Cranks, no start, reset key and it starts.

I can't figure out how to search on my phone so sorry if this is a repeat. 1998 Cherokee 4dr sport. Try to start it the first time and it wont, reset the key and try again and it fires right up. I wanna say cps but it has been awhile since I've dealt with it. Thanks in advance.

runs smooth as normal after it starts-- failed fuel pressure check valve in the pump or failed pressure regulator

runs rough after it starts-- leaking injector

would be my guesses

do you hear the pump prime on the first try?

Runs fine after it starts. One time yesterday it spuddered and then died shortly free it started. Check valave makes sense to me. Ill have to listen for the pump priming tomorrow.

I hear the pump prime. When I shut the Jeep off I hear gas filtering back into the tank, is that the one way valve or could it be a bad gas cap?

Try turning the key to run a couple of times without cranking. This would prime the system. Then crank and see if it starts right up or not. If it does, your problem is the anti flow back valve by the pump.

Alright ill give that a shot tomorrow. The Heep almost overheated today too, I think it may have been indication though. Sitting in a drivethrough line and check gauges light came on and nothing was weird then the temp gauge went from 220 to 250 in a split second. Then I started driving trying to air through it, drove a block and gauge went from 250 to 220 in a snap. I have no doubt it got hot I just don't know how hot. I plan on getting the coolant flushed and switching to a 190f thermostat and we'll see if it happens again.

if your temp sensor is wonky it would screw up your fuel mix

pull the codes and see if any other sensors are flaky, maybe a ground

Cycled the key twice and then waited to start on the third and it fired right up...guess that one is figured out. Thanks for the help. I'll get an update later on the overheat, I think I'm also going to put the electric fan on a manuel switch and run it more often.

Once the temperature gauge hits a certain point on it's scale, it'll peg to the right and the 'check gauges' light will come on. It doesn't necessarily mean the engine is at 250*F, however, it is a pretty good indication that something is wrong with your cooling system. Have you checked the fluid condition? Fluid level?

Sitting in traffic/drive-through and starts to overheat--I would suspect the mechanical fan's clutch.

I popped tithe Hood today and started the turd, the mechanical fan was spinning but the electric was not. Anybody know what temp the electric fan turns on at?

215-220 depending on year

sensors can be off by +/- 15 degrees easily

Mechanical fan clutches are fun!

After sitting all night the silicone fluid leaks out of the reservoir, so when the engine is started cold the fan clutch will engage until the fluid is "spun" back into the reservoir. When not engaged the fan clutch spins at 30 percent of shaft speed.

When the air passing through the radiator and hitting the bi-metal spring on the front of the fan clutch is at about 170 degrees (coolant in the engine will be at about 200 degrees), the bi-metal spring will slowly begin opening the valve and the silicone fluid will come out and start to engage the fan clutch. When fully engaged the standard fan clutch will turn at about 60~70 percent of shaft speed (an HD fan clutch will give you 80~90 percent of shaft speed).

How do you check a fan clutch? Well, there is a procedure in the FSM. A quick and dirty test is to first thing in the morning, before starting the engine, try and spin the fan clutch by hand a couple of times--mentally note the resistance felt. Then start the engine and let it run about 5 minutes, shut it off, and after the fan stops turning (easier on the fingers that way), try and spin the fan by hand again--the resistance felt should be less because all of the silicone fluid has been spun back into the reservoir and the bi-metal spring is keeping the valve closed. Ok, now restart the engine and drive it for 20 minutes to completely warm the engine, and make the last few minutes just driving around town. Shut the engine off, when the fan stops try again to spin it by hand--it should be STIFFER, if it isn't it should be replaced.

So I finally got around to changing the fuel pump today, which was easier than I thought. About 45min in and out once I got the Jeep in the air. Dropping the tank is a lot easier than I thought it was going to be so if you are apprehensive there is no need to be. But anyway the problem persists, it was only a pump replacement not a full replacement. Any other idea's on what it could be? I replaced the electrical fan motor and fixed the overheating issue. I tried to replace the mechanical clutch and Autozone failed to give me the correct clutch...as usual.

I have the exact same issue as POSJ. Any more word on this?

jragan said:

I have the exact same issue as POSJ. Any more word on this?

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BASICS--year/engine?

Same issue--the crank no start until you cycle the key or the overheating?

I am having the same issue with a 91 4.0 that I just picked up. I hear the fuel pump prime. Then when I cycle the key a few times hearing the pump each time it still will crank and crank before it starts sometimes. But it does not do it all the time.
Any ideas as to where to start at?