when my car sits it cranks for a good 5-10 seconds before it wants to start. Although if i drive it then turn it off it will start right up. am i not holding fuel pressure? any thoughts appreciated. thanks

-andy

 

More than likely the check valve in the fuel pump is defective and allowing the fuel to drain back to the tank over time. This appears to be the most common failure to fuel pumps in our cars.

Until you fix the problem, to reduce wear on the starter from long cranking, do this. Turn Key On Engine Off for 3 seconds then back off. Cycle power like this for 5 or 6 times. Then finally crank it up. This will confirm the check valve is bad if it starts up quickly.

You can fix it 1 of 2 ways. Either change the fuel pump in the tank or add an inline check valve. The second method will require a small amount of modification to the fuel system.

 

My car has done this pretty much since I've owned it (I'm the second owner). I have not put too much thought/effort into it, since I have always been able to get around it by priming an extra time. I was just talking about this with a coworker at lunch today, and we figured there was a fuel leakback somewhere. I thought maybe an injector was leaking down (not likely) or something to do with the regulator, so I decided to do a quick search of it. What speedygonzales has posted seems to make sense to me. I was not aware of this check valve issue with our fuel pumps.

I have never had key on and back off more than once (that is, I key up until the fuel pump does its prime, key off, then key back on for a prime and then start). The car has never failed to start or left me stranded, but I still wanted to know the culprit. I've been thinking of selling the car and upgrading to an LS1 vert (or a C5), and I'd like to be able to explain it (or fix it) for a potential buyer if I go that route.