1995 sl500 starts fine. warns up it runs rough, stalls and backfires.

run the fault codes
could be a injector problem , low fuel or ignition control module problem

Sounds like it is slightly out of time.

hi Jhlightcap.

The Common Problem: Rough Running Engine

A properly-operating engine should run smoothly and without excess noise. If your engine starts operating in a manner that gives you the perception of "running rough", it is likely due to a handful of common causes. A mechanic would investigate these common causes first in order to rule out a simple explanation for the engine's unsatisfactory operation.
The common causes for rough running in an engine are:

• Engine miss
• Vacuum leak
• Dirty fuel injectors
• Carburetor problems
• EGR valve
• Ignition coil
• Spark plug wires
• have a look at this link.

Rough Running Engine James on Engines 2

it could be as simple as your spark plugs, they may need to be checked for proper gaping and also check to make sure plugs are installed properly, could also be your timing might be off, could also be the throttle position sensor, these could all be effecting the fuel to air ratio, I would start with the easiest problem 1st......hope this was of some use to you.....

The first thing to check is the ignition timing then the spark plug gaps. There are specific settings/size for the above and must be correct for the car to run smoothly.

Repair your vehicle right away. Just click on the link I attached 1995 2000 Toyota Tacoma Service Repair Manual

Check the distributor caps and rotors (it has two).

EGR valve stuck or not working clean or replace

get a couple bottles of gas line antifreeze .. if you don't already use it and add it to the gas.

Robert

P.S. in minus 40 i don't even get out of bed... minus 23 here last nite... isn't winter grand

I just went through lots of troubleshooting and expense on my 1996. Whenever I would lift my foot off the accelerator and was below about 30 mph, the rpm's would starts jumping around and sometimes it would stall. If I gave it a little gas (accelerator), I could sometimes keep it running. It also backfired once in a while. Starts right back up. Also, if I let it idle while in part, it would die after 1-2 minutes.

I ended up finding a hole in the fuel regulator. About a ~$70 part if you get an AC Delco, but very simple to change.