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2.5 motor turns wont start no fire from coil

3K views 12 replies 7 participants last post by  vwjeep 
#1 ·
Swaped out motors 2.5 for a new one with less miles. My cousin disconnected all of the wiring near exhaust manifold. Now motor in will turn but wont start. Coil has no fire. Loookinng to find out wher coil gets source of power and maybe follow short or fuse any insight on this would be great! Thank you
vwjeep
 
#3 ·
I see the jeep in your profile is a '89, in you questiom you state you swapped out the original for a new one with less miles. What year did you install? Are the electronics the same? I have a 89 also, if you went beyond a 91 ( I think its 91) The computers are more ellabrit, and on some of the newer ones you would need to take the whole wiring harnesss and computer from the doner and splice in the harnesses.
The easy way would be to just change out the engine, all fuel and ignition systems would be used off the original engine.
Did you disconect the starter relay durring the swap? Make sure all the wires are back on it. Both starter wires are on the starter right?
Using a test light check primary side of coil for voltage with the key on. Check ignition fuses for continuity, test light has voltage on both sides of the fuse with key on.
Is the fuel pump working? Does it prime when you turn the key? turn the key on and listen for it to run, I know this isnt a fuel problem but it would indicate a path of failure in the ignition circuitry if it isnt working.
Are all of the grounds hooked up? should be a bundle on the dip stick tube stud and a ground strap from the head to the fire wall.
After this is ECM and what primitive computer stuff that is on the motor. But I have a feeling it is something that was missed durring the install.
 
#4 ·
thanks for the help. is there a diagram that you can post for me to get an idea what to look for. Meanwhile I will look for it and trace the plug. Question
when I installed the newer motor I use the clutch that came with the Motor.
The newer Motor's Flywheel just had teeth for the starter. While my older motor has 2 plates one for the starter motor. and another for this sensor I guess your telling me about since my distributor has no wires leading to it. can you please confirm if this is right. If so I will have to put thesensor plate
off of my older motor on
to the flywheel on the newer motor to get spark. if this is right it explains why I am not getting any spark from the Distributor. I am gettin power to the coil checked it with a test light
 
#6 ·
98 joe Thank you yep its a 89 and i believe the new one is a 94. I swaped everything off the motor except the 2nd plate with teeth attached to the fly wheel. I really would like to change the electroonics so I dont have to put this 2nd plate to the flywheel. any suggestions are welcomed Thanks again vwjeep
 
#7 · (Edited)
OUCH! That sucks man. but hey, now that you know the problem its just time and effort, and you will have it back together and running. It'll be worth it when its done. Good luck.
As to swapping everything else to avoid pulling the engine part duex. I hink its 6 of one half adozen of another. It may be physicaly easyer to do the electrical swapp if you have everything you need from the donor and the scematics (sp)to do it. but if something goes wrong you are back to square one again.
I was actually going to write it might be a good way tofix it, but, I erased it and here is why. the new motor has multi port F.I. if I am not mistaken, so you would also nee the fuel tank the fuel pump and all the lines. because it uses a higher presure pump than the old T.B.I system. Also you are in Ca. , I am not certain how that would effect your emision control inspection. wrong year emision controls, no check engine light to support it. etc.
I think it would be easyer to change the flywheel. Or, just a thought maybe drop the trans and change the flywheel from underneath? just thinking out loud.
 
#8 ·
I'm not familiar enough with the differences between the two years, except that I believe the computers used were different. If you look the cps sensors from the two years up, they look a bit different physically as well, but that may or may not matter. Hopefully someone with some experience with this will chime in, I'm sure someone knows for sure. Just hang in there till someone with the knowlege reads the thread, or try searching the forum, it may be covered somewhere already.
 
#10 ·
Easiest thing to do is to swap the '89 flywheel back onto the new motor. If your intent is to keep the '94 flywheel, then you will need to completely convert your '89 over to the '94 electronics (including ecm), along with the MPFI setup as opposed to TBI(the previous supplied thread goes into the detail). Here are comparison pics of the two model year flywheels(2.5L), '89 on the left and '91-'95 on the right. The timing notches for the CPS are totally different and are used for the cps to feed the ecm to control spark and injector(s) pulse.
 

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