Help!?!?!

OK, so a few days ago I purchased an 86' Fiero GT Fastback. I met the guy took it for a test drive and everything seems mechanically functional at that time. Car does need alot of work though. So I get on the highway and i'm driving for about 1.2hrs doing 70-75mph and it just dies on me going down the road. I coasted to the shoulder and tried to crank the motor. Nothin... battery was totally dead. Bought a new battery and tried to crank again. YAY!! it turns over but will only stay running for less than a second before it kills itself. Figured it was a fuel delivery problem. So I bought a new fuel filter and while the outgoing was still disconnected i primed the fuel lines. YAY! again because its shoveling gas out. I reconnect all the lines and I also go through the trouble to remove the intake and the fuel rail and clean the injectors. I made sure that all the injectors still worked to. yell at me if you like but I just used 12v battery current to fire the injectors. I also visually inspected the fuel rail and blocked off holes while I blew through them, even ran some pipe cleaners down it. nothing special. But I put everything back together and went to crank again. Same problem, it will run for less than a second then kill itself. I did figure out though that if I feather the throttle I can keep it running, but as soon as I let off or try to engage the car or basically anything that requires me to not continuously feather the throttle it just dies again. I no longer know what to do. please help. ALL IDEAS WELCOME!!!!!!

Could it also have anything to do with compression? i really dont know but was just a thought. its not leaking anywhere under the car or in the engine bay. blown headgasket does not sound like my problem. also the guy i got the car from said he put a stage 2 cooling fan on the radiator and that the thermo that was installed is a 130deg. that sounds way to low since i have heard the fiero runs hot. and another thing, when i was driving the car before it broke down on me inside the car i can hear a pulsing vroom vroom (electrical) and my battery guage is constantly moving back and forth a couple of volts to the rythym of the sound. i would like to stop that, its very annoying. and could that have drained the battery? with the computer constantly thinking its about to overheat so its always running? and when i start it and feather the throttle it sounds mechanically sound other than the revving that im doing to keep it going, no knocks, smoke, or ticks. i cant even tell if its misfireing at all. im very confused because the car ran great and just out of no where died on the highway.

One more thing. Some of your symptoms point to lack of injectors firing (Loss of a ground at the ecm, or the ecm itself).

 

The reason I say this is the cold start injector will allow the engine to fire and then die repeatedly. The other injectors should take over, but it sounds like that is not happening.

 

The injectors have a solid 12V applied to one side of them, and the ecm gounds the other side to fire them. Again, check the 5A fuses going to the injectors, check the injector connector (unlikely) under the intake plenum, check the ecm ground (The ecm can't complete it's circuit if the ground is broken), that kind of thing.

 

There is also a device called a 'noid' light which can be plugged into an injector connector to verify the ecm/injector action.

 

Injectors sould audibly click if you have a automotive stethescope on one at the time. The difficulty with all of these ideas is that the fiero injectors are burried due to a crappy intake plenum design.

 

 

Chay

Check to make sure all the gaskets around the intake/throttle body are in right, you mentioned you took all that apart to get at the injectors, so some may have got pinched or slipped out when you put it all back in.

Also, the electronic whirring sound you hear is most likely the fuel pump.

It is common for the heat activated fan switches to die. The after
market parts we get today suck. So guys just hardwire the fans to run
all the time. Easy fix. Uses up a lot of power for nothing.

Ask me how I know.....:)

Dawg

Sound like its that relay thats screwing up.
i changed mine right a way to an adjustable
one.works great! Get them at the local auto
parts place,you should get rid of that relay.
hope this helps.

http://www.oldairproducts.com/catalog/accessories/24-0100/sw itch-adjustable-radiator-fantemp-p-2750.html