This weekend I cleaned out the throttle body and the idle air control valve because the engine was idling pretty high on e in awhile and I figured it was because that valve was sticking! I also replaced all the orings in my fuel injectors which caused me to remove the fuel rail etc... Well in the midst off all that some of my vacuum lines snapped (it was 4 degrees outside, stupid I know) so patched up the vacuum lines and attempted to start the engine and I get nothing! I k ow the fuel pressure up to the injectors is in spec but the engine isn't even trying to crank over! I thought I may have heard a vacuum leak while trying to start it but I wasn't sure. Can any of the vacuum lines cause this problem? It worked fine before I started working on it but the only thing that went wrong was the snapped vacuum lines! Please help! The engine is the 4.0l inline six from 1987

 

You said you patched up the lines? With what? My suggestion would be to just replace them cause any patch job will not hold up as good as a new lines

 

I ordered new hoses and such I was just hoping someone could. Erich that the. Acuum system would prevent the engine from attempting to crank over. I can hear the fuel pump turn on and everything...

 

So when you turn the key nothing happens? The starter doesnt engage the pull-in and hold-in windings so theres no cranking action? If this is the case I'd start at your ground cable for your starter or any connections you may have been near. The vacuum system would not prevent the engine from cranking. Check all your connections, especially at the battery. This is step one. The starter draws a lot of current (amps) to engage the armature in the starter. poor connections will not allow it to work properly.

 

to branch off what Jeepin said, we need to clarify what you mean. You said it wouldn't start then later you said it wouldn't even crank. Well those are two seperate issues. Which is i. If it won't crank then that means when you hit the key it does nothing. The starter will not even turn the motor over, or "crank it". Now if the motor is spinning but won't start then that a different fix. Based on you are saying I am assuming it will crank but not start. If this is whats happening I would look closer into your vacuum lines. Now if in fact it will not even crank, its something electrical. Being that everything worked before you started "repairing it" (sorry I had to give you a little jab for that. Been there done that, not fun!)I would trace my steps. Did you remove the battery cable before you started? Did you get it back on correctly? If you didn't remove it did you do something that may have possible drained the battery? Just throwing stuff out there for ya.

 

So the engine does not even crank so I am going to check the cabling around the starter something must of gotten disconnected I will look today

 

Do you have interior lights and seatbelt buzzer when you insert the key? If this happening you are getting some current from the battery. If they appear dim or weak try charging the battery or giving it a jump from another vehicle. If none of this is going on then either your battery is completely dead or there is a bad connection with a cable.

 

Well he did mention he can hear the fuel pump turn on so i assume he has some power. But a poor connection can still turn those parts on and lead to starter failure.

 

Check for power at your stater relay if your not u have a probelm

 

Well it turns out it was the connectors to the starter!! came home and tried it this afternoon and she fired right up! Thanks for all the help....

 

Do make sure that you ended up with that little tube from the TB, back to the MAP on the firewall in good shape. (could flood if that is not giving the MAP good vacuum). Also I want to post some of Cruisers stuff for (up to 90) Renix Jeeps. (89&90 probably don't have the C-101)




Renix Jeep C101 Connector Refreshing
　
The C101 connector on 1987 and 1988 Renix Jeeps was a source of electrical resistance when the vehicles were new. So much so that the factory eliminated this connector in the 1989 and 1990 models. The factory recommended cleaning this connector to insure the proper voltage and ground signals between the ECU and the fuel injection sensors. We can only imagine how this connector has become a larger source of voltage loss and increased resistance over a period of almost 25 years. The C101 connector needs to be cleaned at least once in the lifetime of your vehicle. Chances are it’s never been done before.

Almost every critical signal between the engine sensors, injectors, and the ECU travel the path through the C101.
The C101 is located on the driver’s side firewall above and behind the brake booster. It is held together with a single bolt in it’s center. To get the connectors apart, simply remove the bolt and pull the halves apart. You will find the connector is packed with a black tar like substance which has hardened over time.
Take a pocket screwdriver or the like and scrape out all the tar crap you can. Follow up by spraying out both connector halves with brake cleaner and then swabbing out the remainder of the tar. Repeat this procedure until the tar is totally removed. This may require 3 or more repetitions. Wipe out the connectors after spraying with a soft cloth.
If you have a small pick or dental tool tweak the female connectors on the one side so they grab the pins on the opposite side a bit tighter. Apply a true dielectric grease, not the stuff that came with your brake pads, to the connection and bolt it back together.
　
　
Revised 11-29-2011





Renix Jeep ICU/Coil contact refreshing
　
　
The contacts between the coil and the ICU on your Renix Jeep can become corroded and loose causing a complete or intermittent no-start condition. I recommend the following procedure as a maintenance precaution to insure this is eliminated as a possible cause now and in the future.
The coil is attached to the ICU by two T20 Torx bolts. Remove these two bolts and lift the coil up off the ICU. You will see 2 pins and 2 sets of contacts. Clean both the pins and springy contact pieces with a good electronics cleaner.
Squeeze the springy contacts closer together with some needlenose pliers. Apply some dielectric grease to the contacts and bolt the coil back on to the ICU.
While you’re right there unplug the connectors from the ICU and inspect the pins in the harness connector. Make sure the pins are not retracted into the connector. Spray out the connector and the receptacle of the ICU with the same good electronics cleaner you used earlier. Apply dielectric grease to the connectors and plug them back in.
I feel this procedure should be performed at least once in the lifetime of a Renix Jeep.
　
Revised 11-29-2011
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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 it’s mounting holes with the first drill bit that just won’t fit through the original holes. Then, when mounting it, hold the CPS down as close to the flywheel as you can while tightening the bolts.
　
Revised 11-29-2011


Renix Ground Refreshin
The Renix era XJs and MJs were built with an under-engineered grounding system for the engine/transmission electronics. One problem in particular involves the multiple ground connection at the engine dipstick tube stud. A poor ground here can cause a multitude of driveabililty issues, wasted time, and wasted money replacing unnecessary components.
The components grounding at the dipstick tube stud are:
Distributor Sync Sensor, TCU main ground, TCU "Shift Point Logic", Ignition control Module, Injectors, ECU main ground which other engine sensors ground through, Oxygen sensor, Knock Sensor, Cruise Control, and Transmission Sync signal. All extremely important stuff.
The factory was aware of the issues with this ground point and addressed it by suggesting the following:
Remove the nut holding the wire terminals to the stud. Verify that the stud is indeed tightened securely into the block. Scrape any and all paint from the stud’s mounting surface where the wires will attach. Must be clean, shiny and free of any oil, grease, or paint.
Inspect the wire terminals. Check to see that none of the terminals are crimped over wire insulation instead of bare wire. Be sure the crimps are tight. It wouldn’t hurt to re-crimp them just as a matter of course. Sand and polish the wire terminals until clean and shiny on both sides. Reinstall all the wires to the stud and tighten the nut down securely.
While you’re in that general area, locate the battery negative cable which is fastened to the engine block just forward of the dipstick stud. Remove the bolt, scrape the block to bare metal, clean and polish the cable terminal, and reattach securely.
Another area where the grounding system on Renix era Jeeps was lacking is the engine to chassis ground. There is a braided cable from the back of the cylinder head that also attaches to the driver’s side of the firewall. This cable is undersized for it’s intended use and subject to corrosion and poor connections at each end.
First off, remove the cable end from the firewall using a 15mm wrench or socket. Scrape the paint off down to bare metal and clean the wire terminal. Reattach securely.
Remove the other end of the cable from the rear of the head using a 3’4" socket. Clean all the oil, paint and crud from the stud. Clean the wire terminal of the cable and reattach securely.
A suggestion regarding the braided cable:
I prefer to add a #4 Gauge cable from the firewall to a bolt on the rear of the intake manifold, either to a heat shield bolt or fuel rail bolt. A cable about 18" long with a 3/8" lug on each end works great and you can get one at any parts store already made up. Napa has them as part number 781116.
A further improvement to the grounding system can be made using a #4 cable, about 10" long with 3/8" terminals at each end. Attach one end of this cable to the negative battery bolt and the other end under the closest 10mm headed bolt on the radiator support just forward of the battery. Napa part number 781115.

 

No problem bud! Always try to start at the most simple things then work from there

 

I couldn't get my 89 renix to fire checked all the sensors last thing continuity tested the wires to the CPS D1 and C1 one of them was only half way in not locked bent the tab installed the computer again it fired right up. Now when I give it gas it pukes. I need to by pass the TCu since I don't have the AW 4.

Any help on this would be appreciated.

I joined Monday before I went through the cost of new parts and it paid off with the info of checking everything first. Great site.

 

Click on the "pink link" in my signature and spend some quality time with your Renix Jeep.

 

Also take a good look at the wiring from your injector harness to the lower sensors. (knock, temp, & 02). Mine chafed/grounded and would do that, and backfire out the air-box. Shot the mouse and his nest in there right out the front grille. I then drove through confetti!