McHank

Good afternoon,

I'm a fairly new Jeep-owner who has run in to some issues with my 94 Cherokee HO. When first bought it started up and ran like new... sort of, but since last week it has decided to only start at random.

I was driving for about 45 mins when I stopped for a coffee. Coming out to start it up again it would only crank but not give any spark (tested the spark ). It's getting fuel no problem but the weird thing is that it does give spark on occation – especially after taking the dist.cap and rotor off and fiddling with the camshaft sensor (just putting a screwdriver between the magnet and the sensor – no idea if that does anything tho but more often than not it starts afterwards).

Today I decided to see if it would die on the freeway, but not only did it start without a hitch – it ran without a problem (so no shutting down while driving, never has) but when stopping and then trying to start – same issue, cranks but doesn't fire.

I changed the CPS (crankshaft p. sens.), the rotor and the dist.cap, also put in new spark plugs and tried with extra battery but to no avail.

The error code blink test gives me 12 (battery unplugged) and 54 (camshaft sensor), but could a camshaft sensor really be working this intermittently or could this be a problem starting at the PCM or maybe the relays?

I already threw a couple hundred at the problem and am a bit hesitant on the purchase of a new camshaft sensor (living in northen Europe these parts don't come cheap).

Any help on this issue would be greatly appreciated.

And thanks for a great forum.

//Hank

Slick761

Cmp sensor effects injector pulse. Sounds like a coil issue. Check for power to the coil. Check the coil with a multimeter make sure primary resistance is in spec. You can find instructions in the fsm or haynes/chilton. The thing in the distributor under the reluctor should be the ignition pick up.

McHank

Hi,

Thank you for such a speedy reply.

Just to be sure (english not being my first), is this the part you mean?:
http://www.genesisautoparts.com/web_images/IGNITION_COIL-ICA016.jpg

If that one goes bad, would the camshaft sensor start to freak out on occation?

edit. wrong pic in reference to how mine look.

edit.2 When checking the spark plugs today I noticed a fine white powder on all of them, as well as looking a bit burnt – could this be related?

Slick761

That is the coil yes. Should not make the cam position sensor freak out. If I were you I would just start by replacing the cam position sensor since its throwing a code. Unfortunately you have to remove the distributor to do this. I know my early Cherokee can run with a bad cam sensor but I don't think ours will. You can however test your coil. Make sure you have power in at the primary. Check for continuity at the primary and secondary. Im just saying don't just throw parts at it. If you know the Cmp sensor is bad start there. It's a pain in the *** if you've never pulled a distributor but you'll learn lots.

Slick761

Sounds like old plugs... are they blistered? If so its lean whig could be caused by the cam position sensor malfunctioning. Also be sure to clean all grounds from battery to engine and engine to body. Some people add an extra ground strap from battery to body.

McHank

Thanks again, but can't the sensor be changed without the distributor being ripped from it's placement? Underneath the dist.cap and rotor I have a round plastic plate with 3 wires coming out.

Being a novice, I have to ask, which is the primary and which is the secondary when it comes to the coil?

They look a bit blistered but they have only been driven for 3 - 4 hours, the white powder comes off and it looks ok underneath the coating.
I chacked all the ground today and I do have an extra one going from battery minus to the body (put it in front, on the beam right above the left headlight.)

Slick761

Think yours is different then mine on the Cmp sensor. Anyhow let's make it easy http://www.ehow.com/how_5997957_test...-cherokee.html

McHank

This is what my sensor looks like: http://images.oreillyauto.com/parts/.../acd/c1941.jpg

Its just underneath the dist.cap and it kind of just pops off.

Very useful link, I'll try to get a buddy (left it at his house when it died today) to test that prior to me getting the sensor – I find it too easy to throw parts at it when desperate to get it up and running.

Slick761

Ya I would replace that since you're throwing that code. try rockauto.com thy list it for 20$-40$. They have great prices. Listed under ignition as distributor ignition pick up. Probably will fix your issue.

McHank

That's pretty amazing, that part is about $100 here... The CPS was $220 – hence the reason of me not wanting to throw more stuff at it – without checking with people who know first (i.e this forum).

And another reason for me being hesitant is the fact that the error system gave me a 21 (O2-sensor) yesterday – but that would not affect starting, am I correct? Just worried that the cam-crank-o2 is connected somehow and the real culprit is the PCM?

Slick761

I just looked and ya you can replace the Cmp without taking the distributor out. I can't. Where are you located?

McHank

Great, that makes it easier since I'm not too keen on removing the distributor and with that the trouble of timing the whole thing (should do it sometime tho, just to learn).

Am in Sweden.

Slick761

Well good luck... ill be busy for a bit here hopefully someone else will chime in if you have questions.

McHank

Thank you for your input! Btw, what are you working on?

Slick761

Putting all new bushings up front and cleaning and greasing my superflex (rubicon express) joints. Also re painting everything