'89 won't start HELP
02-27-2012, 03:13 PM
#1
Newbie
Thread Starter
Join Date: Feb 2012
Location: missoula, mt
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1989
Model: Cherokee
Engine: has one
'89 won't start HELP
I took my daughter to the store, Jeep was running fine, we came out and it won't start! It tries but just turns and turns w/No catch. I know nothing about cars other than what I've learned on here and Google. My manual is missing the entire chapter on the electrical system( of course). How can I easily check for fuel pressure or if it's the ignition? I'm a single mom, broke right now, so it has to be without buying pressure checkers or volt meters. Please help, please please please 
02-27-2012, 03:26 PM
#3
Newbie
Join Date: Sep 2011
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
I took my daughter to the store, Jeep was running fine, we came out and it won't start! It tries but just turns and turns w/No catch. I know nothing about cars other than what I've learned on here and Google. My manual is missing the entire chapter on the electrical system( of course). How can I easily check for fuel pressure or if it's the ignition? I'm a single mom, broke right now, so it has to be without buying pressure checkers or volt meters. Please help, please please please
02-28-2012, 08:14 AM
#7
Newbie
Join Date: Sep 2011
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by jensampson31
That's the one that runs along the back of the engine, right?
Trending Topics
02-28-2012, 04:45 PM
#8
CF Veteran
Join Date: Aug 2011
Location: Nor-Cal Coast
Posts: 10,489
Likes: 0
Received 17 Likes
on
17 Posts
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Hey! I found you...I still learning the message business. Yea, that CPS can be easy, the first time maybe not really.....pretty easy to check though. Do you have access to a digital meter? If not Harbor Freight has one that actually works for $5. OK, I just re-read, it might be really helpful if you could borrow a digital that reads AC volts.
Also do you hear the fuel pump run for about two seconds right after you turn the key to Ign?
If not, "jump" the ballast resistor (there on the inner fender by the air cleaner and try that again. (connect the orange wires).
Also do you hear the fuel pump run for about two seconds right after you turn the key to Ign?
If not, "jump" the ballast resistor (there on the inner fender by the air cleaner and try that again. (connect the orange wires).
Last edited by DFlintstone; 02-28-2012 at 05:00 PM.
02-28-2012, 05:43 PM
#9
CF Veteran
Join Date: Nov 2010
Location: In the middle of Minnesota!
Posts: 5,805
Received 99 Likes
on
88 Posts
Year: 1999
Model: Cherokee
Engine: 4.0
Jen, yes the crank sensor is certainly a primary suspect here.
What would be helpful is if you could check for spark. Pull a spark plug, keep it attached to the plug wire, place the spark plug electrode near a good engine ground, have a buddy crank the engine while you watch. You are looking for a strong, BLUE, snapping spark. Yellow/orange/white indicates a weak spark which may be a faulty ignition coil.
IF you have blue spark (and only if), then try a small splash of gasoline into the intake or a short shot of starting fluid. If the engine starts and runs using this technique, you have identified a fuel delivery problem.
And yes....as DFlintstone wisely mentions, you should hear the fuel pump energize and run for approximately 2 seconds when you turn the key to the ON position (not start). Is this happening?
The above three simple tests can help you isolate this so you are not throwing parts at this. Other than taking it to a shop, this is the absolute best advice I can give you and I assure you is the way I would proceed if I had your XJ in my garage.
Good luck and keep us updated!
What would be helpful is if you could check for spark. Pull a spark plug, keep it attached to the plug wire, place the spark plug electrode near a good engine ground, have a buddy crank the engine while you watch. You are looking for a strong, BLUE, snapping spark. Yellow/orange/white indicates a weak spark which may be a faulty ignition coil.
IF you have blue spark (and only if), then try a small splash of gasoline into the intake or a short shot of starting fluid. If the engine starts and runs using this technique, you have identified a fuel delivery problem.
And yes....as DFlintstone wisely mentions, you should hear the fuel pump energize and run for approximately 2 seconds when you turn the key to the ON position (not start). Is this happening?
The above three simple tests can help you isolate this so you are not throwing parts at this. Other than taking it to a shop, this is the absolute best advice I can give you and I assure you is the way I would proceed if I had your XJ in my garage.
Good luck and keep us updated!
Last edited by tjwalker; 02-28-2012 at 05:47 PM.
02-28-2012, 06:04 PM
#10
CF Veteran
Join Date: Aug 2011
Location: Nor-Cal Coast
Posts: 10,489
Likes: 0
Received 17 Likes
on
17 Posts
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Good advise above ^ as always...except, maybe YOU turn the key and have your buddy check the spark. (tell you why later). Here's all you might need to change the CPS, (but you want to check it first!). I'm not sure exactly how long the "long" is though. Might need only 18 inches. If your left forearm is smaller than a quart mason jar, its easier. (to reach up past the front drive-line)
02-29-2012, 11:33 AM
#13
CF Veteran
Join Date: Aug 2011
Location: Nor-Cal Coast
Posts: 10,489
Likes: 0
Received 17 Likes
on
17 Posts
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Ye-Haw, sounds like fun in Montana! 
A quick and easy test I might do right off if I had a problem. If you open the hood, there is a thing there called the fuel rail. You can identify it because there is nothing else under there you would want to call a "fuel rail", (it's right on top). Under the little cap with a thumb screw there is a Schrader valve. (like the air filler on a tire).
You could turn the key to on, then off and on again a few times, (you should here the pump, at least the first time),then depress the little delie, (as if you where letting air out). A small bit of gas should come out into the rag you're holdein there. If you did that cranking or running the chance something could go really wrong with fuel and a spark go way up!
Below is a writeup by cruiser54. Once I pushed the button on my kitchen timer, went out, opened the hood and did it, came back in and sat down. < three minutes! (is partly why I suggest anyone with a meter and Renix problem start there) (it's gotta be cranking OK)
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
A quick and easy test I might do right off if I had a problem. If you open the hood, there is a thing there called the fuel rail. You can identify it because there is nothing else under there you would want to call a "fuel rail", (it's right on top). Under the little cap with a thumb screw there is a Schrader valve. (like the air filler on a tire). You could turn the key to on, then off and on again a few times, (you should here the pump, at least the first time),then depress the little delie, (as if you where letting air out). A small bit of gas should come out into the rag you're holdein there. If you did that cranking or running the chance something could go really wrong with fuel and a spark go way up!
Below is a writeup by cruiser54. Once I pushed the button on my kitchen timer, went out, opened the hood and did it, came back in and sat down. < three minutes! (is partly why I suggest anyone with a meter and Renix problem start there) (it's gotta be cranking OK)
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
Last edited by DFlintstone; 02-29-2012 at 12:15 PM.
02-29-2012, 11:47 AM
#14
CF Veteran
Join Date: Nov 2011
Location: phoenix az
Posts: 1,290
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1989
Model: Cherokee
Engine: 4.0l 6 cylinder
Originally Posted by DFlintstone
Ye-Haw, sounds like fun in Montana! A quick and easy test I might do right off if I had a problem. If you open the hood, there is a thing there called the fuel rail. You can identify it because there is nothing else under there you would want to call a "fuel rail". Under the little cap with a thumb screw there is a Schrader valve. (like the air filler on a tire).
You could turn the key to on, then off and on again a few times, (you should here the pump, at least the first time),then depress the little delie, (as if you where letting air out). A small bit of gas should come out into the rag you're holdein there. If you did that cranking or running the chance something could go really wrong with fuel and a spark go way up!
Below is a writeup by cruiser54. Once I pushed the button on my kitchen timer, went out, opened the hood and did it, came back in and sat down. < three minutes! (is partly why I suggest anyone with a meter and Renix problem start there) (it's gotta be cranking OK)
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
A quick and easy test I might do right off if I had a problem. If you open the hood, there is a thing there called the fuel rail. You can identify it because there is nothing else under there you would want to call a "fuel rail". Under the little cap with a thumb screw there is a Schrader valve. (like the air filler on a tire).You could turn the key to on, then off and on again a few times, (you should here the pump, at least the first time),then depress the little delie, (as if you where letting air out). A small bit of gas should come out into the rag you're holdein there. If you did that cranking or running the chance something could go really wrong with fuel and a spark go way up!
Below is a writeup by cruiser54. Once I pushed the button on my kitchen timer, went out, opened the hood and did it, came back in and sat down. < three minutes! (is partly why I suggest anyone with a meter and Renix problem start there) (it's gotta be cranking OK)
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
02-29-2012, 11:59 AM
#15
CF Veteran
Join Date: Mar 2011
Location: California
Posts: 2,570
Likes: 0
Received 4 Likes
on
4 Posts
Year: 1992
Model: Cherokee
Engine: 4.0 HO
x-whatever on the CPS. I'm originally from Missoula, if you need some help figuring it out I have a few jeep friends out there still.