the intake manifold. If it’s silvery and cylindrical, it’s MPFI. If it’s black, looks like a little cast iron pan with a lid, and says “PGM-FI” on it, it’s DPFI. The reason I ask is that DPFI motors sometimes had an injector fail, and since the “fuel injection” was actually just getting injected into the throttle body rather than the cylinder (essentially a glorified carburetor) a failure of a fuel injector could lead to problems. It’s not inconceivable that you knocked a wire loose while getting the valve cover off and back on.

Another thing to look at in addition to what the others suggested is the distributor - on those cars, you rotated the distributor back and forth to set the timing, and if you somehow managed to knock it loose, you could get this symptom.

Other things that can cause this include the EACV (air control valve - it’s supposed to regulate the idle speed, but when it gets gunked up it sometimes causes stall conditions like this).

Yes, do check the plugs as well, not only to be sure they’re properly seated, but also properly gapped - - it’s not hard to screw up the gap when you take them out. A gentle tap on the electrode from setting them down can do it.

My guess is that you haa spark plug wire in the wrong location. YOu had to remove ALL of them to do the job so Go over them again and make certain they are on the right plugs.