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Hot Start Up Stumbling

cds36

cds36

NAXJA Forum User
Location
San Bernardino Ca
Hey all after days of reading posts figured id throw up my problem.

First off I have a 92 2wd. My problem started when I driving on a hot day on the freeway and the jeep just decided to die, so I pulled over and was like wtf tried starting it few time and it started right up. Well I did some research on the forums and decided to replace the “CPS Sensor”. Well I took it out again everything was normal went to put gas in turned off jeep, put gas in then went to turn on and it would turn but no start. It would want to start but it seemed like it was only run on one or 2 cylinders if that makes sense. Disconnected the batteries checked all wiring couldn’t find anything wrong. Well after it sat for a while bout an hour or so went to turn it on and it stumbled a bit, gave it some gas and it fired right up. Well I replace the CPS sensor again just incase. Next trip out everything seemed fine then it did it again, same symptoms driving on a hot day turned it off, went to turn on and would not start. I gave it some time and then it fired right up. I pretty sure now it’s got to be a temperature thing. When its on it runs great no problems or stumbling at all only at start up when hot. Also not getting any codes either

Since then I replaced

  • Cps Sensor twice to make sure
  • Spark Plugs
  • Spark Plug Wires
  • Fuel Pump
  • Fuel Filter
  • Ignition Coil
  • Distributor cap and rotor
  • Cam shaft position sensor or “stator sensor” in distributor
  • 02 sensor

Well went out for a drive and it did it again, thinking it could be the coolant temperature sensor “cts” or possible “Tps”. Any help would be appreciated.
 
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Funny you should mention that, I was working on my XJ this weekend, and I tried to start it hot with the coolant temperature sensor unplugged (forgot to plug it back in), and it would not start. Plugged it back in and it fired right up on the first crank. YMMV.
 
When you say "no start" do you mean it cranks but doesn't start?

Has your fuel pump been making any noise?
 
karstic said:
When you say "no start" do you mean it cranks but doesn't start?

Has your fuel pump been making any noise?
Click to expand...

Yes it cranks and at first it will start but sounds likes it running on a couple of cylinders not all 6, so i turn it off and try again, it cranks but then wont even start. If i give it some time to sit and try it it will either
  1. starts right up
  2. stumbles give it some gas then it fires right up
Now keep in mind this is only after I let it sit for a while. Well as far as the fuel pump I replace it just incase with a new one
 
Last edited:
karstic said:
I had the same exact problems, replaced fuel pump, problem solved.

Story of my saga

http://www.naxja.org/forum/showthread.php?t=925195&highlight=fuel+pump
Click to expand...


Haha that funny that was me who rescued you, the green jeep lol. But I put a whole new fuel pump and filter so im pretty sure its not that.

Damm this is killing me trying to find out what the hell it is. Guess I can look at it this way, I wont haft to worry about sensors after this saga has ended!!!
 
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check your fuel pump wiring harness and make sure you get good contact. with all the fab work done on your rig, did you relocate any of the fuel lines or electrical that might cause em to get hot?

if its a 92, could be vapor lock or your Choke vacuum
 
Nope Josh, had the issue before I EVEN touched it!!!!! Not my fault:anon:

P.S I checked everything out while I was under there too Craig!

djblade311 said:
check your fuel pump wiring harness and make sure you get good contact. with all the fab work done on your rig, did you relocate any of the fuel lines or electrical that might cause em to get hot?

if its a 92, could be vapor lock or your Choke vacuum
Click to expand...
 
hellbilly04 said:
Nope Josh, had the issue before I EVEN touched it!!!!! Not my fault:anon:

P.S I checked everything out while I was under there too Craig!
Click to expand...

X2 was doing it before went to billys, gonna try a new cts sensor and go from there.
 
How about an intermittent open in the PCM??? May sound a little far fetched, but you have replaced just about everything.. Since sensors tell the PCM what to do. Just a thought.. Sorry I don't have one for a 92 I only have Renix stuff... Maybe swap it out with Tony's and see if it effects his..
 
Clean-RC said:
How about an intermittent open in the PCM??? May sound a little far fetched, but you have replaced just about everything.. Since sensors tell the PCM what to do. Just a thought.. Sorry I don't have one for a 92 I only have Renix stuff... Maybe swap it out with Tony's and see if it effects his..
Click to expand...

Not a bad idea, i'll hit him up !! Just seemed wierd that it does that when hot and not cold
 
Last edited:
Ok guys im still haveing the problem. I cant figure out this sensor I think its a knock sensor but im not quite sure. Its on the driver side block right above the Oil Pan Lip. I think it might be a sensor for a aftermarket temp gauge that a shop put in a while back as the oem Temp gauge went out. Its Throwing back a 54 code "No fuel sync (camshaft signal) detected during engine cranking" but I replace the Stator Sensor with a new one. And it runs perfectly fine just having trouble when I try to start it when its hot.

IMG00073.jpg


Also If you can help me out with these sensors

IMG00070copy.jpg


And this is the temperature Coolant Sensor Correct

IMG00071copy.jpg
 
TPS sensor is on the front of the TB and one of those sensors with the three arrows is the MAT sensor and one is the vacuum connector for the CC I think. The last IDK. Mine is Renix as well as the prior poster so I can't go look at mine to tell you.
 
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