If my car sits for more than a day or two, it's almost impossible to start. Cranks fine and tries to fire, but just won't make it. I've learned that if I prime the fuel pump a few times by turning the key and then back off, that helps. Once it starts, it runs great.

It's not holding fuel pressure over night... and it's getting worse. I used to be able to let it sit for almost a week, now 24 hours is the max. And now, even priming the pump like 10 times doesn't seem to help much.

If the pump was weak, wouldn't that affect the car while it was running, too? Any ideas here?

 

leaky injectors maybe?

 

Get a fuel pressure gauge on there. If you're reading proper fuel pressure with the fuel pump primed, unplug the vacuum line going to the fuel pressure regulator and see if there's any fuel leaking from there. If not, take your fuel rail out and prime the pump and see if the injectors are leaking.

Oh and change your fuel filter for good measure if it hasn't been changed recently.

 

the title of this thread made me LOL

first off, try turning on the pump and then checking if you have fuel pressure at the rails. if you do its might be an injector problem.

it sounds like faulty fuel pressure regulator, its not a huge job to fix. it happened to my friends lt1.

when you crank it does it like slowly come to life? like something with a gigantic cam or something? thats what his car did. id replace the regulator and see if that does it.

 

Now it won't start at all...

When I used to be able to get it to start after sitting a few days, it would take a few seconds to "come to life." Not sure how it could be a leaky injector since priming the pump multiple times doesn't help any more. The fuel filter has only about 5K on it.

I'm going to check the regulator first... if it turns out to be the fuel pump I'm going to have it towed to the (only) mechanic I trust. I'm just not up for dropping the tank (or cutting an access panel) myself.

Thanks for the ideas.

 

If a(n) injector was leaking, that is dripping fuel into a cylinder, wouldn't priming it make it flood a cylinder even worse?

However one cylinder down would not keep the engine from running. To me it sounds as though you have fouled at least 3 plugs and now it won't start for lack of fire. You should be removing plugs and looking at the condition of each one.

When you go to the mechanic, get ready to grab your ankles.

 

Could also try putting your foot to the floor to get the car into flood recovery mode might narrow it down some more.

 

I've tried the flood recovery mode and it does seem to help after I've been trying for a while.

My best results seem to be to spray some "starting fluid" thru the IAT hole before I start to crank it for the first time. I may go out there later today and try that again.

As for my mechanic, yes, we've already talked about how far I should bend over and what kind of lube to bring. I know it's not going to be pretty.

 

Check your TPS. I had the same problem a few weeks ago. My car would start with starting fluid but not on its own. I checked fuel pressure and pulled plugs looking for spark...all of which were working. Turned out my TPS was in flood mode and wouldn't let the car spray fuel at startup.

 

I have come to love that hobby too. Pop out the fuel rail and injectors and see if the injectors leak. Change the fuel filter too.

 

Usually the check ball in the fuel pump from the symptoms you posted.

Solution: Get a new fuel pump.

 

^ I'm with Grip on this.^

 

ok so if my pressure drops over night then something is wrong?? I thought this was usual for the fuel pressure to slowly fall (when not on!) my car runs fine and starts fine, has great fuel pressure when turned on but it does leak down overnight never thought anything about it till I read this post. feel free to enlighten me!

 

If your car starts fine and runs fine then IMO there is no problem (you want to trade cars with me? )

 

Having the same problem with my wife's LT-1. I changed the plugs and they looked good. I put a fuel pressure guage on and when you turn the key the pump primes it to 40 PSI+, but as soon as the pump shuts off it begins to rapidly bleed down I know what you're thinkin......but could it be the regulator instead of the pump Otherwise, I have next weekend planned for me