i have a 1990 formula and i was driving down the street when the car starting jerking( it would accelerate and then slow down by itself) so i pulled over to see what was wrong and then when i pulled over the car shut off by itself. the car then wouldnt start again. i eventually got the car home and tried to figure out what had happened. i dont know too much about cars but my dad is helping me too and he cant figure out the problem either. the fuel pump and the relay are both working fine. we bought some starting fluid and used it and the car would start but then die after about 3 seconds. can someone please help me out? thanks

 

you need to get a fuel pressure gauge and hook it up to the fail rail the pump can run but if you don't have 45-55 psi it won't run

 

43.5 is the stock pressure and it will run with a little less just not that well.
Check the injector fuse(s) and them use an ohm meter to test the injectors.
1 real bad injector can take the whole thing down.

 

ok well me and my dad have been working on the car but still no luck. we tested the fuel pressure and everything is good. my dads been replacing other lil things too and seeing if it will work but so far, nothing. we havent tried the injectors yet but he thinks thats it might be the fuel regulator. can this be the problem?

 

If the fuel pressure is correct, and there isn't fuel in the FPR vacuum line, then it isn't the fuel pressure regulator.

The '91s used Multec injectors, which by now (age wise) are failing left and right. You mentioned being able to spray fuel in to the TB and the car runs. OK, it is a fuel delivery issue.

Back to the injectors. Measure the resistance of each injector. Any that are under 12 ohms are bad. If you have ones in the 2-4 ohm range that prevents the ECM from firing any of the others. Boom, car won't run. In this case, or in the case of having ANY injector under 12 ohms, install a set of FMS/Bosch 22 #/hr injectors.

RBob.

 

I just replaced the MAF again. Car would start but would not accelerate past idle. When it went bad 4 months ago it just ran terrible, but i was able to limp home. Too bad they are so expensive, to have a spare lying around.

 

try and igntion module i have seen them cause a similar problem