rugerwallace

my 87 is taking forever to start up!! this just happend lastnight after work got in and cranks good but takes like 4 or 5 tries to get it to turn over. So been in the garage with it still having the same problem.Once its warmed up it dosent take as long but what i have noticed is the rich smell of fuel upon it turning over. So with that being said Im hoping to get some info as i use my Jeep for my daily driver and need it for work. Thanks Guys

Gee oh Dee

Just curious...when was the last tune up done?

DFlintstone

I gotta run Bud...look at the CPS thing in my signature. Un-plug, re-plug it's connector. Check the little MAP tube from thr TB, back, and up to the MAP there on the firewall....and YES!,^^ plugs at .035?

rugerwallace

new plugs and wires 6mo ago cap rotor 1yr ago oil is every 3000 or less changed TPS 3 OR 4MO AGO IAC was cleaned to fuel injectors all new o rings like 3 mo ago fuel filter 1 1/2yr ago and i just took off my ingnition module and gave it a good cleaning

tjwalker

You have a Renix XJ (87-90) By design, the engine is not going to fire until the computer (ECU) gets a signal from the crankshaft position sensor and measures that signal to indicate that 300 rpms while cranking has been met/exceeded.

Somewhat extended crank times should be considered a “characteristic” of your engine, rather than a problem.

You can upgrade the battery and battery cables--at least 4 ga., 2 ga. better--and buy a high-torque starter.

Be sure that all grounds are good. Remove them and freshen them. You cannot tell if the grounds are electrically good by looking at them! Renix vehicles are very sensitive to ground issues.

Your CPS can be a bit weak, too. Unplug it and probe the two wires with your meter set on AC volts. You should get .5 as a reading. Anything down around .35 will cause long crank times and possible intermittent no-starts.

Other than that, performing basic tune-ups on a regular basis is important, (plugs, wires, cap, rotor, fuel filter) The importance of fresh secondary ignition (tune up parts) cannot be overstated.

Good luck!

cruiser54

Check the CPS output voltage per the folowing instructions. It may be on the way out. Report back your findings. Also a good idea to clean the C101 connector as the CPS signal travels through it. That write-up is provided below the CPS diagnostic write-up I'm posting for you .

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 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