88 GTA with tpi. This problem cropped up about 2 months ago. It used to be I could let the car sit for over a month, and it would start right up.

Now I can only let it sit for 2 weeks, after that, I have to crank it 5 or 6 times before I even get a cough from a cylinder. Then it runs normally. I also add a few 'key ons' between cranking.

To test it, I let it sit for 8 days, then put a fuel pump gauge on it, it read zero, I think, and one 'key on' pumped it up to 42 psi, then it idled at 38 after I started it, ran fine. Pressure bled down to zero after 24 hours, but that is normal, as far as I know.

I'm no fuel system expert, but it sounds to me like after just a few days, the actual level of the gas in the lines has dropped somewhat, but is near enough to the actual injectors, that one key on is enough to pump gas all the way up to the 'normal' level, ie, right up to the injectors.

But after 2 weeks, the gas level has dropped so much (by leaking, evaporating, leaking back into tank somehow?) that the multiple crankings and 'key ons' are needed just to get the gas back to the injectors. Does that make sense?

I haven't actually tested the initial 'key on' fuel pressure after 3 weeks sitting, but am assuming it would take several key ons just to get the fuel up to the fuel rail, and get any reading above . Just a guess.

The internet tells me it could be the check valve on the fuel pump (A/C Delco, only a few years old, and less than 200 miles on it), could be the fuel pressure regulator leaking gas back to the tank, or a leaking fuel injector.

Ideas?

Thanks

 

Did the internet tell you to check fuel pressure?

 

Probably, but I did my testing before asking the internet.

 

OK, here's a question I haven't found an answer to yet :

Assuming my gas has drained all the way downhill to the pump, how many 'key ons' or engine cranks does it take to get gas up from the fuel pump in the tank, through dry lines, into the fuel injectors?

As I said before, it takes about 6 'key ons' just get a cylinder to fire.

 

your battery could also be a bit low after 3 weeks. I have no issues starting the car right away after long periods of time, but I do keep it on a battery tender. One key and let the pump, well pump, then turn key and it usually wants to starts right up. that said, I don't let it. I like to crank the motor a few times, get some oil into the upper chambers before letting her fire up. so if it wants to start immediately, I turn the key off, and start over. its all about the oil !

boy, thats a bit hard to read. oh well, hopefully you get the idea. have you checked your fuel tank vent valve that is under the tank? those often crack after all these years. not sure if it would have anything at all to do with it, but always good to have all systems working 100%

 

If you hold the pedal to the floor, it will crank and not start until your foot comes off the pedal. Easy Button.

 

Liquid Blue, pretty color on your car !

Yes, if I let it go too long, the battery gets low and it cranks slowly.

Will check the fuel tank vent valve.

Thanks for responding!

 

Interesting. what is the reason?

 

"Clear Flood Mode"....software in the ECM.