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Renix crank no start

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Old May 7, 2013 | 01:07 AM
  #1  
123456bmx's Avatar
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From: Schaumburg IL
Year: 1990
Model: Cherokee
Engine: 4.0 I6
Default Renix crank no start

So today I drained and refilled my transmission with dex/merc III

I go to start it and It runs good for 30 seconds and shuts off on It's own,I've hooked it up to a charger and it makes no difference,just has no spark.

I took it for the highway trip of its life two days ago and it ran excellently.

Ran totally fine until I refilled the trans.My cps is hardwired so I don't think there's a connector issue.


1990 Xj
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Old May 7, 2013 | 07:50 AM
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From: Prescott, Az
Year: 1990
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Does it run for 30 seconds each time?

If so, the connections on the fuel pump ballast resistor can be corroded/loose.
Attached Thumbnails Renix crank no start-ballast-resistor.jpg  
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Old May 7, 2013 | 11:57 AM
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123456bmx's Avatar
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From: Schaumburg IL
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No it only ran for 30 seconds after the trans fluid change,and it's been no spark since

and I've got new connectors on the ballast resistor.

The cps is a couple months old.

Could it be the ignition control module?
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Old May 7, 2013 | 03:29 PM
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TEST the CPS.

Renix CPS Testing and Adjusting
 
 

Renix CPSs have to put out a strong enough signal to the ECU so that it will provide spark.

Most tests for the CPS suggest checking it for an ohms value. This is unreliable and can cause some wasted time and aggravation in your diagnosis of a no-start issue as the CPS will test good when in fact it is bad.

The problem with the ohms test is you can have the correct amount of resistance through the CPS but it isn’t generating enough voltage to trigger the ECU to provide spark.

Unplug the harness connector from the CPS. Using your voltmeter set on AC volts and probing both wires in the connector going to the CPS, crank the engine over. It won’t start with the CPS disconnected.

You should get a reading of .5 AC volts.

If you are down in the .35 AC volts range or lower on your meter reading, you can have intermittent crank/no-start conditions from your Renix Jeep. Some NEW CPSs (from the big box parts stores) have registered only .2 AC volts while reading the proper resistance!! That’s a definite no-start condition. Best to buy your CPS from Napa or the dealer.

Sometimes on a manual transmission equipped Renix Jeep there is an accumulation of debris on the tip of the CPS. It’s worn off clutch material and since the CPS is a magnet, the metal sticks to the tip of the CPS causing a reduced voltage signal. You MAY get by with cleaning the tip of the CPS off.

A little trick for increasing the output of your CPS is to drill out the upper mounting hole to 3/8" from the stock 5/16", or slot it so the CPS bracket rests on the bell housing when pushed down. Then, when mounting it, hold the CPS down as close to the flywheel as you can while tightening the bolts.



 

 

Revised 01-26-2013
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Old May 8, 2013 | 04:28 PM
  #5  
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Is your fuel pump priming ,and do you have fuel pressure?
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Old May 9, 2013 | 12:56 AM
  #6  
123456bmx's Avatar
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Originally Posted by cruiser54
TEST the CPS.

Renix CPS Testing and Adjusting
 
 

Renix CPSs have to put out a strong enough signal to the ECU so that it will provide spark.

Most tests for the CPS suggest checking it for an ohms value. This is unreliable and can cause some wasted time and aggravation in your diagnosis of a no-start issue as the CPS will test good when in fact it is bad.

The problem with the ohms test is you can have the correct amount of resistance through the CPS but it isn’t generating enough voltage to trigger the ECU to provide spark.

Unplug the harness connector from the CPS. Using your voltmeter set on AC volts and probing both wires in the connector going to the CPS, crank the engine over. It won’t start with the CPS disconnected.

You should get a reading of .5 AC volts.

If you are down in the .35 AC volts range or lower on your meter reading, you can have intermittent crank/no-start conditions from your Renix Jeep. Some NEW CPSs (from the big box parts stores) have registered only .2 AC volts while reading the proper resistance!! That’s a definite no-start condition. Best to buy your CPS from Napa or the dealer.

Sometimes on a manual transmission equipped Renix Jeep there is an accumulation of debris on the tip of the CPS. It’s worn off clutch material and since the CPS is a magnet, the metal sticks to the tip of the CPS causing a reduced voltage signal. You MAY get by with cleaning the tip of the CPS off.

A little trick for increasing the output of your CPS is to drill out the upper mounting hole to 3/8" from the stock 5/16", or slot it so the CPS bracket rests on the bell housing when pushed down. Then, when mounting it, hold the CPS down as close to the flywheel as you can while tightening the bolts.



 

 

Revised 01-26-2013
My cheapie multimeter doesn't read ac volts,but I'm just gonna buy an oem cps.

The one currently on the jeep is an ebay special.



Originally Posted by je4reyk
Is your fuel pump priming ,and do you have fuel pressure?
Fuel pressure is good,and fuel pump is loud and clear
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Old May 9, 2013 | 06:47 AM
  #7  
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Engine: 4.0
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$10 meter. Every Renix owner should have one.
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