mazda mx3 I'm stumped

1993 MAZDA MX3
200,000 MILES • 4 CYL • FWD • MANUAL
Avatar
POOCH
  • MEMBER
  • 2 POSTS
1993 mazda mx3 4 cyl, lots of incomplete combustion on a cold start. makes a big white cloud. not coolant or oil, smells like the exhaust from a cold engine, just lots of it. just changed head gasket, no improvement. injectors cleaned & tested, o2 sensor replaced, plugs, wires, cap, & rotor replaced. what could it be? also, stumbling or surging under acceleration.
Nov 13, 2010 at 11:22 PM
Advertisement
Avatar
JACOBANDNICKOLAS
  • ✓Experienced Mechanic
  • 110,236 POSTS
Have you checked the fuel pressure regulator? Also, are you certain it isn't coolant. I realize you replaced the head gasket, but the head could be warped. Finally, have you checked the temp sensor? It tells the computer how rich or lean the fuel mixture should be based on coolant temp and ambient temp.

Let me know.
Nov 13, 2010 at 11:25 PM
Avatar
RASMATAZ
  • ✓Experienced Mechanic
  • 75,992 POSTS
Pull the oil dipstick and smell it for gas-if it is- check the injectors and FPR if its leaking if not Try replacing the PCV valve and inspect the crankcase ventilation system
Nov 13, 2010 at 11:29 PM
Avatar
POOCH
  • MEMBER
  • 2 POSTS
engine's not losing any coolant at all. temp. sensor checked out ok, but maybe it's intermittent. sounds like I'll look at the fuel pressure. keep the ideas coming!
Nov 14, 2010 at 9:06 AM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.