Topic: Ignition Problems

[CT-Rich]

Hey guys I hope someone here can help
I have a 95 YJ 2.5 5spd
Lately my ignition has been cutting out intermittently and when I get the ECU codes
it reads 12 12 12 13 14 11 13 11
I have replaced the map,speed,throttle position sensors and the distributer pickup.
I am starting to think that it is the ECU
Even though I get code 12, disconnect battery, I haven't disconnected it in quite a while

Thanks for any input

[Jeffy]

Are you sure it's giving all of those codes?  It should not show dupe codes and they should be in order.  The end code should always be 55.  The beginning code should almost always be 12 as well.  I would wager that there should be a 33 in there someplace as well.

[CT-Rich]

yes there was a 33 but I am still having some trouble reading the codes
I know there should be a 55 at the end but it doesn't seem like it
I will have a friend look at it later and let you know
I don't have A/C by the way, so does this mean there's a wiring short somewhere
in the harness?
thanks

[CT-Rich]

forgot to mention I replaced the O2 sensor not long ago as well

[Torch_Ind]

not having a/c will auto give you the code.

I have the exact same thing happen to me and found the auto shut off relay was corroded and got to the point it would not start one morning. check there first I also have wiring diagrams for the yj if you need some. also check the coil plug they sometimes have a bad connection and vibration and bumps can cause it to stall.

[CT-Rich]

Thanks I'll check it out tomorrow
There is also a new coil and high performance wires

I've been spending 2 years replacing parts on this thing in hopes it will be reliable?? someday
Actually it's been great, maybe some problems from time to time but it always gets me home

[VA_YJ]

I had a similar problem.  It turned out to be the wiring harness connector to the coil.  Try shaking wires while the engine is idling: if it sputters, you may have a bad connection somewhere.  Check the grounds (firewall and engine block) - make sure the connections are clean.  Swap out the horn relay for the ASD relay.  Make sure the multi-pin connector to the ECU is OK (pins clean and not bent, properly torqued - see FSM).  You can test the crank position sensor as well - make sure the CPS wires are not touching the exhaust.

Normally, when the ECU goes bad, starting is affected  The capacitors break down.  Your problem does not sound like a typical ECU failure, but it is possible.  I feel your pain - don't give up.  I have more info if these things don't locate the problem.  You can run some tests on the ECU connector using a meter to help locate the point of failure.

[Torch_Ind]

I also had the coil connector problem to but that was quite a while ago for me

[CT-Rich]

OK guys I'm just getting back to it , I was sick last week.
I replaced the Auto-shutdown relay and fuel pump relay today and I measured all
the grounds from the battery to the firewall and to the block, all ok.
I just got back from a test drive and after 10 min of warming up and 5 min of driving it started
again. A little loss of power near 3000 rpm then a backfire then ok.
This was on a flat road, then it started losing power up a hill. Can the CPS cause this?
I will go out and check the connections and harness and see what happens.

here is a picture of it
http://s419.photobucket.com/albums/pp277/RichardO_02/Jeep/?action=view&current=IM000317.jpg

[Torch_Ind]

how does your cap and rotor look? plugs? also sounds like it might be your coil dieing under load possibly. also have you check fuel pressure make sure it's not a fuel delivery problem?

I had some wierd problems with mine for a long time till I found out my return line was pluged in the tank from hitting a rock and it pushing my gas tank shield up against the fuel level sender and was causing up to 80 psi in my line.

[CT-Rich]

New coil last week even though the old one was 1 year old when I replaced the plugs,
Live Wire Plug Wires, a Screamin' Demon Ignition Coil and a Firepower Cap and Rotor
I tried moving the harness and I couldn't get it to stumble. Every sensor is less than 1 year
old except the crank position sensor.

I'll head out later and order a CPS, can't hurt except if I half to install it in the snow tomorrow.

Also, in the Haynes manual it say the 95 2.5L has no ASR relay and the 4.0L does, but it it there
and I'm not sure if I have an ignition control module or not, the manual doesn't show one and
Advance Auto Parts does not show one but people  on the boards talk about them.

Thanks for all the input guys

[CT-Rich]

I forgot to mention last summer I replaced the fuel pressure regulator and force air through
the return line to make sure it was clear. Fuel pressure was a little high about 48psi if  I remember
correctly.