r.center

One weekend I drove 500 problem free miles, the next morning, I went out to start the jeep and all it did was crank and crank. I did some research and I,dont think it is the nss because it does crank, although reverse lights dony work, and I dont think it is the cps, it cranks whether plugged in or not as well as working guages.

It gets a ton of fuel at the rail, I replaced the coil and wires (havemt done the plugs yet).

It sounds like it wants to start... With an occasional rumble... It doesnt do this with the main wire unplugged from the coil (obviously, but it may help diagnose)

Could it be the injectors?

I really dont think it is the fuel pump because after cranking for a while there is a strong gas smell.

Any help would be appreciated!

highmileage

you will still get a no start with a really dirty CPS, but will try to turn over. you have air fuel and fire just not enough fire getting there.

cruiser54

Here's how to check your CPS for the proper output voltage. start there.

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

DFlintstone

X2^. I once did that test in just a couple minutes with a $5 meter from Harbor Freight. Was around .3. Got an Echlin from Napa, and now it starts/run's great at around .5 (1/2 a volt AC)

stev-o

Cps for sure I'd say always happens

r.center

So I installed the new cps, and this thing still won't start.

The only thing that comes to mind is that when I installed the new c p s I didn't put pressure on the top while bolting it in. The plug somehow got grease on it. I tried testing it with a volt meter today, but I left my voltmeter outside in the rain, causing it to tweak out (I'm an idiot).

It does seem like it is trying to start more frequently with the new cps.

Please don't tell me I have a blown engine.

stev-o

Were do u get blown engine out of messing up the cps

highmileage

MAP sensor maybe......... it is kinda barometric and if you were up in the hills or in the lowlands it may have gotten stuck (broken) and this will cause a rich fuel and a no start. or it may have come unplugged

DFlintstone

I'm really sorry you went and spent money on a new CPS, then did that miserable job, all for nothing. I can't imagine why. Anyway, Renix will cut off the fuel from the injectors if you floor it while it's cranking, then start if it was flooded. Easy enough to try. And X2^, Map & fuel....Make sure its hooked up and the little tube from the rubber plug on the inside of the throttle body up to the MAP is A1. If it's cracked, off, or plugged that will make the MAP dump extra fuel. Also check/gap or change the plugs! (try it before you pull one to see if it's wet.) Then check spark.

And, yea, I noticed the cheap meters at least, die if there is even rain in the forecast! $5 at Harbor Freight and you can start over, with checking your new CPS. You might try pulling the battery and the cover and letting it get good and dry, sometimes works. (anything like that you pull the battery immediately, preferably without it having been on). Tough to test much without one I guess.

You should have listened to Cruiser!

cruiser54

Test. Don't guess.

eeprocker

I just spent two months trouble shooting what sounds to be the same issue. I would check that cps again it is probly fine but best to know for sure.

Then are u getting fuel? are you getting spark?

I wasn't getting fuel traced out the whole fuel sytems replaced the twice turns out all are good once i tested them

End of the line was I had a bad connection on my ballast resistor.

You should test your resistor test your relay and check your conectors if they are corroded at all snip it off and put a new one on. I tried scraping mine and it didn't solve it after I rand a hot wired directly to the fuel pump i discovered that's where the fault was new conector and it starts right up now

Also a good idea to check all your relays.

IF the problem is your not getting fuel that's where you should look there really isn't as much to the system as it seams.

If you are getting fuel check to see if you are getting sparks.

BTW I also got a point 3 reading on my old cps went ahead and replaced it wasn't the answer and i had the same concern u did so i don't think it's a problem but if you wanted to you could always pull it back out clean it up. and put it back in not to confident that will give you any reward though

cruiser54

[QUOTE=eeprocker;1675936]I just spent two months trouble shooting

End of the line was I had a bad connection on my ballast resistor.

You should test your resistor test your relay and check your conectors if they are corroded at all snip it off and put a new one on. I tried scraping mine and it didn't solve it after I rand a hot wired directly to the fuel pump i discovered that's where the fault was new conector and it starts right up now


Lots of this ballast connector crap happening lately, huh? Just happened to me.

DFlintstone

Did you ever check for spark? I see you changed the coil so it looks like you might have a spark issue. Of course that would be about the first thing to check if it won't start. I too had issues at the ballast resistor. I looked at it as soon as I didn't have fuel at the rail. Since you DO have fuel at the rail, and presumably can hear the pump run a few seconds when you first turn on the ignition, that likely is not your issue. (very easy to check anyway though, about 7 to 10 volts out the rear to the pump while it's cranking). (You can bypass it and put full voltage it the pump if you like)

Cruiser, Is holding the throttle floor-boarded and cranking it a way to rule out flooding caused by the MAP, or ether the incoming air or engine temperature sensors telling the ECU to dump extra fuel?

R.center. If you have a good strong spark you might consider the test below. TERMINAL "A" ON THE DRIVERS SIDE IS CRUCIAL. If it's not a near perfect ground (around 1 ohm resistance or less), you need to stop and see that it is. Crusier has a great write-up on that.

And again, make sure the vacuum line to it is A-OK. The line gets old and brittle and could cause your problem if it's off, cracked, or plugged up!


Manifold Absolute Pressure Sensor (MAP)
MAP sensor.

Located on driver side of firewall just behind & above engine.

Located on firewall behind valve cover. To test, using a voltmeter with the ignition on/engine off, voltage at terminal B should be 4 - 5 volts. The voltage should drop to 1.5 - 2.1 volts with a HOT, neutral idle engine. Supply voltage can be checked at terminal C with the ignition on. Voltage there should be 5 volts + or - 0.5 volts (Terminal A is the ground wire).

> What does it do? Compares ambient barometric pressure during start-up (cranking) to engine load while engine is running. The ECU computes that information and adjusts the air-fuel mixture accordingly.

Gee oh Dee

I would shoot some starting fluid into the intake directly.

If it fires, its fuel. If not, its spark.

DFlintstone

Great test^, unless it's flooded. Gave me fit's once on a friends Volvo. Great spark, would chug once or twice first thing, then nothing would help.....plugs where about dripping.

Just wanted to add, thinking about it I suppose I should have tried disabling the pump just to get'r goen. Seemed to work fine warm.