i have a 1998 sl1 high miles has just started missing /hesitation at around 35-45mph some times then picks back up after working gas pedal then runs fine does not always do it

 

Sounds like it's time for plugs, wires, and coilpacks.

 

have replaced plugs and wires no engine lights or codes how can you check coil pack to see if breaking down

 

considering the complexity of todays fuel injected, computorised engine there are numerable things that you can guess at that might be the problem. The basics are fuel Air and Electicity.
Fuel, a dynamic measure of fuel pressure will tell you if you have that right, I have not figured out how to do that either and drive too so maybe checking/replacing the fuel filter would be a good thing to do. The old if you can blow through it, it is good rule still applies.
Air? How about a dirty air filter. That will catch you by surprise every now and then. It has me, cause things run so maintainence free for so long you forget you need to do something.
Electricity. Well lots of connectors going around. Is anything corroded? Try unplugging and re-plugging stuff like connectors to fuel injectors, spark plug, coils or what ever is the substitute for that. I keep a tube of grease for connetor applications handy and re-lube things before putting them back together. Battery connections, ground connections, things of that nature.
Not too long ago I worked on an old Toyota that was being driven by a retired lady on a budget which translated to if it ain't broke don't spend money on it.
It broke, no money to spend.
It was an ignition problem. When I remove the spark plug wires they came apart in my hands. The distributor cap turned into distributor cap dust. It had to be OEM. (she bought the car new a really long time ago) I could not believe it. Powdered distributor cap. I nver saw one do that before.
It was my birthday present for her. She paid me with Choclate Chip Cookies.

 

unc, pls stay on subject (diagnosis).
I know you're tryin to help but I gotta draw the line at blowing through fuel filters, old Toyotas, and distributor caps.....

----
CP,

1) Have you ever replaced ECTS and connector? When failed this will usually cause an abnormally rich fuel mix which can lead to bogging in specific RPM ranges.

2)Are the wires and plugs OEM ? Stock (NGK) plugs work best. Hope they are not platinum. These ignition systems don't like em.

3)Make sure wires are < 12,000 Ohms
4) Coil test:
disconnect all plug wires from coil towers ---noting which came from where
crank engine while having someone watch the coil towers. Should alternately see a strong spark across each.

Check resistance of each coil pack -- should be 7000 to 10000 Ohms.
_______
You stated high miles -- may want to consider a compression test to get an overall view of the basic health of your engine.....

 

O.K. derf, no more toyotas, the point being though, todays motors will take a lot of deterioration befor operational failures take place and as far as diagnosis goes. If you can blow through a fuel filter, it ain't plugged. No sense in spending money putting one in that isn't needed.

 

1998 saturn missing now has a engine code of miss fire cylinder 2

 

what were results of recommended checks above?
Have you changed anything since last post?

 

went ahead and changed plugs and wires runs fine no miss at all

 

excellent news -- another S car down the road on all 4 cyls