meangreen92

iTrader: (1)

Hi, my 92 350 TPI has been sitting for yrs and since i bought it last month, i have been trying to get her up to par.. I've replaced plugs, wires, distributor, module, cap, rotor, coil(also had one plug with wires ripped going to module-replaced), and some other stuff on motor... I had a scan tool hooked up and on datastream i had no spark advance and it was popping and farting from 1000-2200 rpm, i replaced the dist/ coil b/c i figured the pick up was bad, well now its still running about the same, the timing is about 8 degrees according to the tabs with a timing light, BUT i cant stay hooked up to the ecm, its not giving any data or letting me in... Im thinking im gonna need a new ecm/prom but not sure, was wondering if im missing anything first??

ls six

Get a fuel pressure guage kit (can borrow or rent from most parts stores, be sure it'll fit the TPI port) and if you are doing it by your self place the guage against the window where you can see it from the drivers seat.

Turn the key to the ACC position (just to where the accesories will work, dont start the car) and wait for the fuel pump to prime the rail.

It should run for a few seconds then stop. If the pressure drops after the pump shuts off you need new injectors. This is common for 90-92 TPI cars as they switched brands for the last 3 years.

meangreen92

iTrader: (1)

so pretty much the injectors are just bleeding off and not working correctly?? ill have to check it this week....

ls six

Theres a good chance yeah, mine were way off when I checked the ohm's as well. Even if the pressure dosn't drop it's a good idea to check the resistance too.

meangreen92

iTrader: (1)

ok, well i couldnt fit the fuel pressure checker i had on it, ill prob have to take off the MAP off the intake so i can sneak it in... what ohms should i be at on the injector pulse?? i have a noid tester to see if they are working , but i can hook up a meter too.. ill try by thurs or fri when im off

Saculia

iTrader: (1)

You may have done this already, but did you replace the fuel filter. The pressure bleeding off after the pump shuts down doesn't immediately mean you have leaking injectors. You could have a bad fuel pump check valve and that could be the reason why pressure bleeds down. As long as the pressure is fine when the car is cranking and running you should be fine and don't need to replace the pump if that is your problem.
To check the injectors for leaks, you would have to pressurize the fuel rail. Another sign of leaking injectors is fuel on the spark plugs after the pump primes.
To check the fuel pressure remove the distributor cover and unbolt the map sensor from the intake manifold, but don't disconnect it.
Remove the tube from the vacuum port on the fuel pressure regulator. Turn the key to the on position and observe the pressure. It should rise rapidly to 45-50 psi. Make sure that no fuel is coming from the vacuum port on the fuel pressure regulator.
Reconnect the vacuum line to the FPR and start the car. Fuel pressure should be anywhere between 38 and 43 psi.
Also, this seems like a dumb question, but did you make sure that the connector to the distributor for the electronic spark advance is hooked up.
Set the timing to the numbers on the label under the hood, which is 6* BTDC with the ESC connector at the distributor disconnected.

meangreen92

iTrader: (1)

I have replaced plugs, wires, cap, rotor, module, dist, coil, fuel filter, all due to being ancient and destroyed, all connections are on and tight on the module and the coil... which one is for the esc?? i tried the one that separates and has one plug in inline but that didnt help, ill try tomorrow with the map off to check pressure....

meangreen92

iTrader: (1)

ok checked the fuel pressure.... with key on i got up to 26psi-def not enough... running it got to 32 psi... guess i have to scrape up for a good pump, prob a walbro 255 or something, are all 92 firebird gas tanks the same?? i have a chance to score a good one, and i can clean it out good, set it all up, cause my tank is almost full and kinda crapped out.... thinking about a new sending unit and housing for the pump too... will keep you guys posted....