fast_eddy

Ever since the first day I picked this jeep up, it takes several seconds to turn over during the first start of the day -- or if it has been sitting for some time. The battery that it came with was pathetically small and had only around 500 cold-crank amps, so I bought a new one that had 850 or so. I tested the alt and starter, both checked out. Did a full tune up (plugs, wires, air filter, fuel filter, oil change, fuel system cleaner, throttle body cleaner, MAF cleaner) along with some other minor stuff (coolant drain/refill along with temp sender, thermostat, therm. housing). The thing runs/drives like a champ... but I'm hoping I can clear up this cold (not really cold, I'm in FL, but the 1st start of the day) start issue.

I suppose the two possibilities are fuel delivery (a weakened pump or perhaps a faulty fuel pressure sending unit (or some like mechanism)) or an electrical drain is occurring somewhere. The only reason I tend to doubt the latter is that this thing has so few power options (no power options, only an AM/FM, no fogs...).

Any input or experiences with this issue are much appreciated... as well as some advice for what my next steps might be.

THanks!

mike albo

what year,motor,mileage

fast_eddy

Sorry about that:

'98, 4.0, 5-speed with approx. 200K on it....

fast_eddy

Thought I'd update this with what I've found thus far... see if anyone has any ideas.

So I let the jeep sit for 48hrs. This afternoon, I brought out my multimeter and tested the battery: holding strong at 12.65 volts after sitting. Disconnected the terminal and tested for a current draw, 20 miliamps for a moment and then right around zero. No problems there.

Just for an experiment, I turned the key on, let the fuel pump activate, turned it off, and then turned it back to have the fuel pump send fuel again. It started quicker than it has in the past, but ran rough for a minute or so before evening out.

I've heard that some fuel sending device can go on these cherokees and one of the symptoms is having to do this (activate the fuel pump twice). I'm going to start searching for this now, but any help would be appreciated. Other input is valid as well... I may have jumped to conclusions a bit early about the whole fuel delivery hypothesis...

poolguy1995

I have the same problem - living in Southern Arizona I have a hard time calling it a "cold" start though.

I read on here that there is a check valve built into the fuel pump that tends to wear out over time. When the Jeep sits, the fuel slowly flows back into the tank, leaving an empty fuel line. That's why the double try will start it up, the first attempt will re-prime the fuel line, the second will start it normal. I find that if I just turn the key to the on position, and wait for a few seconds before I turn it over, that seems to work as well - the fuel pump will run for about 3 seconds once you turn the key on.

I don't know if that is what you are experiencing, or what years that problem was covering, but its worth a thought.

One fix I had read was to add an in-line check valve as close to the fuel tank as you can. You just can't use a cheap plastic check valve, or the PSI in the fuel line will blow it out.