No Codes Sputters on hot start.

Ok y'all here is my deal 1999 4x4 5 speed 4.0l 160,000 miles...
When I start my jeep up sometimes when it ran maybe within 2 hours of it being previously run it will crank just fine run for a minute or two and then just start sputtering out real hard unless i give it some major throttle and then it usually goes away. Now I got the jeep ruffly a month ago and I think it sat for at least 3-4 months with out being run.

I have run countless fuel injection cleaners through it, and conditioners. I have sea foamed the intake manifold checked all the plugs which seem fine the cap and rotor and wires all seem new.

It has had a check engine light come and go. I screened the computer this morning and got no codes comming from it. Any input would be great.

Would the CPS do this?

ohh yea also, im taking it on a 2500 mile road trip from florida to wyoming so im trying to figure out if this is gonna kill me on the way.

i would say its a weak/bad battery. have the battery tested.

Sounds similar to my situation but mine had a code for the Coolant Temperature Sensor. Coolant temp was at 210 degrees but the sensor was reading 110 degrees. this was causing it to run super rich and sputter and eventually not stay running. Mine had fouled out to the point that it was letting coolant to seep back into the wiring harness and that needs replacement too. whole job was approximately $240 including the sensor,wiring harness and Labor.

ktwalker01 said:

ohh yea also, im taking it on a 2500 mile road trip from florida to wyoming so im trying to figure out if this is gonna kill me on the way.

Click to expand...

So you hooked up a ODB(sp?) code reader to the port and there were no codes?

I thought the codes were stored for 75 miles or something like that.

You need the codes. The codes will tell you, or give you a clue to the problem, or you can just randomly start replacing sensors.

yeah I hooked it up to computer this morning as advance auto and saw nothing... I'm out of ideas and I dont have money to start throwing in new sensors grrr... I mean the problem only happens on a hot start it will start sputter and not reving gradually for a normally acceraltion and the engine will buck so i just hold down the clutch n give a good couple hard revs and the problem goes away. It has never fully "stalled out".

The battery is good along with the terminals, and also the the temp gauge reads correct.

If you search around, you come across some posts about this heat soak problem. If yours is doing the same thing, then the residual heat is creating a vapor lock in the fuel injectors. Once you clear out the vapor, it runs fine. The fix is to put some heat shields around the #3&4 injectors. I think it's a TSB.

ktwalker01 said:

yeah I hooked it up to computer this morning as advance auto and saw nothing... I'm out of ideas and I dont have money to start throwing in new sensors grrr... I mean the problem only happens on a hot start it will start sputter and not reving gradually for a normally acceraltion and the engine will buck so i just hold down the clutch n give a good couple hard revs and the problem goes away. It has never fully "stalled out".

The battery is good along with the terminals, and also the the temp gauge reads correct.

Click to expand...

Hmmm, well I wonder if the lack of code(s) is the clue. Bad computer? I'll let someone else step in here to help you further. The code is where I would have to start.

I had a faulty upstream O2 sensor do something similar. After I parked it, it would start up, spit stumble rev up etc. If I put it to the floor, it would go away, then idle normal. Noise feedback from the O2 sensor heater circuit was messing things up. Never threw a CEL.

1803103 - 4.0L ROUGH ENGINE IDLE AFTER RESTART FOLLOWING A HOT SOAK
Date: 09/05/03 (supercedes 1802702 dated 09/06/02)

Model Year(s): 1999-2004

Description: NOTE: This bulletin applies to vehicles equipped with a 4.0L engine. This bulletin involves the installation of a fuel injector insulator sleeve.

Details: Customers may describe a 20 to 30 second rough idle following the restart of a heat soaked engine. This condition may be most noticeable when the engine is restarted following a prior 10 to 20 minute heat soak in hot ambient conditions of approximately 32 C (90ºF) or higher. This condition may be consistent with short city stop-and-go driving trips and can be aggravated by the use of fuel with a high ethanol content. Depending upon various conditions a MIL may occur due to DTC P0303 - Cylinder #3 Misfire.

This condition may be caused by heat from the exhaust manifold that following engine shut down migrates to the area around injector #3 and causes fuel vapor to form within the injector. This in turn may cause a momentary misfire of cylinder #3 until the fuel vapor is cleared of injector #3. The insulator sleeve lowers the injector #3 temperature to a point below which the fuel will not normally vaporize.

If vehicle exhibits a rough idle, and if a misfire of cylinder #3 is observed following a 10 to 20 minute hot soak, perform the Repair Procedure.

Parts required:
56028371AA Ignition Wire Shield

Repair procedure:
1. Cut insulator sleeve, p/n 56028371AA, to make two (2) insulator sleeves about 25-30 mm (1 in.) in length. See diagram.
2. Install one sleeve around injector #3, with the slit on the upward facing side of the injector. Install the other sleeve with the slit on the downward facing side of the injector.
3. Confirm sleeve is flush to intake manifold surface around injector.
4. Check injector #3 wire and ensure that the injector is rotated to a 2 o'clock position (from driver’s side of vehicle).

your a hero man, I had no idea what heat soaking was so i didnt know where to look, I will do this and see where it goes from there. Thanks for the input guys

You think I can use heat wrap for like an exhaust around the injectors?

Here's the actual TSB

http://www.wjjeeps.com/tsb/tsb_wj_1803103.pdf

98XJSport said:

I had a faulty upstream O2 sensor do something similar. After I parked it, it would start up, spit stumble rev up etc. If I put it to the floor, it would go away, then idle normal. Noise feedback from the O2 sensor heater circuit was messing things up. Never threw a CEL.

Click to expand...

X2.

sweet well im gonna make some of these for them and see how well it works, and if it persists I will do the upstream O2

Mudderoy said:

So you hooked up a ODB(sp?) code reader to the port and there were no codes?

I thought the codes were stored for 75 miles or something like that.

You need the codes. The codes will tell you, or give you a clue to the problem, or you can just randomly start replacing sensors.

Click to expand...

Or use a multimeter to test sensors.