Error codes 12-43-43-11-55

L

lapisxj

NAXJA Forum User
Location
Huntsville, AL
I know there isn't supposed to be any duplicates but I've run it 5 times now and it looks like 43 trips twice. 96 model 215k miles on the stock 4.0 runs fine on the road but offroad and under a load (hard push up hills) it will start running like poo and trip codes. After searching on here a bit I'm thinking a few routes to start down. Check fuel pressure, check EGR valve, and check plugs.

I pulled what I think is the EGR valve (pass side of throttle body) and the piston won't push in at all or is very stiff. It wasn't overly cruddy. Is there a voltage or resistance I need to look for? Why can't I find one of these online for this rig?

I don't have a fuel pressure gauge so I can't check that just yet. Plugs I'll probably pull tomorrow.

I know 12 and 55 are no problems but what do ya'll say about the others?

HELP, I'm headed to MOAB in 11 days. Got to get this fixed on top of all the other stuff I have to do.
 
You don't have an EGR valve. Most likely the part that you pulled off was the IAC, put it back. You are on the right track with the fuel pressure and plugs. What have you done to it in the past? Have you replaced the CPS? Has it been hard to start? Have you disconnected sensors and tried to start it? The code 11 would point to the CPS which may cause your symptoms. My advice would be to clear the codes, recreate the symptoms and then pull the codes again. If code 11 shows up again look into the CPS and wiring to it.
 
The repeated 43 means you have misfire on more than one cylinder. Go visit your local Autozone and borrow a reader to pull the OBDII codes to find out which. Then quickly leave in case the counter jockeys try to sell you something of crap quality for the wrong vehicle.

Note that the code 11 indicates a bad Crank Sensor, which might actually cause the misfire codes. Code 11 is thrown when the camshaft sensor is showing rpm, but the crank sensor isn't showing a signal. Under load could mean higher temps on the crank sensor and its failing? I'm thinking you might want to at least pack a spare CPS sensor for the trip.
 
CPS is on the driver's side on the top of the bellhousing

IAC= Idle air control, it controls the amount of air bypassing the throttle plates to increase idle speed.
 
BTW, do a search on changing the CPS, it can be a real PITA to replace. PS, be careful not to drop the bolts in the bellhousing!
 
Update...

Well I replaced the CPS and wow I was supprised at how easy a job it was. I had read all these writeups and was dreading the task but it wasn't that bad. My method was to have a shop light from the engine side shining down to back-light the sensor then came at the bolts from the bottom with a 7/16" socket, wobble, and a few extensions on a ratchet. Old one popped out and the new one went right in. Took the top bolt out first and put it back in last. Hardest part was grabbing the bolts and getting them started again but overall the job was 20 minutes.

I cleared the codes and it drives fine but I'm curious if I've really fixed it or not.
 
Well that didn't fix it. :gonnablow

Drove it to work and it ran fine. Took it out for a test run at lunch and it started acting up again. I drove about 10 min from work till I hit the base of one of the mtns here in town. Hit the gravel and started powering up the gravel roads that wind around the mtn, about 10 min worth of hi-rev, wheel spinning, power sliding driving. Got to the top, shut her down, ate lunch, and when I cranked her back up it ran like poo. Popped the hood, messed around with a few sensor plugs (no luck), rev'd it up a few times, got back in and I had a Check Engine Light waiting on me. Codes 12-43-55. WTF?

I leave for Moab in 2 days. HELP!
 
Did the CKP (CPS) harness get against the hot manifold?

Try unplugging the CKP and plugging it back in.
 
The old one didn't have any signs of getting close to the manifold and I know the new one isn't anywhere close.

Forgot to mention that as I was coming back to work it ran fine.
 
I guess I would start with cleaning all cable ends and renewing all grounds. Go through the sensors and check the connections, maybe a little dielectric grease.

Hope you have a great time at MOAB.
 
Sounds like when you ate lunch-something got heat soaked. -Might try that 'pouring some water on the crank sensor' test. Also wiggle the fuel injection wiring to see if it will clear while running bad.
 
Check the Front temperature sensor, near thermostat, connection, wiring, and ground. It would heat up at shut down and cool off when running again, and send bad info to ECU.
 
When was the last time you looked at the under side of the distributor cap? The bushings in the dist may have too much slop and the spark is going someplace else.
 
Alright, I'm off to buy a temp sensor, dist cap, and a fuel filter. May get a set of plugs too. I'll sort out what works (hopefully something) later. Don't have time to do much more than throw parts at it right now.
 
The bushings are different than the cap. Check the shaft in the distributor with the cap off to see if it has slop. I had an old Suburban with that issue. If you don't have time to do much, you don't have time not to diagnose. You're wasting time throwing parts.
 
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