Novak Conversions Jeep Wrangler TJ radiator

Suspected OPDA, limp mode, CEL and code clearing?

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JP_in_STL

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Do I need to clear the CEL and codes in order to exit limp mode?

New to me Jeep of about 3 months, 130K on it. Had limp mode, ran like crap, noisier and was on the interstate. I had to run about 20 miles in limp mode to get somewhere to pull off. Def noisier on the pass side of engine, but it was pretty hot from running lean. Googled on the phone, seems like an OPDA so I had the Jeep towed home. I've had a slight miss that I thought was a dirty fuel injector issue.

So this evening I sourced a Dorman OPDA, all I could get local. I carefully turned the cranked with a ratchet and a cheater until the holes lined up and slipped an awl in it. Pulled the current OPDA, also a Dorman. Checked the oil pump drive, looked at the cam teeth, clocked the new OPDA, and slid/rotated it in with no issues. All looked good and seemed fine. I don't have a scan tool to do a relearn (on order) but I pulled the battery cables for a reset. Fired it up and let it idle for 5 mins. Still has a CEL, went for a drive and I'm still in limp mode? So do I have to clear the code 1st to exit limp mode?
 
Disconnect the battery and wait 30 minutes. You didn't wait long enough. The CEL should clear.
 
mjbcomp said:
Disconnect the battery and wait 30 minutes. You didn't wait long enough. The CEL should clear.
Click to expand...

So I have to clear the CEL 1st, before I can exit limp mode? Or will it exit limp mode on its own. I learned the 3 key trick for pulling codes and all that currently shows is a P0113 which is likely because of pulling the intake tube to get enough room to work on the OPDA.
 
If you remove power from the battery and wait long enough it should reset the computer and also clear the CEL which is why you're in limp mode. YES, the CEL needs to be cleared either by keeping the battery unplugged for a sufficient amount of time or clearing the code with a scanner (which you don't have yet).
 
If you don't have a code, it shouldn't be in limp mode.

Did you have a cam sensor code before? Did the old OPDA have wear? There's nothing to suggest you needed a new OPDA so far.

You don't need the tool to relearn the cam/crank either.
 
JKP said:
If you don't have a code, it shouldn't be in limp mode.

Did you have a cam sensor code before? Did the old OPDA have wear? There's nothing to suggest you needed a new OPDA so far.

You don't need the tool to relearn the cam/crank either.
Click to expand...

The old OPDA looked fine, shaft seems tight, slight play. Gear looked about the same as the new one. It had the same Dorman 689-201 number etched in it.

I was making a trip to the city all interstate so I ran it down to about an 1/8 tank, put 2 cans of Berryman B12 in it and filled it up with premium. Hoping to clean up the injectors and the slightly rough idle. Ran about 20 miles when it started acting up and flashing the CEL. We were close to the destination so limped another 20 miles while it ran worse and worse. Got towed home.

Googled for a couple hrs and thought it all sounded like the OPDA so I ordered one and swapped it out this evening before I learned the 3 on/off key trick to pull the codes. I was hoping to get this fixed fast because Mon night my Dodge rode home on the tow truck with what I think is a bad TIPM. Daddy has to get to work somehow.

I just ran out and pulled the battery cables and will let it sit overnight and hope for the best in the morning.
 
A flashing CEL usually means it's misfiring badly enough to damage the catalytic converters.

When it throws the cam sensor codes, it turns on the CEL, but it doesn't flash. It will put you in limp mode.

When you hook the battery back up in the morning, take if for a drive and see if it throws any codes. Some of them require the engine to be up to temp or above a certain RPM.

Post back what you find.
 
Ok, fired up this morning with no CEL. Let it idle for a few, then drove 7 miles to work on side roads. Made it here with no CEL. However it still runs like crap, no power, I can run it up to 3500rpm IF i keep my foot out of it. Accelerate too briskly and it falls on its face. Engine/Exhaust seems MUCH loader. Would a cracked manifold set a code? O2 sensor should trigger for a bad CAT?
 
Does it feel like it hits a rev limiter when you floor it or does it just cut off?

A weak coil will just shut down when under load. However, there are 3 coils in the rail, so unlikely they are all weak. 2 cyls per coil.

A weak fuel pump feels like bumping off the rev limiter
 
have you checked the spark plugs ? my brother bought a tj and it ran like crap same thing skipping, and CEL before he even got it home ! pulled the ORIGINAL plugs out and the electrodes were almost gone, no wonder it was running like shit with the plug gap over .100 instead of the .035 i believe it is !
 
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I believe OEM gap is .040 for plugs. I was amazed what set of plugs did to both of our TJ's when 72K and 56K miles. Ran sooooo much smoother with new plugs. $30 in plugs and maybe 30 min to swap out....good investment of time and $$
 
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JKP said:
Does it feel like it hits a rev limiter when you floor it or does it just cut off?

A weak coil will just shut down when under load. However, there are 3 coils in the rail, so unlikely they are all weak. 2 cyls per coil.

A weak fuel pump feels like bumping off the rev limiter
Click to expand...

It feels like a rev limiter. It stumbles if you push it too hard but does not die. I wonder if the Berryman B12 clogged the fuel filter or an injector seal?
 
I'd check the fuel pressure. They will loan you a gauge at most parts stores. Unfortunately there is not a port on the rail, you will have to use the adapter in the kit between the fuel line and rail.
 
OK, ran to wrok 7 miles like crap. Came home and flashing CEL but no code. Drove it to town this morning and a CEL. P0300 code for misfire.

Parts Store and acquired a coil pack, some plugs, and the Fuel Pressure Tester Kit. Will try and get to it Sun. Thanks for the help!!
 
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Weather forecast tomorrow is 102º so I swapped parts tonight. New Plugs and Coil Rail. Cleared codes with my new Autel MK808S Scanner. Fired it up an let it idle. Dialed in the Cam/Crank Offset to about 0.8º and did a Cam/Crank Relearn. Still setting a P0300 Multiple Cylinder Misfire.

Old plugs were NGK and looked bad. Gaps were burned pretty wide. Front #1 was brown and looked the best of the 6, 2&3 were brown and the back 3 were black but not wet.

New plugs are Champion Platinums and the Coils Rail is O'Reillys house brand as that was all I could find in stock today.

I can't see how I'd not have enough fuel pressure with the plugs being so dark? But I will get the tester setup tomorrow.

Jeep Plugs.jpg
 
Are the plugs double platinum? Singles don't play well with the coil rail.

Have you changed the crank sensor? The PCM fires the coils based on it.

The upper O2s control the mixture once it's up to temp. If you unplug them it will force the PCM to preprogrammed values.

You can check the MAP sensor with the scanner. Take a reading with the engine off and compare to the absolute pressure at your location. There are apps that you can use on your phone to read the absolute pressure.
 
JKP said:
Are the plugs double platinum? Singles don't play well with the coil rail.

Have you changed the crank sensor? The PCM fires the coils based on it.

The upper O2s control the mixture once it's up to temp. If you unplug them it will force the PCM to preprogrammed values.

You can check the MAP sensor with the scanner. Take a reading with the engine off and compare to the absolute pressure at your location. There are apps that you can use on your phone to read the absolute pressure.
Click to expand...

P0300 Code was set while idling before it was up to temp. Have not done O2s.
Have not changed the crank sensor. Will see if I can source one. I will dig around in the Autel and see if I can read the signal.
Champion Double Platinum 7034.

What would make it run so rich? This came on pretty quick after dosing with the Berryman B12 and getting fuel. Coincidence? Injectors issue?
 

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