TJ turns over but won’t start

tworley

TJ Addict
Supporting Member
Ride of the Month Winner
May 23, 2018
1,895
Morrison, CO
I found this link helpful a few years ago when I couldnt get my jeep started.


Im still betting money on the ignition pickup coil:). In all seriousness though, I hope you do get it started soon, you've put a ton of work into that thing this last year.
 
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Igoo65

Igoo65

TJ Enthusiast
Jan 7, 2019
174
Colorado Springs, CO
Ok here is what I have so far. I tested the coil and it is within spec, so good. I checked voltage (digital voltage meter) going to the coil while my lovely assistant (wife) turned the key on. The green/black wire 0v, white wire 11v. Checked the same with light probe. Green/black no light, white wire has light. Shouldn't these results be on the opposite wires? My light probe has two lights green for ground and red for voltage. When probe on the white wire and key off, I have a green light. With the key on I have a red light. The ASD relay is clicking and I can hear the fuel pump kick on. So what now?
 

TJ Hunnicutt

TJ Enthusiast
Supporting Member
Apr 5, 2018
631
Texas, USA
I'd have to do some checking after work on the wire colors, etc. but the 11 volts sounds pretty low. What are you getting at the battery with the key on?
 

TJ Hunnicutt

TJ Enthusiast
Supporting Member
Apr 5, 2018
631
Texas, USA
OK, your batt's probably fine, just run down from cranking. But, assuming good contact with your meter, you should have the same voltage at the coil (within a couple tenths) as you have at the battery. If you are losing a volt or more, there may well be a wiring/connection issue.
 
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Igoo65

Igoo65

TJ Enthusiast
Jan 7, 2019
174
Colorado Springs, CO
Ok I will check my connections when I get home and retest after the battery is fully charged. I am just curious about the wire switch? I will check that again also.
 

mainegirl

New Member
Feb 12, 2019
21
fairfield, maine
Hi, did you do a compression test? Sometimes when you put a new engine in the cylinders can become gas washed from the initial starting trial. Take a squirt bottle and spray a little oil in each cylinder to bring up the compression.
 
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Jamison C

TJ Padawan
Supporting Member
Sep 1, 2018
321
Sedona, AZ
Something I would like to throw out. Jerry has mentioned in the past that early 97 models (technically 96 production) use similar parts found on the 95 wranglers, and I believe the CAM sensor is one of those. Is it possible that you have an EARLY 97 engine and are using the LATER 97 distributor/cam, or vice versa?
 
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Igoo65

Igoo65

TJ Enthusiast
Jan 7, 2019
174
Colorado Springs, CO
Hi, did you do a compression test? Sometimes when you put a new engine in the cylinders can become gas washed from the initial starting trial. Take a squirt bottle and spray a little oil in each cylinder to bring up the compression.
I did do a compression test and I was at 120-125 for all cylinders. FSM say 120-150. I was surprised that my compression was on the bottom of the scale. I will ad some oil.
Thanks
 
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Igoo65

Igoo65

TJ Enthusiast
Jan 7, 2019
174
Colorado Springs, CO
Something I would like to throw out. Jerry has mentioned in the past that early 97 models (technically 96 production) use similar parts found on the 95 wranglers, and I believe the CAM sensor is one of those. Is it possible that you have an EARLY 97 engine and are using the LATER 97 distributor/cam, or vice versa?
Would that account for the flip/flop of having voltage on the opposite wire?
 

Jamison C

TJ Padawan
Supporting Member
Sep 1, 2018
321
Sedona, AZ
Would that account for the flip/flop of having voltage on the opposite wire?
I think that’s highly possible. I would research a little on the voltage readings on the CAM for the 95 4.0 wranglers, and see if maybe you have the wrong sensor installed. If you’re having a “flip flop” on wiring I’d suspect that’s the culprit. You have everything required to start the Jeep, spark, fuel, compression, it just sounds like your timing is out of whack.
 

Jamison C

TJ Padawan
Supporting Member
Sep 1, 2018
321
Sedona, AZ
I did check the timing again and I am on the #1 pole on the distributor with the engine on TDC of the compression stroke.
Right I get that, I mean if the sensor is wrong it’s likely to mess up your set timing with an improper spark plug firing order.
 
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Igoo65

Igoo65

TJ Enthusiast
Jan 7, 2019
174
Colorado Springs, CO
Oh OK. Thanks. The thing I don't get is that my jeep ran flawlessly before I installed the new engine. I don't know what would have changed.
 

tworley

TJ Addict
Supporting Member
Ride of the Month Winner
May 23, 2018
1,895
Morrison, CO
Something I would like to throw out. Jerry has mentioned in the past that early 97 models (technically 96 production) use similar parts found on the 95 wranglers, and I believe the CAM sensor is one of those. Is it possible that you have an EARLY 97 engine and are using the LATER 97 distributor/cam, or vice versa?
Good thought. Craig, do you have your old engine still?
 
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Igoo65

Igoo65

TJ Enthusiast
Jan 7, 2019
174
Colorado Springs, CO
I don't. I gave the engine builder mine when he dropped the new engine off. I do have my old distributor. I'm not sure how this would matter.