akecj7

This is my first post and I am looking for some help, if this is not the right place for this please feel free to move it. Last year I put a junk yard Gen III 5.3L out of a suburban into my CJ7. I did the harness myself and had the pcm tuned by Wyan @ 150tunes.com. At first the motor seemed to be running fine then it started smoking at start up. I connected my scan tool and the long term fuel trims were way off bank 1 was reading 25.0 and bank 2 was -15.?. I posted on Pirate to my findings and the following is what I was suggested to check and the out comes.

Clean injectors by soaking in seafoam - When I was pulling the injectors out I broke on of the ears that retains the injector in the rail so I put all new injectors in.

When I put in the new injectors the motor would not start at all. I started trouble shooting sensors, spark fuel, ect. All sensors were good, injectors were pulsing, and I had spark and still would not start, it would crank for days but not fire. I decided to check the amount of spark at the plug. The plugs were hardly firing so I put new plugs in. When I tried to start it, the motor turned over a couple of times and fired. The motor ran good and both fuel trims where the same still off but the same. When I started the motor yesterday the fuel trims were back to where I started with bank 1 @ 25.0 and bank 2 @-15.?. When I measured the temp @ the manifolds while the motor was running and they were about 150 on bank 1 and about 200-250 on bank 2. There was only one that got as hot as 300 but it was only for a min.

Other things that I have tested was compression (all @ about 150 with the exception of #8 and it was @ about 135), pressure @ the rail is 60psi.

Any help and or suggestions would be greatly appreciated.

76larkman

list this in fuel section you get answer to it.

MuhThugga

What color was the smoke?

akecj7

white, it did not smoke the first time I started it after I put it in my CJ.

MuhThugga

It sounds like you are burning coolant. I would look to see if you have the Castech heads. You may have a cracked head.

Mercier

iTrader: (15)

^^^ Good point above. Look at the 3-digit number stamped on the outside end of the head. If 862, no Castech. If 706, might be Castech. Those were known for cracking. If you have 706, google "Castech crack head" and you'll find a load of info. Hopefully you have 862s and can at least scratch mfg defect off the list. You could still have a head gasket or similar issue though.

White smoke is almost always water/coolant in the exhaust though so something you should follow down. Curious where your steam vent piping runs to? I've seen it (mistakenly) looped into the PCV and basically introducing coolant there. Not good.

Johnathan Plummer

I have a 5.3 new alt new battery cables cleaned starter test cranks butt won't start and battery doesn't maintain charge

akecj7

Thanks for all of responses. I thought about coolant but oil looked normal and the smoke did not smell like coolant or at least what I have seen in the past. I will check the casting numbers when I get home. I looked at them once before and cant remember what it was. Also the steam ports are all factory and the one that comes out of the throttle body is going into the radiator.

akecj7

So I do have do have the 862 heads. Now to check the head gaskets. Is the best way to pressure the coolant system and see if the pressure drops?

MuhThugga

You can pressure test.

There is also a test you can do to see if combustion gasses are getting in the coolant. Just search for a coolant combustion gas tester. They are inexpensive.

akecj7

okay kinda of an update. I pressure tested the coolant system to about 26 psi and it held that pressure for about 15 mins until I removed the tool. I read online (how valid a test it is i'm not sure), remove the radiator cap and crank the motor and see if coolant shoots out of the radiator. Did this and nothing came out. The only test that I have not done that is suggested is to test if there are combustion gases in the coolant.

I let the motor run for awhile this weekend and the smoke (when cold) is probably more gray than white. The smoke has never smelled "sweet" just more dirty. When I rev the motor it will smoke darker smoke than at a cold start up. I am going to check to make sure that I have don,t have an intake leak someplace next as soon as I have time. Also what is the best way to clean the MAF sensor? Thanks again for all of the ideas.

Mercier

iTrader: (15)

On the MAF, remove it from the vehicle and spray liberally inside(especially the wires and such inside the unit; not the electrical connectors, but the sensor wires in the airflow path) with either specific MAF cleaner or "quick drying electronics cleaner.". Both available at most parts stores. Do NOT use carb cleaner or throttle body cleaner as it can leave a residue..brake cleaner wont leave a residue but might not leave any sensor wires behind either so stay away from that too.

Basically MAF electronics are sensitive so always use the right thing and always be very careful. Once done, shoot it again just for ***** and then let dry for about 5 minutes, reinstall, and enjoy. If you think your fuel trims were WAY out of whack due to a very dirty sensor, then you will want to drain the computer by disconnecting the battery with the key on for an hour or so. It will run funny until it figures itself out but will adjust for the new(hopefully more accurate) readings from the newly cleaned MAF.

There is no scrubbing or physical interaction in the cleaning BTW. Just spray it real good. Then spray it again. Repeat until satisfied. If you so much as touch those little wires you will likely be shopping for a new MAF. I also put dielectric grease on all harness connections(electrical plugs) Ensures a good connection and seal and keeps moisture out. Can be real helpful in a Jeep, depending in what you do with said Jeep. I don't always drive myself nuts doing every connector at once unless I plan on submerging the thing..just always keep some handy and apply any time I have the occasion to disconnect something.

Good luck!

akecj7

Okay I am still having issues. Still no codes showing up what so ever. Engine runs but runs bad. Seems to have a miss and has a pretty rough idle. Here is everything that has been checked/replaced: New injectors, new plugs, new wires, new intake gaskets, checked head gaskets, and all sensors. I have also checked exhaust manifold temps at the head. The temps on bank 2 (passengers side) are high 200's or low 300's. The temps on bank 1 are all in the low 100's. I am about ready to call it quits on this motor and save for one from Pacific Fab or similar. Here are pictures (all taken with in a minute or so of each other, that I took from my scan tool this afternoon. If anybody has any suggestions I am open 100% to them. Could this be an ecm issue?

speer13

Have you gotten an answer yet? Not sure about this but looking at the data you are showing I would think you need more timing... 5 degrees advanced at 70kpa, I would think you need near 20 at that RPM... but I could be wrong

Bowtie316

iTrader: (1)

Has this swap ever ran right? If not, I would check to see if your bank 1 and bank 2 O2 sensor wires are swapped to the wrong bank. Having one go so lean and 1 go so rich would indicate that they are swapped.