Problem w/ my 86 Fiero 2.5L

I have an 86 Fiero 4 cyl. Car will start and run for about 10-20 secs. and shut off. When it runs there is also a rough idle. I rebuilt the Fuel Pressure Regulator. Replaced the Idle Air Control Valve. Replaced 02 sensor. Replaced Coolant Temperature sensor. Put new plugs, wires, cap/rotor. New fuel filter. I cleaned up the TBI Injector. All new gaskets. Fuses are all good. Fuel pump relay is good. Fuel pump runs. I took of EGR Valve and cleaned it. EGR looks to work fine. added new gasket. Only thing i can think of left to do is check for a vacuum leak. I am going to use carb/choke cleaner and spray all vacuum hoses and fittings and around air cleaner to see if the rpms go up at all to find leaks. Is that the correct procedure? Any help would be great

After all the stuff you've done and all the parts you've replaced I would start to look to see if you have a vaccum leak . There is a t-fitting that is located by the intake/TBI area that's known to cause headaches . Also check the lines that go to the cannister thats mounted on the drivers side of the car ,check the metal lines as well these can rot out especially if you drive where they use salt on the roads .

Keep us posted as to how you make out .

Galen Smith
Red 85 Sport Coupe
Founder of Suncoast Fiero Club
Florida Fiero Council

I tried loocking for a vacuum leak. and tried a few things. But now I have new problems. The car starts if the coolant temp sensor is unplugged and map sensor unplugged. If i plug in the map sensor while its running it shuts off. the car idles fine, but when i press the pedal it gets sluggish and shuts off. I was told Fieros had a tendancy to have carbon build ups in the throttle body. I have also been told that i need a new ECU. the codes i am getting are :lean exhaust, rich exhaust, Map (high), Map (low). How can i have them at the same time? I am trying a new computer tomorrow. (luckily i work for a parts store, so i have everything i need cheap.) I have an appointment with a shop on friday to have my car put on a machine to find out whats wrong with it. But i'd rather drive it to the shop than have to tow it. I'll try these things and see if i have any luck.

I don't think its the ECU . Your confussing the ECU when you unplug the MAP and Coolant Temp . Sensor , thats why your getting the crazy readings .

If I had to bet what is wrong with the car I would go with a bad MAP sensor . Let me know how you make out .

Galen Smith
Red 85 Sport Coupe
Founder of Suncoast Club

I have narrowed it down to distributer. i replaced the control module and pick-up coil. it still won't start. it needs to be timed. but now i have great fuel pressure. i think the pickup was my problem all along. thanks for any responses i received.