onlyinajeep726 Posted May 14, 2016 Share Posted May 14, 2016 Like the title says, my MJ won't start... I JUST got plates back on it this morning and on the way home, radiator busted and overheated right as I was getting on my road. It shut off before I got to my driveway and I coasted to the parking pad. I let it cool, swapped in a new radiator, washed the engine and entire bay (since it had antifreeze all over it), started it up and let it run till operating temp. Idle RPMs kept going up, and I figured out the manifold bolts were loose, so I tightened them. TRIED to start it again after that, and nothing. Just turns over and over, but no fire.Checked CPS, TPS, MAP, coil, plugs, the harnesses, etc. The only thing I noticed is that the injector plugs weren't showing any voltage on my multimeter when I tried cranking it. Seems logical that it would pulse the injectors to give fuel when starting, but nothing showed on the MM in either DC or AC voltage mode... Could that be my issue? Did I somehow fry my ECU? Link to comment Share on other sites More sharing options...
MJCARENA Posted May 14, 2016 Share Posted May 14, 2016 Check the voltage on the CPS while cranking. You could also try unplugging and reconnecting the CPS connector a couple of times to clean the terminals. My XJ would not start sometimes because of a dirty CPS connector. Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted May 14, 2016 Author Share Posted May 14, 2016 Check the voltage on the CPS while cranking. You could also try unplugging and reconnecting the CPS connector a couple of times to clean the terminals. My XJ would not start sometimes because of a dirty CPS connector. CPS is brand new and doing Cruisers method for testing it shows a 0.8 AC voltage reading while cranking, which is well above what is needed to tell the ECM to fire. Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted May 16, 2016 Author Share Posted May 16, 2016 Figured it out... TPS died. Strange since it tested alright, but unplugging it allowed it to start... Can't quite wrap my mind around that. :dunno: Link to comment Share on other sites More sharing options...
cruiser54 Posted May 16, 2016 Share Posted May 16, 2016 Figured it out... TPS died. Strange since it tested alright, but unplugging it allowed it to start... Can't quite wrap my mind around that. :dunno: Nope. Test the connectors in the TPS harness, vehicle side. A should be about 5 volts DC with key On. B should be less than an ohm resistance. Link to comment Share on other sites More sharing options...
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