My wife was complaining of hard starting in the Cherokee (2001) and I was like "What, it's a Cherokee it always starts good". Anyway, when it would sit for a it would require the key on off on drill to start cleanly. That symptom pointed me to check the fuel rail pressure. Running it had 45-50 psi but would quickly loose pressure upon turning the key off. Yep, more than likely flowing back to the tank due to a bad check valve. After consulting a couple of buddies of mine who are auto techs for a living (I used to be) it was a concensus that although this problem was annoying it was not likely to leave the little Jeep on the side of the road.
So now I knew I had some time to shop for a good deal on a new pump assembly. I checked some of the area auto stores and they were $200-$300! And the dealer was $400+, WOW! This lead me to check online and I ended up finding a new one on ebay sold by Global Automotive out of Florida for about $100. I bought the pump off of ebay and I had it within a week or so. When the pump arrived, I installed it which really isn't that tough of a job. I think it took me longer to get all of the gas out of the tank (pumped it out with one of those little purolator pumps) then it did to drop the tank replace the pump. If I had to price out the job to do it for someone I'd probably price it at $300-$500.
Anyway, I got the Global Automotive ebay pump installed and started up the Jeep. The rail pressure tested good at 50 psi and it held pressure over night. I was happy, the wife was happy and all was good. Then about 1000 miles later my wife started complaing that it was starting hard again. This time it was only starting hard if she stopped for a short time like to get gas or a quick stop at the qwikee mart or something. Hmm, seemed like a vapor lock of some sort as if she raised the hood and allowed it to cool off a bit it would start right up.
I got the Jeep home and started the diagnosis. Reading the rail pressure I saw 80-90 psi which clearly showed that the regulator was going nuts. Upon key off and a warm engine I saw the rail pressure rise to 140 psi! DANGER! Not sure what the burst pressure is on these fuel systems is but that is too high. Anyway my diagnosis was that with the higher pressures of the pump (80-90 psi) on key off and the excursion pressure (140 psi) due to the added heat of the engine, upon restart the rail pressure was so high that the injectors could not open causing the no start situation until the engine bay cooled down.
Seeing the eminent danger of the high pressures and not wanting to see the fire that 140psi and 5 gpm on a hot manifold would produce, it was off to the local Checker auto to get a good quality Carter fuel pump assembly to replace the cheap chinese piece of junk sold to me by Global Automotive on ebay
. The Carter pump was $212 at Checker and worth every penny in my eyes. I installed the Carter and it has been working great. I then contacted Global Automotive for a refund and I got the "We're sorry sir, but we don't give refunds, you need to re-read the policy on our ebay page"
. Yep, there it was "No refunds, we'll only replace your piece of junk with another piece of junk". Well, I guess I'm screwed there but I'm not interested in putting my family in danger again with another 140 psi pump.
Anyway, there you have it. My experience with the Cherokee fuel system. Sorry this was so long, but hopefully someone can learn from my experiences and my mistake in buying from
Global Automotive, LLC in Miami FL.
Incidentally, my wife didn't like the word "danger" used to describe the junk pump and decided it was time she got a new car. I guess Global kind of screwed me 2x as now she is driving around in a BMW M5. I kept the Cherokee as well and I drive it now. I drive a 3 series BMW as well but the Cherokee will be a good ride in inclimate weather.