Several years ago I had a similar problem... when the car sat over night, it required 4-5 more cranks before starting. That time, it was the fuel pump. Until I replaced the pump, I was able to prime the fuel pump before starting the car once or twice and the problem would go away.

This time, it's a little different... even after priming the car pump several times, the hard start issue is still there. I've also noticed that there is no pressure when I release the Gas Cap after it sits for a while, but does hold pressure after the car is warmed up and and I open the cap. I tried to smell fuel to see if there was a leak.... none near the engine bay... and a little at the rear of the car.

I will be checking the fuel pressure with a gauge in a few days, but I was thinking it may be something as simple as the gas cap needing replacement.

So my question:
If the fuel pump doesn't hold pressure in the lines(ie. bad pump), the fuel and the fuel pressure will drain into the tank with the return line.... however, will the total system still hold some pressure? Would the release of the gas cap still cause a hiss even if the fuel pump is not holding pressure?

I would think it would hold some pressure, as any fuel pressure released back in the tank would stay there unless vented by a bad gas cap or a leaking tank.

What are your thoughts? If this is a leaking cap... it'd sure make my life a lot simpler

 

The tank has a seperate breather valve to relieve pressure and vacuum so the cap has no effect on your flow or lack there of fuel.

If you suspect lack of fuel is the problem, squirt fuel directly in the intake.

I suspect however, you need new plugs.

 

Ignition is not the issue... plugs replaced 2 months ago... and the problem was occuring before. I'm running the LTCC with some good wires... no arching, etc.

As for venting... are you saying that the tank has a breather valve to vent fuel directly to the environment?

It was my understanding that it was a closed system... actually all cars have closed fuel systems to pass emmissions laws. That's why we have non-vented gas caps and that is why they test them to see if they hold pressure. What would be the point of a non-vented cap if pressure is being released somewhere else in the tank?

I would find it hard to believe that... anyone else have any ideas?

 

I had a similar problem where the car wouldn't start and there was no pressure in the lines. The pump would kick on but not build any pressure. Found out it was an injector that stuck open. Pulled all 8, cleaned em out and re installed. Everything worked just fine after that. Try having someone else turn the key on with you being under the hood, if you hear a spraying noise that could be it.

-Pete-

 

Yes, a leaking injector could cause hard starting due to a rich condition. Plus it would cause a loss of pressure in the system. The pressure at the cap and pressure in the lines have a relationship, but you can't judge fuel pressure by what you hear at the cap. You can run with the cap off and still have (and should have) pressure in the lines.

 

I'm having the same problem apparently as you. I have hard cold starts, cranking a lot... I have new fuel filter, new ignition (opti, wires, plugs) AND 2 weeks cleaned injectors! The first few days after the clean it started great but after a while it went back to starting hard... can't belive the injectors got dirty again wtf ???

 

i had similar issues, long cranking, sometimes it would start up and then die, or start up and idle like ***.... the longer it sat the worse it got (to the point it would stall 2-3 time before i could get it to start and run like ***, run it for a mniute, shut it down and restart it)

it turned out to be a leaking intake elbow

i also failed emissions due to this (2.7 nox with allowed 2.5 and 1.5 HC when allowed was .8) and the new elbow is now installed, and i got the car resmogged today and the HC was .30 and the NOx was .13

my car now starts with very short cranks where it used to crank for 5-10 seconds before it would start (even when it did run fine (like if i drove it and parked it for 5 mins then restarted it)

 

Are you saying all this was because of an air intake elbow? The ones coming from the air filter? was it before or after the MAF sensor? Which one exactly? Can you maybe give more details so i can check it?

I also got that thing you said, after cranking for 3-4 seconds it starts in the end and for a while (3-5 seconds) it idles horribly, like it chokes to death, like it had no fuel or something.

Btw, it runs ok after it starts and gets hot (kindof still rough idle but not that bad...), runs fast, revs good...

MORE DETAILS! Thanks

 

after the MAF


heres a pic of my engine before i changed elbows... i mean the one going from the MAF to the TB, the one that curves and has the opti hose on it (little black hose with a blue 90 degree bend piece at the end)



FWIW this is what i replaced it with. I just popped a hole into the rubber coupler that goes between the MAF and the elbow and put the hose there rather than drilling the elbow


http://store.summitracing.com/partde...5&autoview=sku

heres a pic of it installed, i used the same camera phone as i did before but for some reason it didnt come out as well, probably because i had the car in the garage for the second pic whereas the first i think was outside

 

I'm going to have a look into that elbow tomorrow

 

did you find a leak in yours? im not guaranteeing that is your problem, only saying that it was what cured mine.

 

I've looked at it, aroud it, moved it around, doesnt seem to have any cracks or ... holes... i don't know!

How do you test it for leaks ?

 

not sure what they did.. i took it to a shop for diagnostics and thats what they found...i think it was loose on the bottom maybe because thats where the duct tape ended up except for one small spot on the side of the elbow where it meets the TB, but that spot had been like that for at least a few years because once before i changed elbows with a buddy of mine and tried his metal one to see if my misfire problem was related to that, and it ended up that time being due to my cap and rotor, but this time it was definately due to the elbow, and more than likely, to the bottom part of it that attaches to the TB, not the side

 

BTW.... I went out yesterday and primed the pump about 10 times (ignition on-ignition off).

I start the car... and same problem.

So my theory is... if it was a lack of fuel pressure in the line because of a bad pump or bad injector, this would have been resolved by priming it so many times. And if it was a leaking injector... it'd still start faster because (unless all of them were leaking), with 7 injectors working right... it'd catch a lot faster.

I wonder if with a 383 motor, the program needs to be changed for cold starts, or fuel enrichment on cold starts, etc.

Any thoughts anyone?

 

for C Man: Priming the pump isn't any help, starting bad seems to be something random for me really. Sometimes i'm in a hurry to leave i think ah screw it and turn the key right off and it starts incredibly fast, other times i wait like 10 seconds after i turn the key for it to have time and it still starts after 5 seconds cranking. When i had the whole intake + elbows and stuff installed after intake gasket replacement it started perfect the first day. After that started to go bad again, i'm thinking there may actually be a point to the whole "air tight" conduit problem. While you drive you rattle the car a lot, and stuff gets more loose then when you put it together in the first place. So for example, the day i looked around my elbow and moved it around, pushed it in etc, car started instantly. Later that night after a drive, slow again

Also, someone said about fuel smell, when i stop the car after driving a while, when i get out of the car i feel a STRONG smell of fuel coming from the rear wheel direction!!! I'm wondering where that could be from??? The cap is definately sealed tight! Could it be that the pipes from the EVAP canister are blown/rusted or the rubber hoses that connect around there are dead and leaking??? Could something else cause that powerful fuel smell? After a few minutes stopped the smell goes away.