Author Topic: Best way to find tdc  (Read 3867 times)

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2.5Blues

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Best way to find tdc
« on: February 28, 2009, 05:29:40 PM »
I am having difficulty getting my jeep to run. I bought a jeep and it needed the distributor replace. I thought i had it on tdc. Now i cant get it to run. It cranks but doesnt start. I took the number one spark plug out and it sparks but not untill the second crank.. Any tips or advice would be great thanks

Offline Jeffy

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Re: Best way to find tdc
« Reply #1 on: February 28, 2009, 06:57:24 PM »
Take the spark plug out and put your finger over the hole sealing it.  Rotate the engine till your thumb 'pops' off.  That will be TDC on the compression stroke.
« Last Edit: March 01, 2009, 12:21:44 AM by Jeffy »
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2.5Blues

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Re: Best way to find tdc
« Reply #2 on: February 28, 2009, 07:55:39 PM »
Thanks i'll give that a try tomarrow.

2.5Blues

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Re: Best way to find tdc
« Reply #3 on: March 05, 2009, 12:57:57 PM »
I believe i set it right and still wont' start. Do i have to set anything in head? I also repalce tps would this cause it to not start?

2.5Blues

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Re: Best way to find tdc
« Reply #4 on: March 05, 2009, 02:09:45 PM »
I am not getting gas. I replaced pump, filter and injector right after i bought it. I have it set right cause it runs on starting fliud. No gas is coming out of injector. Not really sure can a tps sensor mess fuel up like this?

Offline Jeffy

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Re: Best way to find tdc
« Reply #5 on: March 05, 2009, 05:33:49 PM »
Can you hear the fuel pump prime when you turn the key to ON?
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"If the motor car were invented today, there is absolutely no way that any government in the world would let normal members of the public drive one."

2.5Blues

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Re: Best way to find tdc
« Reply #6 on: March 05, 2009, 07:04:51 PM »
yes i turn key and pump goes on. I am gonna put a nod light on it tomarrow.

2.5Blues

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Re: Best way to find tdc
« Reply #7 on: March 06, 2009, 02:25:48 PM »
I got injector pluse. wondering if some how a brand new injector could have failed already. You wouldn't think i havent even driven a hundred miles on new fuel system.

Offline aw12345

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Re: Best way to find tdc
« Reply #8 on: March 06, 2009, 08:54:30 PM »
If you have inkector pulse you have ignition, check fuel pressure to make sure the pump does it's job.
Also make sure that cyl1 is the one that fires at tdc and not #4
2006 Jeep Wrangler TJ SE
2004 Jeep Wrangler TJ SE

2.5Blues

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Re: Best way to find tdc
« Reply #9 on: March 06, 2009, 08:55:34 PM »
I got it running i have another problem. What would cause the timing to go past the graph located on the crank pulley? I thought the problem was the wrong distributor i replaced it. I checked with a timing light and it still goes outta the graph. The issue is that when i drive it stalls and sputters idles fine. The fuel system is new. plugs wires cap rotor new. I installed correct distributor.The tps and a bunch of vacum lines were replaced as well. I am kinda confused and not really sure why i am having such problems with sucha simple machine i think it hates me lol. any advise would be great.

Offline aw12345

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Re: Best way to find tdc
« Reply #10 on: March 06, 2009, 09:07:00 PM »
Use the correct procedure what ever that is for a 2.5l I don;t think you set it with a timing light if you do you have to find a way to disable the advance that is controlled by the ecm
2006 Jeep Wrangler TJ SE
2004 Jeep Wrangler TJ SE

Offline Jeffy

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Re: Best way to find tdc
« Reply #11 on: March 06, 2009, 09:17:59 PM »
I got it running i have another problem. What would cause the timing to go past the graph located on the crank pulley? I thought the problem was the wrong distributor i replaced it. I checked with a timing light and it still goes outta the graph. The issue is that when i drive it stalls and sputters idles fine. The fuel system is new. plugs wires cap rotor new. I installed correct distributor.The tps and a bunch of vacum lines were replaced as well. I am kinda confused and not really sure why i am having such problems with sucha simple machine i think it hates me lol. any advise would be great.
The distributer can't go in wrong.  Well it can but it would be 180* off.  The PCM controls timing and advances the timing automatically.  The Crank Position Sensor located on te bellhousing sends a signal to the PCM.  You can adjust timing a little with the CPS but it's normally non-adjsutable.
« Last Edit: March 06, 2009, 09:20:02 PM by Jeffy »
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"If the motor car were invented today, there is absolutely no way that any government in the world would let normal members of the public drive one."

Offline aw12345

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Re: Best way to find tdc
« Reply #12 on: March 06, 2009, 09:31:01 PM »
Goes back to check fuel pressure and checking the exhaust backpressure might not be a bad idea
2006 Jeep Wrangler TJ SE
2004 Jeep Wrangler TJ SE

2.5Blues

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Re: Best way to find tdc
« Reply #13 on: March 06, 2009, 09:36:47 PM »
I wasnt setting timing with the light only checking. I have a issues that i cant seem to figure out. I thought it was because it had a distributor from a 95. I have a 89 with a 95 bottom end and  trans i believe. I am just trying to get it to roll down the road without talling lol. Are there any compatablity issues between those? Everything else remains stock to a 89 i believe

Offline aw12345

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Re: Best way to find tdc
« Reply #14 on: March 06, 2009, 09:53:56 PM »
The timing being of will not make it stall a bad cranck sensor could
2006 Jeep Wrangler TJ SE
2004 Jeep Wrangler TJ SE