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Rebuilt motor isn't running right.

J

JeepManDan

NAXJA Forum User
Location
Roseburg, OR.
Hey guys, Long story short, I tried a little mud hole, sucked some water into my motor, blew it up, and just put a new engine in my cherokee and it's not anywhere near running right, and this has me stumped.

The "new" motor is a non-high output out of an 89 cherokee. I tore it down and went through it. I used the block, head, crank, and cam from the 89 and then the intake, exhaust, and all the electricals from my 92 cherokee.

Now i've checked the ignition timing, and cam timing. Sometimes it will start up and run, but it runs extremely rough. I'm leaning towards it being a sensor of some sort that went bad from being submerged under water when it blew up. The water level was just over the bumpers.

If anybody has a clue as to whats going on, i would greatly appreciate it! Thanks
 
yes, it does. Ocasionally it will fire and sometimes even run, just rough. I used the flywheel off of the High output. Where is the CPS? It wouldn't hurt to look it over.
 
CPS is on the backside of the motor, at the top of the bellhousing, drivers side. It can be a bitch to get too... i drop the trans about 6-8", then use a 3foot long socket extension... similar to pulling the motor.

AFAIK, the H.O. flywheel and cps must go together... the holes in the flywheel that the cps reads crankshaft position off of, is differant than renix, its possible that its close enough, but still off? Assuming of course you didnt swap to the H.O. cps...

As far as rough idle post engine swap trouble... i would check for leaks between the intake manifold and the head (should make the engine rev super high, and be super loud). I'd also check the cylinder specific stuff, ie make sure all 6 spark plugs are firing crisp blue sparks. Also assure that all the fuel injectors are firing, i disconnect the electrical connector on the fuel injectors, one at a time, with the engine running. You will either notice the motor switching to running on 1 less cylinder (should start shaking), or if nothing happens, that injector aint firing!
 
with two people, one holding the socket with a super long extension with a universal and a short extension at the end, and the other super skinny person (like me) guiding it to the bolts, you can do it in about 10 minutes
 
I am using the flywheel and CPS off of the high output. It's to my understanding that the flywheel can only mount 1 direction, correct?

Also, the engine does have decent spark and it's getting enough fuel to hydrolock the engine so i don't think it's a fueling issue lol

If i can get it running I'll check for leaks around the intake. It does sound louder than before but it'll only run at around the 1500 rpm range. If i try giving it gas it falls on its face, and it's not running good enough to idle.
 
Also, i just checked the trouble codes. It looked like a darn light show in there.

The codes I'm concerned about are;
23-Intake air temp or circuit
and
54-Distributor sync pickup.
 
I cant help you with the codes --new to H.O.--, but yeah, flywheel can only mount 1 way, and in 1 phase... if its not on perfectly, all 6 bolt holes wont line up, and it wont bolt on.

Have you checked for vacuum leaks? Particularly the line that goes to the MAP sensor at the firewall? what your describing is starting to sound like a map sensor thats not plugged in! electrically, or vacuum wise.
 
air intake shouldn't stop it from starting.. however the distributor sync code will. Make sure the engine is on TDC when you put the distributor in. http://www.angelfire.com/my/fan/dist_index.html If that doesn't fix it, it maybe a bad cam sensor, which is in the distributor.
 
Yup, I've checked and the vacum lines appear to be good.

I know the timing is dead nuts, so that leaves the cam sensor.. Is that going to be it? they're spendy!
 
The Cam sensor in the <00s has the holes to use the toothpick(be careful when removing the brittle plastic base w/ sensor). You want to use the hole that is beside the end of the upright metal(there are 2-3 holes in there, only one on the metal base). TDC at the end of the compression stroke, oil pump slot aligned per cruiser's link, dizzy locked with toothpick, drop in at the right spot and it will rotate and the rotor when you put it on will be just past the #1 terminal(you can mark the base before removing cap to verify). If it's bad enough that the pcm gives you the code and you're experiencing the symptoms of a misaligned CMP, then. . .
 
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I know it's not the timing. I've reset the timing probley 20 times and nothing I try seems to change it. I'm starting to lean towards the coil. i'm thinking it got some water damage after sitting in the water for a while.
 
JeepManDan said:
I know it's not the timing. I've reset the timing probley 20 times and nothing I try seems to change it. I'm starting to lean towards the coil. i'm thinking it got some water damage after sitting in the water for a while.
Click to expand...

Okay if your SURE about the engine timing how about the injector timing? Its easy to mix up the middle ones and two of them being crossed will cause a couple dead misses! Also check the injector pulse at each connector.

My 89 MJ is getting an intermittent miss now that I have traced to one injector connector. If I rotate the injector toward the fron of the Jeep it never misses, put it back to the middle and it is hit and miss. I think its time for a new connector. Check that as well.
 
xjtrailrider said:
Okay if your SURE about the engine timing how about the injector timing? Its easy to mix up the middle ones and two of them being crossed will cause a couple dead misses! Also check the injector pulse at each connector.
Click to expand...

The injector timing should be right, I made sure to label the connectors before i tore took them off.

Talyn said:
Have you checked any of the sensors?
Click to expand...

I haven't really, where should i start and how do i test them?


But on a side note, after tinkering with the timing, codes 23 and 54 no longer show up. Now i'm just dealing with:

12- Battery disconnected
and
41- Altenator relay switch.

Now i saw somewhere that code 12 means the battery or power to the ECM has been diconnected within the last 50 key cycles. The ECM should get power from the battery, and not the alternator, right? So now i figure going through 50 key cycles with battery connected should be my next step. If it still pulls up a code 12, then maybe i have a faulty ECM.

EDIT: It's still pulling up the code 12
 
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