97 s-10, 2.2 liter, standard shift, 105,400 miles. Had a new timing chain and rebuilt head at 90,000 miles.
On my way to work, going 60 mph on the highway, suddenly I started to loose power, engine was running real rough, and the SES was blinking. I got it home and can hardly even keep it running because it is running so bad. Right before this happened it was running great.
Any ideas where to start looking? Could it be as simple as plugs? Or as bad as the timing chain or head gasket? I live 15 miles from the nearest autozone and I don't think it will make it there to check the engine codes. It acts like it is only hitting on two cylinders. It just seems strange that it happened all at once with no warning.
I don't have a lot of diagnostic tools, so is there anything I can check on my own before I have it towed to a shop?
Any help or suggestions would be appriciated.
Thanks

i would check you oil filter and see if there is any metal shavings.

Did you hear any knocking when you lost power? Any smoke? Sounds like a timing problem or fuel delivery. Check fuel pressure if you can and your timing.

For things you can easily do without tools, I would visually inspect for a bad ignition wire (eg. one that is burnt from touching the exhaust manifold) and for any vacuum hoses or fittings that are broken, cracked or disconnected. Would be nice to have the codes -- it could be something as simple as one of your cylinders not firing due to an ignition problem. When was the last time it had new plugs, wires, cap and rotor? That said, I just spent my entire yesterday tracking down a problem on my 2000 V-6 Blazer where the engine suddenly began to run like total crap like yours did causing a flashing SES. Turns out it was all caused by a hairline cracked/defective insulator on an AC Delco spark plug that I installed about 6 months ago -- a $6.00 problem.

Checking for codes would help point in the right direction.
But the flashing check engine light is telling you it has a miss fire or missing cylinder.
As said check the ign system.
Check for good hot blue spark to all cylinders.

Thanks for your replies,
My first step will be to replace the plugs and work my way up from there. It would be nice if that is the problem but it happened so suddenly and runs so bad that I don't know if that will fix it. My biggest fear is slipped timing or head gasket. It doesn't smoke any when I can get it to run and it made no noise prior to the sudden loss of power and missfire, I was just cruising down the highway. I wish I could check the codes but it will not run good enough to drive.

OK, I went to autozone and got a compression tester. #1 cylinder is 0, #2,3 ,and 4 cylinders are a little over 150. So, do you think my timing chain has slipped? If so, what would have caused it to do that? I was driving down the highway at the time it happened and the chain was just replaced 15,000 miles ago. Could there possibly be another problem other than the timing chain slipping?
Thanks for any help you can give

Ouch. Timing chain would cause loss of compression in more than one cylinder. It's either a burnt valve, bad head gasket or a hole burnt in the piston.

Is there any way to tell if it is the head gasket? Anything I can look for? I figured it was the timing because it wouldn't hardly run. Would one cylinder missing make it run so badly? I bad head gasket would make it a lot easier, and cheaper.

. . . Would one cylinder missing make it run so badly? . . .
On a 4-cylinder with zero compression on a cylinder - Yes. Regardless of whether it's a head gasket, a hole in a piston, a stuck or burnt valve, the head will have to come off. So, you just as well pull the head and see what's what. I vote for a stuck valve.

First thing.
Pull the valve cover and check valve operation.
Stuck valve or bent or stuck push rod or rocker arm
And make sure camshaft is pushing lifters up and down.
Also if you have air put pressure on that cylinder and see where it is leaking.
Back threw intake.
Out tail pipe.
Down into crank case.
Or into coolant system.

Yes a miss in one cylinder can make it run real bad.
A burnt head gasket usually takes out two cylinders side by side.

If you pull the head off get it to a machine shop and have it checked for flatness/warpage and cracks and valves done.
And remember new head bolts and proper torque when installing.
Good luck and let us know how it goes.
Mt

I am in the process of pulling the head off. I have a stupid question though. How do I get the cooling fan off? I can't find a way to hold it while I loosen the big bolt(shaft).
If it is a burnt valve, what would cause that? This head was rebuilt 15,000 miles ago when the timing chain broke.

There is a special water pump hub holding tool that keeps the hub from turning while you loosen the big nut. It's not an expensive tool, and Autozone probably has a loaner.

There are any number of reasons why a valve could fail including weak valve springs, worn valve guides, incorrectly faced valves, incorrectly cut valve seat, incorrect seat width, poor concentricity of the seat to the guide, incorrect fuel mixture, poor oil control, poor quality valves. If it is a burnt valve and you had the head done 15k miles ago, it was essentially either a crappy machine shop job, a low quality replacement valve, or incredibly bad luck.

Got the head off today. As I inspected it, I noticed that the exhaust valve on #1 cylinder had a broken spring. Any idea what would cause that? Anyway, tomorrow I will take it to the shop and have it fixed. Hopefully they can just fix the one bad spring, check the head for warpage, and be good to go.

The valve spring could have been replaced without pulling the head.
But if you have it off have the head complete redone while you have it off.
And remember if one spring is broke it is a goo time to replace all of them.
MT