snakedoc67 Posted October 30, 2013 Share Posted October 30, 2013 my manche has been taking more effort to start than normal. When its cold it takes over 30 seconds of cranking with frantic pumping of the gas pedal as i crank the starter before it fires. Its been doing it for awhile, probably 4-5 months now. Refreshed the grounds at the oil dipstick earlier this summer, replaced the battery and positive cable a few days ago. Before replacing the battery it was every time I started it, afterwards it started fine when the engine was warm. Any ideas would be great. Link to comment Share on other sites More sharing options...
cruiser54 Posted October 30, 2013 Share Posted October 30, 2013 Undo the braided cable at the firewall. Remove all paint form the firewall. Reinstall the cable. Better yet, run an extra one from the firewall to the intake manifold. Stick shift? Maybe there's a buildup of clutch material stuck to the tip of the CPS. Read this: 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 Link to comment Share on other sites More sharing options...
carnuck Posted November 1, 2013 Share Posted November 1, 2013 I added a braided strap from the block to the frame at the motor mount (like FSJs have) Link to comment Share on other sites More sharing options...
snakedoc67 Posted November 2, 2013 Author Share Posted November 2, 2013 i already have a cable ready to be installed per Crusiers Renix tips, just havent gotten around to it due to work and weather. Link to comment Share on other sites More sharing options...
Eagle Posted November 2, 2013 Share Posted November 2, 2013 Pumping the gas peddle is NOT an appropriate way to start a vehicle with electronic fuel injection. That worked in the days of carburetors because it cycled the accelerator pump to get gas into the cylinders. That's not necessary when you have an electronic squirter pushing the fuel in there at 39 psi. All you're going is opening the throttle body plate and making the mix LESS rich, when you really need it as rich as possible to start. Keep your foot off the gas peddle when starting. Link to comment Share on other sites More sharing options...
cruiser54 Posted November 2, 2013 Share Posted November 2, 2013 Probably oughta test the CPS output. Manual trans? Ever refresh all the engine bay connectors? 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 I suggest unplugging EVERY electrical connection in the engine bay you can find, whether engine related or not, and spraying it out with a good electronics cleaner, visually inspecting the terminals making sure they haven’t retracted into the plastic holder, and then plugging it back together. There’s a critical 10-pin connector for the front lighting system located in front of the air cleaner and behind the left headlight assembly. Don’t miss that one . Also be sure that the connectors to the ballast resistor mounted near the air cleaner housing are clean and tight. ALL of the relays should be removed, the terminals wire-brushed until shiny, and the receptacles sprayed out with contact cleaner. Then plug them back in. I do this on every Renix Jeep I purchase or work on for someone else. Revised 07/23/2012 Link to comment Share on other sites More sharing options...
metrictonner Posted November 2, 2013 Share Posted November 2, 2013 My truck might be doing the same thing as yours. I haven't fixed anything yet but I've found that doing short cranking cycles instead of one long 30 second one fires mine up on the second or third cycle. I agree that pumping the throttle shouldn't do anything. It might indicate, however, that your TPS voltages need to be checked. Good luck. Link to comment Share on other sites More sharing options...
Eagle Posted November 2, 2013 Share Posted November 2, 2013 I'm more inclined to go with the CPS as the prime suspect. Another thing -- a 20+ year old fuel system may not hold pressure overnight. Do you turn the key to RUN and then wait until the fuel pump stops before trying to start the engine? If not, you're cranking the engine before you have adequate pressure in the fuel rail. Link to comment Share on other sites More sharing options...
carnuck Posted November 7, 2013 Share Posted November 7, 2013 corroded TPS can affect it too. Link to comment Share on other sites More sharing options...
HOrnbrod Posted November 7, 2013 Share Posted November 7, 2013 corroded TPS can affect it too. Any corroded electrical connection on the starting, ignition, and/or fuel system can cause hard starting. That's why Cruiser posts up detailed instructions for cleaning these system connections, connectors, and sensors up. Link to comment Share on other sites More sharing options...
carnuck Posted November 7, 2013 Share Posted November 7, 2013 I'm talking about inside the sensor. Pressure washing the motor can force it in and the cleaning chemicals eat up the windings (found that out the hard way. Less than a week after a brand new sensor on my '86 Comanche) Link to comment Share on other sites More sharing options...
HOrnbrod Posted November 7, 2013 Share Posted November 7, 2013 You pressure washed around the throttle body? Really? Link to comment Share on other sites More sharing options...
carnuck Posted November 7, 2013 Share Posted November 7, 2013 Washing the heavily greasy motor. Rookie mistake, My first fuel injected Jeep Link to comment Share on other sites More sharing options...
HOrnbrod Posted November 7, 2013 Share Posted November 7, 2013 Washing the heavily greasy motor. Rookie mistake, My first fuel injected Jeep Doesn't work well with carbed Jeeps either. Or carbed anything. Link to comment Share on other sites More sharing options...
carnuck Posted November 7, 2013 Share Posted November 7, 2013 Unlike water in electronics, you can usually dry off the dist cap, wires and some water remover in the carb bowl plus all the connectors under the hood cleaned and you're good to go. Link to comment Share on other sites More sharing options...
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