Question-------------------------
Followup To
Question -
Okay heres the situation I have a 1993 3000gt sl non turbo automatic transmission
I just swapped out a bad motor (low compression) with a good one. The only problem is now when i start the car it starts right up and dies after 3 sec. the car starts every time and dies every time in abot 3 to 4 seconds. could it be a bad oxygen sensor ? I have never had a problem like this and for the life of me I can not figure out what the deal is. please throw me some ideas
thank you
Answer -
Rob,
There are a few possibilites that can be occuring. A bad oxygen sensor would cause poor gas mileage, and you'd see plenty of dark exhaust smoke, but it shouldn't cause your car to stop idling. First, make sure all your ignition components test out good; ignition coil, spark plugs, plug wires, power transformer, and even your alternator and battery.
Next, check your fuel system; fuel pump, fuel filter, fuel pressure regulartor, and even your fuel injectors. Many times a clogged fuel filter can cause idling and hesitation problems. Also check for any restricted air passages starting from your air filter, all the way to your throttle body and EGR valve. It's possible your idle speed control (ISC) motor is also failing and preventing your engine from idling properly.
Once you checked through all your fuel and ignition components, and if none of them turn out to be the problem, you should have your timing checked. If your car's computer (ECU) is receiving a signal from your cam angle sensor that your timing is off, it will turn off your engine. That may be due to a problem with your cam angle sensor. But typical sensor problems would cause your check engine light to come on.
Now, many of these items are tied into you ECU in some way. And it's possible your ECU is the problem. Read this article for further information:
http://www.90gsx.com/eclipse/cap/caps.htm
If your ECU is malfunctioning, poor starting and strange idling problems are typically the first signs. It can't hurt to check that out.
Good luck!
Thank you for your information. I have checked all the ignition and fuel components as well as air. I pulled the codes on my ecu and found it to be telling me my MAF is bad. I dont understand how it could have been damaged. is there a way to test my MAF and see if its not really my computer thats wrong.
AnswerRob,
Your MAF actually contains a number of sensors; which include your Intake Air Temperature (IAT) sensor and your barometric pressure sensor. If your car's computer senses a problem with one of these sensors, it will trip your check engine light. With other Mitsubishis, there are a series of tests you can perform to check these sensors, but unfortuntately, I don't have a service manual available for a 3000GT. You may find luck searching for an aftermarket service manual, or you can purchase a factory service manual from your local dealership.
Good luck!
