Only Runs for 2 Seconds (Page 1/1)
tgcarls JAN 15, 11:28 AM
Hi Team, I am new to the site and relatively new to Fieros. I have 2 cars presently, the first is a 1984 Fiero Pace Car with 500 cubes of Cadilac. That should be back on the road in the spring. My most recent purchase is a 1986 GT V6 81k miles that has been sitting since 2015. When trying to start it was not getting any fuel, replaced fuel pump and now have 45 psi at rail. However when you start it, the car only runs for about 2 seconds and then dies. I have read it is probably running off the cold weather injector during that period. It does have oil pressure and have I guess confirmed power the rest of the injectors. With that said, is there anything else I may be missing or could it be all 6 injectors are bad? Hate to pull the intake if not the case. I cant imagine all six are bad, that would be a first for me. Last question. Is there a problem with water run off on the rear hatch? I had one spark plug that had completely rust out and shot out of the cylinder. I had to easy out the threads. So when changing the remaining plugs, the adjacent cylinder plug is also rusted out and I cannot get a socket on it. Again never seen this before. Thanks for the help TC
Raydar JAN 15, 12:24 PM
Rusted plugs on the front bank is "a thing". Sounds like you got the full benefit of that little phenomenon. The weather strip at the front edge of the decklid was likely removed during the "recall" work. You can still buy them, though. They are kind of uncommon, but they're out there.

All six injectors could be bad, but it's kind of surprising, as you said.
Have you verified the fuses? Each bank has a separate fuse. (I believe they are labeled TBI1 and TBI2. Or maybe INJ1 and INJ2. Fuse #5 and Fuse #10. Both 5 amp, tan.) One of those fuses also feeds the EGR solenoid. If the EGR solenoid shorts out, it will take out that fuse, and those three injectors will cease to function.
Note that 12V is present at the injectors at all times. The ECM switches ground to fire the injectors. Also note that they are "batch fire". Not sequential.

Edit - If the ECM is not seeing ignition pulses from the distributor, it won't pulse the injectors.
Make sure all of the connections at the distributor and coil are tight. Also make sure that none of the pins are pushed back into the connector shell(s).

[This message has been edited by Raydar (edited 01-15-2024).]

olejoedad JAN 15, 01:18 PM
Check that you have constant power and ignition power to the ECM.
tgcarls JAN 15, 02:24 PM
Thanks for the heads up on the rusted plugs. The fuses are good, the only one bad was the 25 heater/ac. We checked the ground to the ECU and that was good, we unplugged the injector harness and had a faint pulse when turning over the engine to both banks. I wasnt looking at the test light, but should the light have been on when the key is turned on and then pulse when cranking? Thanks for the help.
Patrick JAN 15, 02:52 PM

quote
Originally posted by tgcarls:

When trying to start it was not getting any fuel, replaced fuel pump and now have 45 psi at rail. However when you start it, the car only runs for about 2 seconds and then dies. I have read it is probably running off the cold weather injector during that period. It does have oil pressure and have I guess confirmed power the rest of the injectors. With that said, is there anything else I may be missing or could it be all 6 injectors are bad?



Probably the easiest way to determine whether fueling is still an issue is to see if the engine will continue to run using starting fluid.
tgcarls JAN 15, 04:14 PM
yes it will stay running on starting fluid.
buddycraigg JAN 15, 06:25 PM

quote
Originally posted by Raydar:
If the EGR solenoid shorts out, it will take out that fuse, and those three injectors will cease to function.



My 85 did that once.
Painfully under powered, but you really didn't notice a misfire because they are every other cylinder in the firing order.


quote
Originally posted by tgcarls:
yes it will stay running on starting fluid.


a couple of the injector connectors are not too bad to get to.
I would test with a noid light.
If you get flashing, and you are sure you have good pressure. then it would have to be the injectors.
tgcarls JAN 15, 07:02 PM
Thank you, we will try it again tonight.
82-T/A [At Work] JAN 15, 07:29 PM

quote
Originally posted by tgcarls:

yes it will stay running on starting fluid.




I didn't see if you mentioned this... but are you getting any computer codes, and have you checked them?