so i recently bought an '88 firebird with a V6 and AOD trans, i believe TH700R4, but i'm not sure. when i got the car, it started almost immediately, but now that i've been driving it as my daily driver for about 2 weeks, it's progressively taking longer and longer to start it. today it took about 3 seconds to start it where it took less than a second when i bought the car. any ideas on what could be causing this? when i start the car, everything electrical is always off. lights, dome light, stereo, everything but the ignition.

that is issue #1.

issue #2 is that the car has multi port fuel injection, but it acts like it has a carburetor. once the engine starts, i have to hold the accelerator at about 1,000 RPM for a minute or 2, or else the engine will stall out and i have to restart it, where i have to do the same thing until it starts to warm up. once the temperature gauge needle clears the "100", i found that i can drive the car if i quickly back out and get into drive. if i'm too slow, sometimes it'll stall, but usually it's fine once it warms up. once i'm driving, everything is good, but once i shut the car off, even though it'll stay running if it's a warm start, i have to let it idle, maybe rev it once or twice before it'll let me shift into drive without stalling.

any ideas on what could be causing these issues?

 

weak battery and maybe a weak fuel pump.

test battery
check fuel psi if low replace fuel filter and retest
if still low you may need a fuel pump.

you also need a factory service manual from HELM.

 

so a dirty fuel filter could cause the issues i'm having? i remember when i had the oil change done and an inspection done the guy said the filter needed to be replaced, so if that's all it is, that's great, since i don't have the money that a new fuel pump would require.

and the voltmeter is always at or around 13 volts when the car is running, plus the starter sounds strong every time. it's just taken longer to start, just like a carburetor that's been sitting for a day or so. i wonder if the weak fuel filter/fuel pressure may be causing the starting issue?