Non-starter
Thread Starter
Intermediate
Joined: Dec 2004
Posts: 27
Likes: 0
Non-starter
My 1989 six-speed coupe is very hard to start and has sometimes even shut off while driving. When it does start it seems to run okay. Sometimes it will start, sometimes it won't. So far, my mechanic has checked the fuel pressure, tried a new distributor and. checked back pressure. All have checked out okay. The car gave us a code eight months ago for a bad mass airflow sensor which has since been replaced. It is giving us no codes now. He suspects the mass airflow sensor and/or possible the computer (the computer has recently been replaced with a used unit). Someone else told me that carbon deposits on the valves may be the culprit. Has anyone else had similar problems?
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Engines need spark (and at the right time), fuel and air (and in the correct ratio) to start and run. When it won't start, check for spark and timing with your timing light. Put a fuel pressure gauge on the fuel rail and see if the pressure is correct and if when turning the key off, the pressure holds up. If it drops rapidly you may have leaky injectors. Next, connect a noid light (commercial light for testing injector drivers), or a low power 12v lamp like a 194 lamp across an injector plug and see if it pulses when you crank, this will tell you if the injectors are being exercised by the ECM. Also, don't forget to see if there are any stored error codes. Last, unplug the MAF and try to start it, if it starts, you may have a bad MAF.
