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Old 11-19-2011, 06:22 PM   #1
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Default No start on 87 4.0L

My 87 Woody has been always slow to start. After parking it while we had house construction the old girl was not touched for 6 months.
Now that I have time to get back to XJ's the 87 with 4.0 auto will not start.
Put 5 gallons of fuel in.
I hear the Fuel pump kick on every third cycle of the key.
Sputters with a shot of starter fluid. ( I should have spark)
When I hit the fuel valve on the fuel rail I don't see any fuel spray out.
(I always thought you should have some)
I did replace the fuel filter last year.
The jeep is away from the shop, and I have not dug deep into yet.
My first step I thought would be to see if fuel sprays out after the filter.
Check the PSI at the fuel rail.
unplug the CPS
I'm am suspecting the CPS as it has always been very cold Nurtured.
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Old 12-27-2011, 10:50 PM   #2
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Giving the 87 some TLC.
I have it started but its seams cold nature. After sitting it takes three of four tries of the key to start it.
Once started it takes 5-6 rotations for it to start.
At First I suspected the CPS.
After looking how hard it was to get to I check the resistance. It was 212ohms. My Chilton manual tells me 200 +- 75ohms.

I cleaned the plug above the brake booster. Clean out tar and sealed it with dialectic grease.

Cleaned/ replaced the ground wire on engine block.

Checked coil for resistance readings Check out also per Chilton manual.
I have replaced the fuel filter.

Around 10 when cycling fuel pump
Fuel rail reads close to 40 PSI when cranking.
The fuel gauge reads full all the time.
( I need to check the ground for the fuel pump)
I am now suspecting something in the fuel line /pump
Like if it sits over a period of time it doesn't hold enough pressure? Bleeding off overnight?

Any other good info for slow starting Jeep?
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Old 12-28-2011, 05:47 AM   #3
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Check the CPS this way:

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
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An index to over 25 helpful write-ups is in Post #1.
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Old 12-29-2011, 11:34 PM   #4
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I tested my CPS. It was .30v AC.
I did buy a new a few days ago before most of this started.
So I dug into it. After lowering the trans support I was able to access the bolts with some odd combinations of twisting and cursing. Once I had them loose it went easy. I was so happy to remove the CPS. Now I have no idea what happen to the rubber cover that goes around the CPS. I'm almost positive when I pulled the sensor down nothing followed. The rubber has to be good size. I thought by some odd chance it could fall in the hole? I reached up inside the housing and could not feel it. What is the chance of it just dropping inside? Maybe the PO removed it and did not reinstall?
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Old 12-30-2011, 05:30 AM   #5
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I chuck those grommets. they rarely fit properly once removed anyway.

What kind of AC voltage is your new CPS putting out?
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Cruiser's Mostly Renix Tips can be found in the pink link below:

An index to over 25 helpful write-ups is in Post #1.
http://www.cherokeeforum.com/f51/cruiser54s-mostly-renix-tips-153657/

In Handy Printable pdf format:
https://docs.google.com/file/d/0Bz4d...aEE/edit?pli=1

A link to my Jeep Technical Photos:
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Old 12-30-2011, 12:32 PM   #6
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I have not yet put in the new CPS. I was looking all around the engine area for the the grommet. It was late and wanted some advice before further install. I'm thinking I must not of had it to begin with. I would seen it around the sensor. Does it really hurt any thing not to have it? Can you purchase a new one any place?
Before I started I blew all the mud off the bell housing and area. The PO mudded this thing heavy
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Old 12-30-2011, 08:02 PM   #7
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Sleep well tonight. Your Jeep will be fine without that confounded, ill-fitting grommet.
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Cruiser's Mostly Renix Tips can be found in the pink link below:

An index to over 25 helpful write-ups is in Post #1.
http://www.cherokeeforum.com/f51/cruiser54s-mostly-renix-tips-153657/

In Handy Printable pdf format:
https://docs.google.com/file/d/0Bz4d...aEE/edit?pli=1

A link to my Jeep Technical Photos:
http://www.cherokeeforum.com/g/album/1725214


Refresh*Connections*Before*Replacing*Components
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Old 01-01-2012, 08:35 PM   #8
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I had a chance today after the holiday to install the CPS. The new one was putting out 0.2Vac. O'rilley brand that had thinner gauge wires and shorter lead wires. So I drilled out the old CPS mounting flange. Installed the original after clean up. It also was now putting out 0.2Vac. Before I stated it put out 0.3Vac. It still takes a lot of cranking to start.
On average three tries with the key cranking. With 10 revolutions each.
I guess after 30 revolutions of the motor it has enough to build up an electromagnetic charge?

Does Napa really have better CPS than other stores?
How can I tell with out installing if it is really better?
Both my CPS are 208 ohms and 212 ohms.
Is it possible to clean the flywheel with anything?
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Old 01-01-2012, 09:00 PM   #9
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There's nothing to clean at the flywheel. Napa or the dealer should have better parts. At Napa, ask for a Premium CPS.
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Cruiser's Mostly Renix Tips can be found in the pink link below:

An index to over 25 helpful write-ups is in Post #1.
http://www.cherokeeforum.com/f51/cruiser54s-mostly-renix-tips-153657/

In Handy Printable pdf format:
https://docs.google.com/file/d/0Bz4d...aEE/edit?pli=1

A link to my Jeep Technical Photos:
http://www.cherokeeforum.com/g/album/1725214


Refresh*Connections*Before*Replacing*Components
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Old 01-01-2012, 09:03 PM   #10
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Have you ever cleaned out your C1010 connector? Lots of important signals run through it, including the CPS signal!!

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


__________________
Cruiser's Mostly Renix Tips can be found in the pink link below:

An index to over 25 helpful write-ups is in Post #1.
http://www.cherokeeforum.com/f51/cruiser54s-mostly-renix-tips-153657/

In Handy Printable pdf format:
https://docs.google.com/file/d/0Bz4d...aEE/edit?pli=1

A link to my Jeep Technical Photos:
http://www.cherokeeforum.com/g/album/1725214


Refresh*Connections*Before*Replacing*Components
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Old 01-01-2012, 09:13 PM   #11
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[QUOTE=cruiser54;1429810]Have you ever cleaned out your C1010 connector? Lots of important signals run through it, including the CPS signal!


Yeah I clean out the tar from the plug. Few shots of electrical contact cleaner and air hose. Spray, clean , air 5 times then dialectic grease.
I will get new cps and see what happens. If anything I have learned how to remove and install.

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Old 01-01-2012, 09:37 PM   #12
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I just read a thread where a guy had a booger of a time, turned out his fuel pump relay contacts sometimes where causing a problem. Cleaning the prongs on all if them with a wire brush and spraying out the sockets with contact cleaner is something I need to do. Anyway fuel is the third one back I think. http://autorepair.about.com/library/images/bl347lib.htm

Aldo Btw the ceramic resistor by the air cleaner, front gets full current, rear sends 9-10 volts to the fuel pump. (that can be by-passed, just makes the pump quieter)

You wrote "I have it started but its seams cold nature. After sitting it takes three of four tries of the key to start it. Once started it takes 5-6 rotations for it to start."

Around five or six is about what mine takes, just the nature of a Renix system.

Because the ECU kills the power to the pump after a couple seconds, sometimes I need to turn the key to ign and back off a few times to get up to pressure since mine is bleeding off somewhere, probably my injector(s), or maybe the check valve at the pump.

You got the top-notch guy here, in Cruiser, just wanted to add some details.
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87-90 Renix jeep owners. This is a link to great info! http://www.cherokeeforum.com/f23/tes...itings-136452/
The book's wrong! #1 is at 5:00, viewed from the side. 153624 clockwise.
I RECOMMEND 280 155 746 INJECTORS, FOR YOUR 87-90 JEEP. 4 holes are better than one, and they won't leak out the middle,(like stock injectors can)
"The problem is not that we have too many fools, it's that the lightning isn't distributed right." Mark Twain
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Old 01-01-2012, 11:12 PM   #13
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Quote:
Originally Posted by DFlintstone View Post
I just read a thread where a guy had a booger of a time, turned out his fuel pump relay contacts sometimes where causing a problem. Cleaning the prongs on all if them with a wire brush and spraying out the sockets with contact cleaner is something I need to do. Anyway fuel is the third one back I think. http://autorepair.about.com/library/images/bl347lib.htm

Aldo Btw the ceramic resistor by the air cleaner, front gets full current, rear sends 9-10 volts to the fuel pump. (that can be by-passed, just makes the pump quieter)

You wrote "I have it started but its seams cold nature. After sitting it takes three of four tries of the key to start it. Once started it takes 5-6 rotations for it to start."

Around five or six is about what mine takes, just the nature of a Renix system.

Because the ECU kills the power to the pump after a couple seconds, sometimes I need to turn the key to ign and back off a few times to get up to pressure since mine is bleeding off somewhere, probably my injector(s), or maybe the check valve at the pump.

You got the top-notch guy here, in Cruiser, just wanted to add some details.
I believe Cruiser has helped many people with the Renix system.
I wanted to get this thing worked great as things always work so much better in a heated garage. Away from the garage things just magically appear.
Tonight I was cleaning out the relays, and all electrical contacts around the battery. Ran a ground the fender to the battery. Just making it a little better dong some PM.
What's odd is I don't have white ceramic resistor on the driver fender. (87 waggy)
My 90 xj does.
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Old 01-01-2012, 11:38 PM   #14
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I saw posted that it was added when people complained of noise from the pump. Cruiser would know...wonder if some didn't have it in 87? Or somebody just caned it. If there are orange wires spliced there that's probably what happened.
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87-90 Renix jeep owners. This is a link to great info! http://www.cherokeeforum.com/f23/tes...itings-136452/
The book's wrong! #1 is at 5:00, viewed from the side. 153624 clockwise.
I RECOMMEND 280 155 746 INJECTORS, FOR YOUR 87-90 JEEP. 4 holes are better than one, and they won't leak out the middle,(like stock injectors can)
"The problem is not that we have too many fools, it's that the lightning isn't distributed right." Mark Twain

Last edited by DFlintstone; 01-01-2012 at 11:41 PM.
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Old 01-02-2012, 11:39 AM   #15
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I went to Napa, - no CPS available
Autozone order in
American in tomorrow

While looking at the available sensors some had high altitude sensors. (Order in Item) Is it possible a high altitude would be better?
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