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No spark after engine swap

S

stockli

NAXJA Forum User
Location
Ft. Collins
Ok so we tried to get her started today and learn that there is no spark at all.
I checked the low voltage side of the coil and we are getting 12.6 volts there.

I have no idea where to begin looking for trouble since power is getting to the low voltage side of the coil. Im sure we missed something simple Im hoping you guys can shed some light on this.

Jeep is:
1989 Cherokee Limited
 
Did you plug the crank sensor back in? Seriously.

Did you hook up the head to firewall ground? It is the only OEM unibody ground.

Did you hook up the dipstick tube grounds? They are for the ICM, ECU, and o2 sensor as well as other important stuff.

Did you properly index the distributor? Getting it 180 out is common.
 
Fuel pump is kicking on, fuel is getting to the rail.

The CPS is plugged in as well as the ground strap on the back of the head.

I am almost positive we had two round connectors and the battery cable all grounded on the same bolt into the passenger side of the block. I will recheck all of that.

We indexed the distributor with the crank at 0 TDC on compression stroke then used the procedure to get the oil pump to 11 oclock and dropped the dizzy in to get the rotor just past terminal one. Just like it says in the shop manual.

Why would power be getting to the low tension side of the coil but not coming out of the coil? We tested this by pulling the dizzy wire and trying to jump arc to a head bolt. Nothing happened no arc at all.

Im cornfused.
 
Power to the ICM/coil comes from the B Latch relay, it also provides the 3-second prime power to the fuel pump.

The signal to collapse the field and fire the spark comes from the ECU, based on data from the CPS/CKP as it reads the flexplate/flywheel and generates a high or low signal.

So, without the CPS/CKP feeding data to the ECU, or the ECU failing to act upon the data, there will be no spark.

Measure the resistance of the crank sensor--it should be 200 ohms, + - 75 ohms, or a range of 125~275 ohms.

Did you use the 89 flexplate/flywheel AND crank sensor?
 
Yeah we used the original 89 flywheel and the CSP from the 89.

We also used the Dizzy from the 89. That is where the cam sensor is right or no?
 
Yes, the synch sensor is located in the distributor, however it will not prevent the engine from starting in the Renix XJs; it will in the 91+ (reportedly) as they are true Chrylser systems.

Either system, the synch sensor provides data to the ECU/PCM for the timing and duration of the injector pulse signal.
 
Two ring terminals plus the battery ground terminal.

I did notice one thing, close to the passenger side firewall where a wire harness splits there is a lone, what appears to be round female bullet style connector that isnt plugged into anything. Im not sure if that is intended to be not plugged in or if we are missing a plug for it.

Anyone know what that is and if it is supposed to be used or a "blank".
 
Bump, no one knows what that connector is?

Glad Im not the only one lol
 
I will post it up this week when I get back to the jeep.

Even if the dizzy was 180 out, we would still get juice flowing out of the coil at some point, right?
 
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