When start cold, engine light is on solid and running rough. Once I started accelerating the engine light started flashing. Once I got up to highway speed and full temp, the engine light went back to solid and is running smooth, even at idle. Any ideas?

 

First place to start would to get the codes read. Sounds like one/more of your cylinders has a misfire. Get the codes read. You'll have more info to pass along so that someone can help you out.

Mark

 

Most likely a misfire. Get the codes read as marksoftball recommended. If the code confirms this, replace your spark plugs. Nevermind if they're still good, it's a cheap and easy fix and will never hurt. Double check that the gaps are correct on every spark plug. If you're still getting a misfire, start researching how to replace the spider injectors. Only I don't recommend replacing them. Once you get to them, remove the poppet nozzles and spray each one, one at a time, with starter fluid. Also inspect all the fuel lines for cracks and leaks. Gently tap the nozzle on a clean hard surface, spray and tap, spray and tap. Rinse and repeat for all poppet nozzles. Reinstall the poppet nozzles very carefully so they don't get dirty again. Put it all back together and your problem will most likely be gone. Don't forget to torque all intake cover bolts to spec and make sure your gaskets are still clean. If you find one that's damaged, don't chance anything and just replace it. They're cheap and almost always in stock at local auto shops.

 

If you need to go as far as checking each poppet valve the smart thing to do would just get the updated MPI spider unit. The poppet style spider is a poor design flaw and you will have better performance and dependability with the update. Makes no sense to leave this notorious problem part installed. A new Delco unit will have the new injectors not poppets so it is a win win situation. first do all the standard fuel pressure tests and leak down tests. Could ber the fuel pump and ot fuel pressure regulator and again if it is the regulator just do the MPI upgrade and be done with it.