Howdy! I need some help with my 1988 Formula 350 Firebird. I have had her for under a year and have had this issue with her the whole time I've had her. She will take about 5-10 seconds to start up, but if she sits unused/driven for a day or two, she will crank up instantly. I've checked my starter, I've replaced the battery with a brand new one, and I've installed a new alternator. I do not think it is a fuel pump or fuel filter issue because after she starts up, she runs just fine. Any suggestions on what could be causing this? I would really like to get this issue fixed. Thanks for all the help!

 

Is it fuel injected? Because if it is check for leaky injectors. Sounds like your air fuel ratio may be off when it's warmed up. A warm engine would not need the extra fuel. When it sits and is cold it'd make use of any extra fuel.

 

Its a TPI so I am assuming it is. How do I check for leaky injectors and my air-to-fuel ratio?

 

There's a procedure where you pinch the two fuel lines at the front of the manifold and look at a fuel pressure gauge. It should hold steady. If it doesn't then the fuel is leaking through 1 or some injectors. You can also pull the rail and hold them over a bucket and turn the key to prime them. There should be no leaking from any of them. But the easiest way is to install a fuel pressure gauge on the Shrader valve, turn the key to on. After the pump primes, pinch both lines closed and look at the guage.

 

I had a similar problem with my 88 GTA with TPI fuel injection. Would start up right away when cold. And also when hot. But if you let it cool down to half way down the temp gage ( 140 ?) you would have to jump all over the gas pedal and rev it some to keep it going when you started it, and after 20 seconds of this, it would run fine.

What fixed it was replacing the fuel pump. Don't know why, but that fixed it.

My fuel pressure was borderline low, I think 18 PSI, if I remember right. New pump pressure was way back up to whatever the right number is ( 24 psi ?)

Oh yeah, the car would buck sometimes on acceleration, a classic symptom of low fuel pressure.

Good luck.