So I have my 1994 Jeep Cherokee sport and it’ll drive for a good distance then it’ll shut down and show a check engine light but it’ll turn back on just fine . I’ve changed the CPS , I haven’t tried the computer and it’s timing is perfect I don’t see why it keeps doing this ... also the gas gauge doesn’t work ... I checked and the fuel pressure is fine ..

 

It looks like you live in California. Maybe the state has started sending out electromagnetic pulses to shut engines down so as to lower carbon emissions?

 

Did you check the relays and grounds and maybe the wiring at the ignition switch ,

 

I’m very new to these jeeps what relays would I check to know and how would I find the voltage that they need in order to function ...QUOTE=tech;3579164]Did you check the relays and grounds and maybe the wiring at the ignition switch ,[/QUOTE]

 

WHAT lol 😂

 

What relays would I check

 

the main one would be the auto shut down relay or ADS relay

 

What voltage should it be at ?

 

try swapping starter and fuel pump relays.

 

What code is it throwing?

And what brand of CPS did you put in?

 

The first thing a mechanic would do is read the code, to see if it indicates crank sensor issues, I presume you have read the code ?

 

In my experience, a failing CPS won't set a code, unless it has failed completely. It could be a loose connection in the circuit causing loss of the signal, making the PCM shut it down by dropping out the ASD relay. The ASD relay, or any relay, needs a full 12v for the coil to hold it in. This current is supplied by the PCM thru drivers, which are solid state relays themselves. They use 5v signals to switch 12v. The CPS signal is a pulsing 5v signal, so wiring connections are critical.

 

Start by cleaning your grounds.

See Cruiser54.com


And that CPS..... If it was not NGK/NTK, it's probably your problem.

But check your grounds.

 

This is good stuff here. I have known multiple with a 4.0 jeep for many years and nobody has ever mentioned a CPS throwing a code unless it is either not hooked up or damaged. Swapping motors or parts and however else the wires can get damaged I mean it happens. But many people have had the stalling issue and the CPS being the issue without a code

 

One thing I learned is if the CPS is bad The RPM gauge won’t move when cranking the engine. I had a bad CPS with an intermittent start problem