Sorry if I post this wrong, I'm a newbie.

2001 Cherokee Classic, 165,000 miles. I have only had it a few months.

The first time I start it for the day it fires right up. Basically every time I start it again that same day the crank time is longer (3-5 seconds) and sometimes I have to try twice. This has been a fairly consistent pattern, although the crank time seems to have gotten longer and longer over the last month. It has never failed to start.

Could be a part going, or could be weather related. I bought it in the fall, now it's winter. I live in the rainy Pacific Northwest. I have put about 10,000 miles on it already.

Things I have tried:

-The "poor man's prime" (turning the key on/off to get fuel in the line if the pump is going bad). Has no effect.

-Replaced the spark plugs. I don't think I screwed this up, and it made no difference.

-I did a leak down test and everything seemed ok, but...

-I replaced o-rings on fuel injectors anyway. (I thought maybe fuel was leaking into a cylinder, creating a rich mixture, and evaporating overnight which is why it never happens first time in the day.) Unless I messed up, this isn't the problem. Although it was interesting to discover that someone had previously upgraded the injectors to a four-hole type.

-Cleaned IAC and throttle body.

-The battery is good and has relatively new terminals.

This might not matter, but I have experienced the cylinder 3 "heat soak" misfire issue and recently insulated the injector per service bulletin instructions. The misfire hasn't come back.

Assuming that this isn't weather or temperature related at all (which I think is true, but can't say for sure), what would cause it to fire right up when it's been sitting for ~10 hours, and otherwise requires a long crank time?

I'm getting good mileage. About 20 mpg highway.

Is there anyway it could be the CKS or CMS? I wanted to test resistance on the CKS plug, but I'm not sure which one it is (and it's raining and I don't have a garage). Pretty sure it's on the passenger side like the Grand Cherokee's and not on the driver's side like the older Cherokees (but that's not what the factory service manual says, which is frustrating.)

Has anyone else experienced this?

 

Were any injectors/plugs wet when you pulled them.?

 

The plugs definitely were not. I can't remember now about the injectors, it was a few weeks ago. I think they were wet on both ends because it had run earlier that day and there was a bunch of fuel in the rail that I had to flush out.

 

Have you checked for codes yet ?

 

Yes, thank you for the quick replies. Currently there are no codes.

There was an evap leak code that ended up being a rubber boot that needed to be replaced/reconnected and hasn't come back since. I've had the cylinder 3 misfire code twice related to heat soak. That's it.

 

Sounds like heat soak to me if it is happening after its hot and you try to restart it. Do some searches on that. There are some fixes.

 

Since its an 01... have you had the heat-soak recall fix applied

 

It's got the "debris shield" (part no. CBXCB060 ) if that's what you mean for the recall, although it's getting kinda ratty, I guess I could get a replacement. The #3 injector has the insulator sleeves now.

I'm leaning away from heat-soak being the problem. The long crank time has happened to me with temps in the teens after it's been sitting for an hour, so the engine should have been cold (right?). Also, the times where it has misfired it's been really obvious that the whole engine is shaking and the light comes on and flashes (and the re-start has been 5-15 minutes later, not an hour or two). This is really different than the usual 3-mississippi crank before it comes to life and runs smooth.

But, I'm by no means a mechanic. The injectors were from a ford, I'm not sure if I wrote down the part number anywhere (d'oh!). I did look it up online when I had them out, they weren't the ones most commonly put into xjs, but I found a couple people who had used them without any reported issues. Maybe they aren't a tight enough fit?

 

I have the same issue as the op on my 2000. I've owned it 2 years and I've learned to ignore it. But it is sometimes embarrassing when it takes 2 tries to start- even after the double prime

 

2000chersport, does it fire right up the first time you start it on any given day? Any idea if you have the stock injectors?

 

Leaky injector could cause the symptoms, sitting overnight is enough to evaporate. Good test is to pull the fuel rail with injectors and lay them over a strip of cardboard or newspaper, then prime the pump a couple of times and watch for drips

Could also be ignition related, a dying coil or something, but unlikely if it runs alright once it starts

 

Usually yes it fires up the first start of the day(usually long crank time though). It's seems like an identical problem to yours. I put in 784 injectors hoping it would fix it maybe but nope

 

Keep working at it. I have 784's on my 99', 182K miles, with a yellow top and its the fastest cranking vehicle I've seen.

 

I could see them being wet on the rail side because of fuel kept in because of pressure regulator. As far as engine side being wet could indicate leaking down issue. Have you ever ran any injector cleaner in the tank ?

 

Injector Operation

Injectors include a precision-ground needle valve and are controlled by an electro-magnetic solenoid that is turned on and off by an electric control unit. Fuel is injected only during the "on" time and is metered by the size of the opening, duration of "on" time, and fuel pressure.
Injector Service

Try cleaning them first. If this is not successful, they must be replaced.

Because of their construction, fuel injectors tend to "gum up" after 15,000 to 30,000 miles of driving. Fuel spraying from the injector must pass through a very small opening in the discharge nozzle. This is necessary to create a cone-shaped spray pattern that breaks the fuel up into a fine mist for proper atomization.

Some newer style injectors are more clog resistant than their predecessors, but all are vulnerable to some extent.

Every time the injector sprays fuel, a small amount remains in the nozzle. As it evaporates, it leaves behind a wax-like residue that forms hard varnish deposits.

The rate at which deposits build up depends on the quality of gasoline burned, whether or not the gas has detergent in it (and what kind), and the number of thermal cycles the engine experiences per miles driven. Short-trip driving builds up deposits more quickly than continuous driving.