Rough start 1996 SL1 has a rough start stables for about a min. and runs find.Also sometimes really hard to start. I've changed the map,iac sensor and also the coil packs . The initial code was p0341. Cleared it and got p1159. Please what do think it can be?

FUEL FILTER,,IF IT IS OLD-REPLACE!
FUEL PUMP NOT REALLY SUSPECT.....BUT POSSIBLE AS IN A THERMAL SHORTING (AFTER A SHORT TIME)
YOU HAVE TO DETERMINE WHETHER THIS DELAYED STALL ISSUE, IS COMING FROM A FUEL OR ELECTRICAL MALFUNCTION. IE: ELECTRIC CUT OUT...SUDDEN LOSS OF POWER...FUEL ISSUES: ROUGH RU..THEN SHUTS DOWNNING, BUCKING & SURGING
IF YOUR NOT FIXED...JEFF AT: JLGPROP@!YAHOO.COM THE WORX GROUP L.L.C.

run fault codes and look for position sensors --MAP/MAF/VAF sensor problems and fuel /injector faults.

What fault codes showed up in a active scan and memory scan?

You replace sparkplugs,plug wire,tps,map,cap and rotor.Thats good,If the vehicle runs and you come to a stop and it stalls,That is the IAC (Idle air control) you say it ran fine for a week now its acting up, Service the IAC or get it replaced.

i have the same exact problem, i have replaced fuel injectors, idle position sensor, idle air sensor, map sensor, temperature sensor,. the only way i can make mine run ok. not great is unpluging the map electrical connector, and it still has no power if u gas on it but it makes it down the road and smells rich, if u find out let me know what the problem was i really love my truck and hate that it doesnt run right, [email protected]

Check the fuel pressure at the rail assembly, there should be a min of 40 lbs at the rails. Do you have any loss of power under a load? You may have an issue with your o2 sensor that is causing the ecm to send an improper signal to the engine ign/fuel map.

Yes by disconneting the map sensor will drop idle and make run rough, the problem is the idle air control valve or a vacuum leak, try to clean the throtlebody with an old tooth brush and some throtlebody spray cleaner if that doesnt help then try having the iac valve checked the iac valve (Idle air control valve ) if with the engine running listen for a hissing noise that will be a vacuum leak, these are the most common reasons for higher than normal idle. hope this is helpful.

clean throttle body and make sure iac is not plugged up with carbon.

try replacing the throttle position sensor

I have experienced this problem on similar vehicles. You should try and replace the coolant temp sensor. If it is not reading the correct temp to the ecm, it will not get the right fuel map. Also, the cts will not always throw a code.