Need Help Diagnosing Issue after Engine Swap -
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post #1 of 4 Old 07-20-2021, 06:50 PM Thread Starter
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2000 WJ 
Join Date: Feb 2015
Location: Berlin
Posts: 4
Need Help Diagnosing Issue after Engine Swap

Hi All

I have a 2000 WJ that threw a piston through the block back in March. I bought an ATK stroker to swap in, have it installed, troubleshooted a few issues, and cant seem to find my way around this one. With the new engine I replaced the crank sensor, cam postion sensor, oil pump drive, oil pump and pickup, oil pan, spark plugs, coil pack, fuel injectors (Four Hole), throttle body, crank pulley (dampener), oil pressure sensor. The water pump, temp sensor, and other accessories were all replaced about 10k miles prior to the incident.
With all that said, the engine cranks, and almost turns over on its own. If I crank it with the accelerator pressed it will run, roughly and die when I let my foot off the accelerator. It sounds like it it firing out of the intake when it runs sometimes but other times it sounds great over 2k rpm. The other problem is that the voltage gauge doesn't ever move. I'm not sure if the two problems could be related. It hasn't thrown a code this whole time, including when there was a hole in the block and no oil pressure, but the CEL did flash when it was misfiring. While it runs, I get a check gauges light.
I've tried the new and old cam postion sensor and oil pump drive, I've swapped back to the old coil pack, the old fuel injectors, checked the timing marks on the chain, checked fuel pressure, checked voltage at the 5V sensors that cause common issues. After reading on here a bit all I can think to do now is to go through all the grounds again, and then from there the only other thing I can think of is the PCM.

Any help would be greatly appreciated, and if you have any questions I'll do my best to answer them.

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post #2 of 4 Old 07-23-2021, 06:24 AM
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2000 TJ Wrangler 
Join Date: Jul 2019
Location: Tampa
Posts: 191
Need Help Diagnosing Issue after Engine Swap

Id start with a compression test. Is your timing or cam position sensor 180 out maybe?
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post #3 of 4 Old 07-26-2021, 01:53 PM
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2010 JK Wrangler 
Join Date: Dec 2002
Location: Massachusetts
Posts: 7,349
Maybe a throttle position sensor issue. It is located the the throttle body. remove it and clean it with carb cleaner. Clean the bore it sits in also. DO NOT pull the pintle out of the throttle position sensor! If you do, throw it out and buy another one. Make sure you dump the learned memory from the brain. To do so you take the + battery cable off the battery, and ground out end for 30 seconds or so. Slap it back on and see what it does then. If it starts and runs take it for a ride until the thermostat opens and the vehicle goes into closed loop mode, so it can begin 'learning' again.

Do you know what was good about the good old days? I wasn't good, And I wasn't old!

Found out Grandpa is addicted to Viagra. No one is taking it harder than Grandma...
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post #4 of 4 Old 07-26-2021, 10:34 PM
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1984 CJ7 
Join Date: Sep 2018
Location: Joplin
Posts: 653
Has it been like this since the swap? If so make sure the plugs all look good and that the wires are all on the correct plug.

Check all the grounds but look over the entire harness for cuts or something not plugged in.

Try to find your volt meter issue. If the system senses there is not enough volts it will shut down and can stay stuck in that mode.

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atk , engine , stroker , timing , wj

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