lepr13665

I have a 2002 Jeep Grand Cherokee limited with a 4.7 L, 70,000 miles on it. It has been hard starting after it sits for 1 to 8 hours. I have to stay on the key for about 5 seconds or push the accelerator pedal to the bottom to start in about 3 seconds. If I try to start it after half an hour or leave the car overnight, it starts fine however, in every start, it always smells raw gas. I put new plugs, fuel pump, fuel filter, battery and still have the problem. Any help will be greatly appreciated. Thanks!
Luis

okcjeeper

Moved to Grand Cherokee techinical area so you will actually get some responses..

RRAM

I have had this with other fuel injected engines. It ussally happened around the time I needed rid of them so never actually found the fix. its basically acting like the engine is cold even when its not and kinda. On carburated engines this was a sign that a choke was giving problems and not coming off. sounds like a case of the engine being flooded. maybe O2 sensor. hopefully someone else will actually know something.

powellp

try changing the distributor cap and rotor.

RRAM

4.7 do not have dist cap and rotor they dn't even have plug wires, they have a coil that sits on top of each plug with wires from the computer

MadMonk

Try this. When you go to start it cold, try turning on the key for about a second before you engage the starter and see if it helps. When cold, my GC takes longer to start if I just engage the starter right away, but if I wait a second after turning on the ignition it starts up fine. I don't know why it works that way (maybe something to do with fuel pressure?). It starts every time without problems when I do that. I'm curious if it works the same way for you.

powellp

Sorry, I should have read the post closer, I assumed it was 4.0

MadMonk

The '99 and up 4.0 engines also have the coil-on-plug type of ignition system (at least mine does anyway).

powellp

okay

Stewhatch

I wonder if you have an air-bubble in your fuel line - close to the motor? It would disappear when it cools, but reappear when the engine gets hot. This typically happens a lot on a carburetted car and not a FI engine since the fuel psi in FI is much higher and normally would eliminate any such bubbles, but it does sound like this is a possibility. I'd look for the fuel line high point under the hood, and bleed out some fuel and cap it before re-attaching it just to be sure.

glosol

OK I am aware this is a very old post, but this just has to be addressed.

Not to be rude, but there is no conceivable way at 30 plus psi of fuel rail pressure for any residual air to be in the line. Its simply not possible. any air in the line would be either pushed through the injectors, but more likely to be sent right back to the fuel tank along with the excess fuel pressure when it leaves the regulator.

If you smell gas it is much more likely that you will have some drippage under the jeep. The reason I say this is any fuel smell means it has somehow escaped the system...thats simple... but at the same 30 plus psi of pressure, assuming there is any leak in fuel lines, it will be coming out at a pretty decent rate.

I have the similar problem in my GC, but no gas smell. One of the above posts said turn key on for a second before trying to crank it over. Great advice, and that would lead me to believe we are talking about a leaking fuel pressure regulator, allowing that 30 psi to run back into the fuel tank. That would be a very real reason it is hard to start if sitting for a while.

ol"blue

You're correct on two counts.
This is an old thread. And a leaking fuel pressure regulator would allow the pressure to bleed off while sitting, causing longer cold cranking times unless the key was cycled first to prime system.
And Welcome to CF.