94 3.1L rough start when cold /hard start when hot

[bocephus]

i purchased a 94 beretta with a couple problems. one of them being the way the engine starts when cold, and when hot. here are my scenarios. if anyone can shed some light onto my situation, that would be great. also, i will add that i was suggested to replace the fuel pressure regulator. i did that, and nothing changed.


cold start (engine at ambient temp) - engine turns over fine and will stay running after a short burp of the starter. however, the engine runs rough and low on RPM for the first 3 seconds. it quickly comes out of the low RPM stage, jumps to a high idle at 1500 RPM, and then a few seconds later it settles into a normal idle speed with the engine running smoothly.


hot start (engine 125+) - engine turns over fine, however i need to crank the starter for 4-5 seconds in order to keep the engine running. if i let off early, the engine will not stay running. when i let off the starter (after 4-5 seconds), the engine will stay running, and idle smoothly.

[neophile_17]

Hello,

The high idle for a cold engine is normal although 1500 might be a little high. First thing to do would be check for vacuum leaks. After that I would look at a leaky or sticky fuel injector. Do you have somewhere close by that can clean them cheap because it might be worth trying if you do. Good luck!

Sam