• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

91 XJ turns over but wont start

R

rockcrusher4210

NAXJA Forum User
Location
three links, KY
alright I moved from california to KY and the winter weather is playing hell on my jeep, one day I went to start my jeep and it just turned over very sluggish and didn't start. so I started trouble shooting, the batt. was first on my list but it's ok, it had 12.8 volts, the distributor cap and rotor are brand new and I check the coil for spark and the plugs, after all that then it wouldn't turnover at all!! so I put it in neutral and it turns over so I bypassed the NSS and it turns over in park now, I checked the cylinders to make sure they were getting fuel thats okay, so i have spark and fuel and no indicator lights. it still turns over very sluggish, but just wont fire, anybody I need help thanks
 
Clean your starter connectons including the ground connections to the motor. There is a direct wire ffome the battery to the starter and then the starter grounds through the motor back to the battery. If you have 12.8 volts and the connections are good and clean, but it won't crank good, your starter is probably worn out.

First issue is to get it to crank good. Are you sure the spark plugs aren't fouled out now?
 
I replaced the starter already and bench tested it, it seems okay, I'll try cleaning the neg. wire connection. and I only tested one sparkplug it hit every rotation, I just replaced the plugs with bosch platinum just 1000 miles ago. I haven't checked the crankshaft position sensor yet because I just replaced it a year ago (could that be the problem?)
 
if you've got spark and fuel, I'd doubt the crank sensor is the problem-- make sure the starter is still good and the the battery is strong enough for the vehicle.

How do you know the battery is good? Was it LOAD tested to verify it has enough power to crank the engine over? 12.8V is a valid surface charge, but if the internal plates have built up a sulfur coating, it still won't be able to provide the power it's capable of making.
 
Get it cranking strong first. Check/replace any rotten battery cables. Add another body-battery ground cable.

If you're very slow cranking, you're probably pulling the voltage down enough that you don't have spark. I think on the Renix (non-HO) setup if the voltage is below 9.6 volts then the ignition module won't fire.
 
Shorty said:
if you've got spark and fuel, I'd doubt the crank sensor is the problem-- make sure the starter is still good and the the battery is strong enough for the vehicle.

How do you know the battery is good? Was it LOAD tested to verify it has enough power to crank the engine over? 12.8V is a valid surface charge, but if the internal plates have built up a sulfur coating, it still won't be able to provide the power it's capable of making.
Click to expand...

And we have a WINNER!
 
I would say have the battery trickle charged overnight, if not for 24 hrs. Then load test it.
 
poor mans load test: crank it over with a volt meter connected to the battery. if it drops below 10v, its not enough to start it.
 
okay I tested the battery 5 different ways, spec garvity, volt, and load and I took it in to 2 different shops to have it checked and they said it was cool, but I didn't get the specific amps. i also took a battery out of a healthy running truck and i got the same thing. I did test the CPS and got a 0 ohm reading, it's under warranty still, oh and I did swap the old battery cables.
 
Yes, but is it still doing this?
"..turning over very sluggish ..."

Do you have ice in the engine block?
You need antifreeze in the east.
Is your waterpump turning during this cranking?

Tell us how you checked for spark.
What is your fuel pressure with key on after three seconds?
 
You must log in or register to reply here.

Similar threads

P
interment problem
Replies
3
Views
2K
cruiser54
C
S
98 XJ manual ignition problem
2
Replies
20
Views
4K
SurplusFan98
S
O
2000 XJ Failed Colorado Emissions high CO
2
Replies
27
Views
2K
Ken M
K
N
New Engine is Hard to Start
Replies
0
Views
32
NGThomas
N
Ecomike
87 Renix XJ No fuel, No brake lights, cranks fine
2
Replies
27
Views
848
Anak
Anak
Back
Top