GrimmJeeper
NAXJA Forum User
- Location
- Gardena, CA
Time and time again I see threads come up on the same subjects, hopefully we can get together a post with enough keywords in it that this one compendium of troubleshooting will come up on a search result easily.
So, let's try to A.) keep on topic, and B.) try to use wording that will make this post easily searchable. try to remember that 3 character words will not be found by the vBulletin search engine.
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Probelm #1: No spark.
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Problem #2: turn the key, nothing happens.
Most likely cause: corrosion inside the Neutral Safety Switch, commonly referred to as the NSS. This sensor is located on the passenger side of the transmission, and tells the ECU that the transmission is in either "park" or "neutral" and it is OK to start the engine. Telltale sign that the NSS is starting to fail is the loss of reverse lights as corrosion builds up inside the switch itself. A quick fix is usually to start the engine with the transmission in neutral, but sometimes that will not work either. On 96 and earlier models the NSS can be bypassed by splicing together the two centermost wires in the connector that are on the row opposite the clip that holds the connector together (WARNING: This will make the engine able to start in any gear position, be aware that this will cause the vehicle to move suddenly when the key is turned if the gear selector is not in "P" or "N"). On 98 and later models the NSS cannot be bypassed as the engine computer uses input from the NSS to determine what gear to put the transmission in. Hopefully someone will link to the NSS cleaning/rebuilding procedure. Replacing it is also an option but it is somewhat expensive to do so.
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Please feel free to add to this thread, if it gets enough good info put into it maybe we can get it made into a sticky. Also if you've noticed any errors or misinformation report the post to a mod to have it corrected.
:cheers:
So, let's try to A.) keep on topic, and B.) try to use wording that will make this post easily searchable. try to remember that 3 character words will not be found by the vBulletin search engine.
_______________________________
Probelm #1: No spark.
The Jeep will crank over when I turn the key, but will not start. Has pressure at the fuel rail but will not fire.
Most likely cause: failure of the Crankshaft position sensor, commonly referred to as the CPS or CKPS. Inspect wiring to the sensor (which is located on the upper drivers side of the transmission bell housing) for melted or damaged wires, inspect connector(s) for corrosion or damage, test resistance and voltage with digital multi-meter. Replace if out of spec. Hopefully someone will post the CPS testing procedures for the renix and HO versions of the CPS._______________________________
Problem #2: turn the key, nothing happens.
Turn the key and the lights in the dash come on, the fuel pump primes, but when turned to the "start" position nothing happens.
Most likely cause: corrosion inside the Neutral Safety Switch, commonly referred to as the NSS. This sensor is located on the passenger side of the transmission, and tells the ECU that the transmission is in either "park" or "neutral" and it is OK to start the engine. Telltale sign that the NSS is starting to fail is the loss of reverse lights as corrosion builds up inside the switch itself. A quick fix is usually to start the engine with the transmission in neutral, but sometimes that will not work either. On 96 and earlier models the NSS can be bypassed by splicing together the two centermost wires in the connector that are on the row opposite the clip that holds the connector together (WARNING: This will make the engine able to start in any gear position, be aware that this will cause the vehicle to move suddenly when the key is turned if the gear selector is not in "P" or "N"). On 98 and later models the NSS cannot be bypassed as the engine computer uses input from the NSS to determine what gear to put the transmission in. Hopefully someone will link to the NSS cleaning/rebuilding procedure. Replacing it is also an option but it is somewhat expensive to do so.
_______________________________
Please feel free to add to this thread, if it gets enough good info put into it maybe we can get it made into a sticky. Also if you've noticed any errors or misinformation report the post to a mod to have it corrected.
:cheers: