warf90 Posted February 24, 2007 Share Posted February 24, 2007 I just helped my friend put a Motor in his Wrangler. It a 4.0. We got it all back together and it will not start. I have verified fuel pressure and spark. We had to switch distributors. I got it up on top dead center and set the distributor and I doubled checked to make sure we had everything hooked back up. Its not even trying to hit or sound like it is trying to start. Its a 91. Any one have any ideas or maybe you guys can think of something that I have not. Thanks Link to comment Share on other sites More sharing options...
Rokhound Posted February 25, 2007 Share Posted February 25, 2007 would that have CPS if it does check that Link to comment Share on other sites More sharing options...
warf90 Posted February 25, 2007 Author Share Posted February 25, 2007 Do you mean the crank angle sensor? Yes it does have one. I have thought of that, the only thing, we reused his old one and it ran fine before we did the engine change. Link to comment Share on other sites More sharing options...
Eagle Posted February 25, 2007 Share Posted February 25, 2007 You need to be certain the CPS is the correct one for the year of the vehicle, and that the distributor also matches by year. The entire ignition/injection setup changed in the 1991 model year, and parts from the 87 - 90 4.0L will not work with the 91+. However, if you have spark I assume that's okay, and you said you have spark. When you set up the distributor at TDC, are you certain that #1 piston was at TDC on the compression stroke? If it was on the exhaust stroke, your distributor will be 180 degrees out of phase. Don't forget, on a 4-cycle engine the engine rotates through two revolutions for one revolution of the distributor. Link to comment Share on other sites More sharing options...
warf90 Posted February 26, 2007 Author Share Posted February 26, 2007 I reused his distributor, crank angle sensor, intake with all injector and such. I basically installed a long block. I am starting to doubt myself as far as getting the distributor set right. I am going to check that tonight when I get home. I am going to start over and get it up on tdc and double check and make sure I got it right. Link to comment Share on other sites More sharing options...
carnuck Posted February 26, 2007 Share Posted February 26, 2007 is the motor from an older XJ? Did you change the flywheel to the original? If not, it won't start. Link to comment Share on other sites More sharing options...
warf90 Posted February 26, 2007 Author Share Posted February 26, 2007 Yes I changed the fly wheel also. The motor we installed was from an Automatic XJ. His wrangler is a manual trans. I am going to recheck that I have the distribor right and I will let you guys know what happens. Thanks for all the input and ideas. Link to comment Share on other sites More sharing options...
warf90 Posted February 27, 2007 Author Share Posted February 27, 2007 Well I finally got it to start, I had the distributor set wrong. I had it running for a while and made sure everything was good and the thermostat opened. Turned it off and everytime you go to start it, it takes for ever to start. Its almost like it is flooding out. My friend said that even before the motor change that sometimes it would just crank and crank. He said that he would have to hold the pedal to that floor to get it to start. CPS going bad maybe? Any thoughts? Link to comment Share on other sites More sharing options...
Pete M Posted February 27, 2007 Share Posted February 27, 2007 Yup, long cranking times can be an indication of a failing/dirty CPS or a weak signal due to corrosion in the connector. The computer won't fire the engine until it is absolutely positively certain where the engine is in its rotation. Link to comment Share on other sites More sharing options...
carnuck Posted March 2, 2007 Share Posted March 2, 2007 You could still be out on the dist positioning. Link to comment Share on other sites More sharing options...
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