I have a '94 Olds Regency 98 that runs rough at idle and often stalls.
When cruising it sounds like the engine wants to cut out but it doesn't.
I've also noticed that when I floor the accelerator it seems to run OK,
but living in the city I don't have many chances to try to know for
sure.

I replaced a vacuum line that runs to the fuel regulator that was
cracked, but it didn't fix the problem. All the other vacuum lines
appear normal.

"KenJr" <kennyjr (AT) NOSPAMatlanticbb (DOT) net> wrote

While that could be several things, I'll mention some that come to mind
right away.

1 - Fuel filter clogged

2 - Spark plug wires and/or bad plugs or not gapped properly

3 - Timing off

4 - EGR valve or plugged PCV valve

5 - Leaking head gasket

6 - Fuel pump not pumping enough fuel

In article <b6nGh.3423$pG.1003 (AT) newsfe19 (DOT) lga>, kguardian (AT) gmail (DOT) com
says...
Update, still running rough. I replaced the spark plugs today and gapped
them to .060, checked the pressure at the injector rail (37 psi),
checked the PCV valve (took a while to find it, but it seems to be
working.

How do you check this EGR valve? On previous cars I could push the
diaphram with my finger to see if it moved freely. This one doesn't
appear to have one that I can see.

"KenJr" <kennyjr (AT) NOSPAMatlanticbb (DOT) net> wrote

I see.... in your case you DON'T have a conventional EGR valve then. You
have a digital or linear EGR valve that is electrically controlled by the
ECM...they don't have diaphragms. In either case, digital or linear, you
need a scan tool to check the valve. You should not try cleaning these types
of EGR with any solvents, etc. You can test the pintle by depressing it with
something soft (ie a piece of wood with some cloth on the end). If the
pintle is sticky or moves roughly it probably needs replaced, but they
aren't cheap so you would want to be sure that, that's the problem before
purchasing another one unless of course the auto store has a good return
policy as in....if it doesn't fix the problem, return the part Anyway....
if you go to http://advanceautoparts.com/ and add your vehicle, then do a
search for EGR, you'll get an idea of what your valve looks like.....

In article <ux0Hh.1931$C_.1085 (AT) newsfe22 (DOT) lga>, kguardian (AT) gmail (DOT) com
says...

I want to thank you for your help. I've concluded this is beyond my
ability to properly troubleshoot and have taken it to a dealer for
repair.

I hate these new cars with all the computerized BS under the hood. I
remember buying an 84 Honda Accord from my brother-in-law for $100
because he said his mechanic said it would cost over $1000 to fix it. It
took me 10 minutes to trace the problem to the carburator and 30 minutes
more to find a bad O-ring. It cost me under a dollar for the O-ring and
the Accord ran great for a number of years before the body rusted away.
The hardest part of the repair was keeping track of the 22 vacuum lines
coming off the darn thing.