leiniedude

Hi all, Having starting problems with my 1999 Grand Cherokee, 177K, 4.0 motor. I have spent a couple of hours researching threads here with no success. So I thought I would ask for help. My GC will start right up after sitting overnight and she runs really good. If I drive a short or long time and shut her off she takes three start attempts to get her started again. Always three tries. I have done the poor mans prime with no luck. I can here the fuel pump spin but no start. Unusual to me that the poor mans prime will not work but by spinning the motor over she starts. I have replaced the fuel filter/check valve that is mounted in front of the fuel tank. I had my fuel lines repaired as they had rusted coming off the tank two months ago. I have had my FLAPS store look for codes and nothing comes up. This has been going on for a month and will always start on the third try. I have owned Jeeps since my 1976 CJ7 and am embarrassed with the starting procedure!I am stumped! I am looking for some heavy hitters to help me out. Thanks for ANY ADVICE, Mike.

dave1123

Have you checked the actual fuel pressure when it fails to start? Just for Giggles, try opening the fuel cap when it doesn't start to see if the tank is sucking a vacuum. You could have a clogged vent line that bleeds air into it overnight. I suspect this because of your rusted fuel lines.

leiniedude

Hi Dave, thanks for the reply. Not sure on the fuel cap advice ? Remove the cap and cover the filler neck with my hand while someone tries to start it ? I did put a pressure gauge on it about a month ago. I am not sure if it was working correct. I was in the recommended range of 44 to 54 PSI. When I turned it off the, pressure dropped like a rock. I am going to town today and am going to get another gauge and try again. With the planting going on now its hard to stay on it. thanks again, Mike.

dave1123

Okay, you're loosing fuel pressure either thru a bad check valve in the fuel filter (which contains the pressure regulator) or a leaking injector. A bad injector will usually bleed down slowly where a check valve will be quick. The first thing I would do is replace the fuel filter. If that doesn't fix it, there may be a check valve in the pump, but let's hope not. The fuel pressure should remain overnight to some degree.

What I was saying about the fuel cap was if you get a whoosh of air sucking into the tank when you remove it, the vent may be plugged and not allowing air to replace the drawn off fuel.

Rereading your first post, I see you've already replaced the filter, so the check valve must be in the pump, IF that's the problem. This brings me back to a venting problem. Hmmmmm.....Try running with the cap loose and see if it still doesn't start after driving it awhile. This may set an evap code, but that's easily cleared.

leiniedude

Thanks for more advice Dave. I removed the gas cap while she was running and when stopped . No whoosh, no evap code. I did swap out the fuel pump relay as I am running low on what to do. No change. At this point if you told me to loosen the cap,open the hood and drive down the interstate I might just try it. I slid under the tank to see if the new check valve might be cracked or leaking. I could not get under far enough to see anything. But I could smell gas while I was under there. I always park her in the garage and never have seen a drip on the floor, well, not from gas anyway. With the new fuel pressure gauge on it runs at 52 PSI. and still drops like a rock when I shut her down. If there was a leak in the line I would think there would be enough fuel draining back to leave a mark. Maybe the new check valve was bad. I can't get under far enough to really see much. I am going to take it to my buddy's house and put it on his lift. With some luck, maybe spot a bad fuel line or filter. I will let you know if I find anything, thanks again, Mike.

leiniedude

Well, I broke down and took the GC to a real mechanic shop. Turns out it was the fuel pump. It was a costly repair, giving new meaning to GRAND Cherokee. Hope this helps someone down the road, thanks for the advice. Take care, Mike.