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RiCeMaN
May 18th, 2005, 23:19
Acquired a 91 XJ that was not running and didnt have a computer or trans in it. installed salvage yard computer, new coil, new fuel pump and new cap and rotor.
set TDC on crank, #1 piston and rotor put it all together and she will not start! No spark on #2 and # 5 cylinder. I used the same wire to check spark on all cylinders again 2 & 5 no spark any IDEAS?
thanks in advance for any info. I think it may be the computer?
also the trans is out and i just hooked up the flexplate bellhousing and starter just to try to get it to start. could the wrong flexplate if it is wrong cause this problem. ( my flexplate has three sets of four square holes around it for the CPS pickup)
thanks again
old_man
May 19th, 2005, 07:07
Double check the numbers on the computer. Could you have gotten the 4 cyl computer????
RiCeMaN
May 19th, 2005, 20:18
The computer i grabbed ddint have any numbers on it but it was on a 91 xj chassis. dont know if it was a 4 banger or not. Also just changed the computer and still no luck starting
RiCeMaN
May 20th, 2005, 20:26
Any ideas anyone ? help appreciated. changed CPS harness today still no ideas
what actually sends the signal to the coil for spark? is it tied in with injectors possibly
thanks
8Mud
May 20th, 2005, 20:49
Just a WAG (wild arsed guess) but might want to check the cam position sensor. Remeber reading about a no fire on 2 and 5 once long ago, but can´t bring it to mind again.
When you set TDC, are you sure you were on the compression stroke. I´ve gotten so I always throw a compression gauge in number one, when looking for TDC, I´ve been fooled a couple of times (with the thumb test) and tried to set it up on the wrong stroke.
Dirt
May 20th, 2005, 21:57
yeah what 8 mud sez
RiCeMaN
May 21st, 2005, 01:51
great idea on the compression tester i was kinda thinking that myself. in case i was tdc on exhaust stroke.
as for cam sensor i just bought a whole new distro (napa $55)and no luck same thing.
totally stumped on why no spark on those 2 cylinders. did research on the computer and its for a 91 auto .. so its the right computer..
RiCeMaN
May 23rd, 2005, 00:48
another update now i only have spark on cylinders 1 & 4
any help or ideas appreciated.
RiCeMaN
June 7th, 2005, 02:12
Well, come to find out it was the wrong flexplate.. the distance between the CPS and flexplate was just a tad to far for the sensor to operate properly..
Motor now runs excellent..thanks