Jeep Strokers

i just rebuilt the motor to a 4.6 stroker renix but now it wont run right it backfires and stumbles and pops out the rear like the timing is off but it is not. with the timing marks lined up and the distributer at the 1st spark plug its 180 degrees off so i fliped it 180 degrees and it fires up but does all the backfiring nonsence so i have redone the timing 4 times just to make sure i also have done a compresion test all the valves are opening and closing correctly the cps has been changed new wires new plugs new cap new roter and cylinders 1, 3, and 6 have no spark

so here are things ive done a buddy of mine has a renix xj as well so we decided to swap a few parts to see if we could fix mine computer and ditributor map sensor have also turned the distributor one tooth at a time to see if could find the right timing but same issue

what i have and have not done on this build
pistons h802pc
cam stock
new lifters
reconditioned crank from 89 4.2 light crank
352 conecting rods
new melling oil pump
24lb injectors
cloyes double roller if it makes a difference

parts i reused all i did was clean them
head
intake manifold
exhaust manifold
throttle boddy

Are you 100% sure 1, 3 and 6 aren't getting spark? If so there has to be something wrong with the distributor or wires.

Did you use Dino's write up to index the distributor?

SilverXJ wrote:Are you 100% sure 1, 3 and 6 aren't getting spark? If so there has to be something wrong with the distributor or wires.

Did you use Dino's write up to index the distributor?

I put my distributor in my buddies xj and it actually fixed his sputtering problem so i know mine is fine with that being saidno i didnt look at dinos write but i will now

justjerald wrote:

SilverXJ wrote:Are you 100% sure 1, 3 and 6 aren't getting spark? If so there has to be something wrong with the distributor or wires.

Did you use Dino's write up to index the distributor?

I put my distributor in my buddies xj and it actually fixed his sputtering problem so i know mine is fine with that being saidno i didnt look at dinos write but i will now

dinos did nothing for me

Have you tried exchanging plugs / wires with known good ones? If you swap plugs and wires does the no-spark condition change? You said the distributor was tested and should be fine, that only leaves the wires, plugs, and the spark plug ground where it screws into the block. You can use a spark plug tap to chase the threads and make sure they are clean. How do you know those cylinders do not have spark, did you use a spark plug tester? When you ran your compression test, what were the results? If a cylinder is too low it will act like it has no spark.

My buddy changed his plugs the other day and had the same thing happen, sputtered. He thought he had the timing off or had crossed wires or had messed up an end. Turns out he had a bad plug (brand new). Swapped it out and ran like a top.

Make sure your distributor is properly indexed and if it's an automatic make sure you didn't damage the flex plate when installing the engine.

unlimitedrubicon wrote:Have you tried exchanging plugs / wires with known good ones? If you swap plugs and wires does the no-spark condition change? You said the distributor was tested and should be fine, that only leaves the wires, plugs, and the spark plug ground where it screws into the block. You can use a spark plug tap to chase the threads and make sure they are clean. How do you know those cylinders do not have spark, did you use a spark plug tester? When you ran your compression test, what were the results? If a cylinder is too low it will act like it has no spark.

you know I was thinking that about it not grounding right. But I pull the plug and hold it to a ground still no spark even with a well known spark plug

johnhalabama wrote:My buddy changed his plugs the other day and had the same thing happen, sputtered. He thought he had the timing off or had crossed wires or had messed up an end. Turns out he had a bad plug (brand new). Swapped it out and ran like a top.

This is a possability so ill look into that

91JeepMJ wrote:Make sure your distributor is properly indexed and if it's an automatic make sure you didn't damage the flex plate when installing the engine.

I thought as well at one point I even droped the tranny took it off and had it checked out it was fine

hows your cap and rotor look? maybe youre overlooking something simple?

what if you take a plug from 2,4,5 that you know has spark and put it in the wire of 1,3,6 to see if you have spark then. if not than take a wire from 2,4,or 5 and put it in the 1,3, or, 6 spot to see if that does anything. cause it could be in your wires

amcinstaller wrote:hows your cap and rotor look? maybe youre overlooking something simple?

Brand new still have the old ones too

92tank wrote:what if you take a plug from 2,4,5 that you know has spark and put it in the wire of 1,3,6 to see if you have spark then. if not than take a wire from 2,4,or 5 and put it in the 1,3, or, 6 spot to see if that does anything. cause it could be in your wires

Word! I'm gonna try this n get back to you in about 30 minutes

Ok so I tried to change the cap and rotor again also checked the spark at the cap points 2, 3, 4, & 5 are sparking 3 is intermittent. 1 & 6 have no spark coming from cap also have an extra coil and ignition control module that I swapped out and same problem I've also replaced the wiring harness from the computer to the engine