cruiser54

Try this: http://snowboard247.blogspot.com/2005/0 ... -info.html

Thanks for posting the part numbers. Sometimes the parts people have trouble finding our vacuum harnesses.

You don't mind if I snag your photo, do you?

The manifolds work fine. The intake ports are only off by about 3/16" and the exhaust ports are identical. We're not dealing with Formula One engines here. Use the intake/exhaust gasket for which ever intake manifold you use.

You will be fine. Use your 96 flexplate, distributor, manifold etc. As for the knock sensor when doing the swaps, the early HOs have the threaded hole for it and even the later ones have the hole but un-threaded. No big deal I've done 3 of these swaps with no issues.

Do not forget that ground strap on the firewall to the head. It's a weak point and much of your fuel injection system relies on it for a ground path. Me, I would replace it with a ground cable. But, you need to do as an absolute minumum: Remove each end, clean it's mounting point til shiny, clean the terminals and reinstall. You must scrape the paint off the firewall mounting point.

2 revised write-ups to replace the earlier first drafts I posted in this thread. Renix Ground Refreshing 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. If you want to upgrade your grounds and battery cables in general, contact Jon at www.kelleyswip.com. He makes an incredible cable upgrade for a very reasonable price. Revised 11-28-2011 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

On your 88 it's pretty easy. A 9/16" or 5/8" wrench is all that's required along with 3 seals from the dealer for under $10.

There were 126 of them on the day before thanksgiving.

Get a can of throttle body cleaner and spray where the intake manifold meets the head , throttle body bolts to the intake manifold, and around all the vacuum lines. When you spray on a vacuum leak, you'll know it. I have a write-up on TPS adjustment and testing, C101 connector cleaning, and another on ground refreshing if you want them. The ground refreshing needs to be done as does the C101 refreshing at least once in a Renix MJ's or XJ's lifetime. The grounding system and connectors in the harness on these Jeeps caused many issues that were blamed on faulty sensors that are costly to replace.

1987 and 1988 had the C101 connector. It's mounted in the engine bay above the brake booster, on the firewall. The two halves of the connector are held together with a bolt in the center.

Do the grounds first. Trust me. I was Service Manager and Shop Foreman at a Jeep dealership when these things were new. I kept a diary of sorts regarding prominent issues during that time. That's what I'm sharing in my first post-tried and true repairs for known problems. Little bit of time and no money buys you insurance for fewer problems in the future.

Been done. Read about it on NAXJA or JeepForum. Not for the faint of heart.

First thing to do when acquiring a Renix Jeep: Renix Ground Refreshing 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 terminations 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 terminations. Inspect to see that none of the terminations 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 meta, clean and polish the cable termination, 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 termination. 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 16’ long with a 3/8” lug on each end works great and you can get one at any parts store already made up. If you want to upgrade your grounds and battery cables in general, contact Jon at http://www.kelleyswip.com. He makes an incredible cable upgrade for a very reasonable price. I have 5 or 6 other write-ups on the Renix that you may want to check out after doing the ground refreshing. They are all intended to address known factory issues and prevent issues down the road, and save you money from buying unneeded parts. And, they're free. Here's another thing you'll want to do for sure: Renix Jeep C101 Connector Refreshing The C101 connector on 1987 and 1987 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 to the connection and bolt it back together.

That hose IS NOT a vacuum hose. It supplies warm air to the intake when it's really cold outside. Got a flashlight handy? Take a look at the leak in front. Is it coming from above the oil pan? If so, it's the timing cover seal. Replacement requires special tools like a puller. You would be best off having a shop do it if it's needed.

I'm not as savvy on the throttle body 4 cylinder injection systems as I am on the 4.0s, but here are a few things I would check. CPS output. Fuel pump relay. TPS. And make darn sure that braided strap from the back of the head to the firewall is in good shape. Be sure to remove it from the firewall end, scrape the paint off the attaching point on the firewall, clean the eyelet and reinstall.

That torn hose will not cause any driveability problems or rough idling. It's just there to provide warmer air on cold start-ups. The leak you see is from behind your front crankshaft dampener, aka front timing cover seal.

Carb? You should have throttle body fuel injection.

I understand that some aftermarket companies still offer them. The problem has been the unknown quality of the off-shore sensors, their high failure rate, and how often they're bad right out of the box because they don't generate a strong enough signal..

RENIX CPS ALERT High altitude CPS for Renix has been discontinued by Chrysler. The part number is 53005421 and using this CPS advances your ignition timing about five degrees . There are only about 120 of these available in the US as of November 23, 2011. Dealer price is around $50.

Check it out scientifically: 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 3.5 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. And see if this helps: 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.

Yeah but I'm wondering just how sophisticated the '88 systems are? The original owner rebuilt the engine in mine 10 years ago and apparently retained all the original sensors. Even if he had replaced all of them at the time of rebuild (I'm certain he did not) they still had age on them in spite of only having 5K miles on the engine. So I started out with none of the sensors working except the intake pressure sensor. The only sensor that effected running temp directly and was the IAT. Cooling system is new with constant electric fan and temps consistently 5-8 higher across the driving range than prior to sensor changes. After new cooling system the temp gauge remained buried at 190 regardless of rpm/driving condition. It is my conclusion the the one sensor with the most effect on fuel trim was the IAT. I did this on an 87, 88 and 90.

Check to see that the blend air door below the passenger side dash is closing fully. It's adjustable via a cable clip at the door itself.

I've done 3 of them. You are correct about the O2 sensor trimming the fuel via the ECU. But the ECU also uses IAT input for ignition timing. Colder air temp=more advance.

Crusier gets the prize! Crusier, I don't know what town you live in, but if I'm ever there I will buy you a pitcher of the beverage of your choosing. Prescott, Arizona and we have our own brewery!! LOL