Please help me or I will die!

[Sizzler]

Okay, that might be an exaggeration, but I feel like I'm going to die. I just got finished putting my engine back together after finding a cracked head and it's still blowing white smoke! Compression test every cyl at 120. It struggles to stay at idle and dies if I don't give it gas constantly. I did every step by the book, gasket definately right side up, torqued all bolts to spec.

Is it possible that the coolant from before needs to burn off? I let it run for 5 minutes and it was still blowing white smoke. Please help! Please tell me it's not the block! I just spent 500$ and every night after work this week working on this darned thing! AH!!!!!

 

[scottmcneal]

Can you park it on a steep hill to see if it drains any out? How bad was your leak?

 

[Sizzler]

i don't understand the hill idea. the leak was not too bad. there was a crack in the head at cyl 3 so i replaced the head with a rebuilt one. i guess it was bad enough to cause a lot of white smoke. and besides the white smoke there is no indication that there is coolant in the cylinders now. i really don't understand. i spent so much time on this.

 

[Frank Z]

Dumb question...Did you change your oil?

 

[scottmcneal]

The muffler an cat can have some in them, Parked on a hill could let it drain faster with the motor running... I could be wrong... Just let it run longer sitting in driveway i guess.... Watch your coolant level.. Crap, didn't think of that frank

 

[xjtrailrider]

Let it run longer, if there is a problem letting it run most likely won't cause any more damage than might already be done.

 

[Ecomike]

Check the oil first. You did drain and replace the oil right?

The O2 sensor will be toast as engine coolant exposure kills them, so it should be running very rich.

What year is it?

You could have something else going on like a stuck injector dumping lots of raw fuel into it.

What grade oil are you running?

At 120 psi compression, you might want to run a thicker oil!

I would be real carefull about running it too long. I would shut it down and check the oil every 5 minutes. Check the oil for gas as well as coolant. Also check that throttle body vacuum connection to the MAP sensor and make sure it is attahced and not loose.

Did you do any other work on it????

 

[KRAKER]

I would let it run. Sometimes at work I'll get smoke for up to an hour. If you get no CEL and no obvious bad noises. Let it run. 120 psi is awesome.

 

[Sizzler]

UPDATE: Based on the idea that it couldn't hurt it (though I'm sure i could) I let it run for a while, actually drove it around the block and the white smoke cleared!!!! But now it dies if I let off the gas at idle. It cycles every 5 seconds or so, where it runs great for 5 seconds, struggles for a couple seconds, runs great for 5 seconds, struggles hard, runs great, then dies. Any ideas? where is the map sensor?

BTW, i changed the oil and filter, air filter, trans fluid and radiator. its an 88, using 10w/30 oil.

 

[99xjclassic]

Check all your vaccum lines.

 

[Bored400]

x2 on the vacuum lines. Also, please listen to EcoMike on this stuff...o2 sensors can throw your whole rig outta whack. keep us updated on your progress.

 

[Ecomike]

Disconnect the O2 sensor at the wiring harness. That forces the computer to run the engine in open loop mode. If it runs normally, does not die, that proves the O2 sensor is damaged and is causing your problem.

The MAP sensor is on the firewall, up high just behind the engine head / valve cover. It has a small black vacuum tube that runs from the MAP to the lower side of the throttle body to a black rubber plug that has two nipples that insert into the side of throttle body. Any vac leak in that line throws off the MAP sensor reading of engine vacuum and makes the engine run like Sh*t. It has a tendency to pop loose from the throttle body and is easily knock loose when doing other service work under the hood.

 

[88XJSport]

I once had bad idle like you described. If I let off the gas it would die, then i could restart it and die, 5 second intervals....turns out I had low fuel pressure.

 

[Sizzler]

UPDATE 2:

So, I replaced the O2 sensor and now it purs like a kitten! Well, there is a slight lifter tick that wasn't there before, but it's good enough for now.

THANKS TO EVERYONE THAT HELPED ME OUT THROUGH THIS!!! Not that anyone really cares, but this xj has been a nightmare. I bought it 2 weeks ago for 1500 from an aquentance, and just listen to all the things that have gone wrong so far:

1. The day after i got it, the heater valve snapped in half spraying me with hot coolant.

2. I fixed that, filled and burped the system and then it overheated and cracked the head.

3. Steering was hard to control, figured out that it was never alligned after lift, so I had to do that.

4. After allignment, was driving it and heard a strange noise coming from the front wheels. Figured out that 4 of the front drivers side lug nuts were ready to fall off and the 5th was already gone! And that was just the first few days. The rest of the week was spent fixing the head, where I found that

5. valve cover bolts only hand tight. Then both manifolds were missing several bolts and the rest were only hand tight. Then, found all tranny bell housing bolts to block were loose and ready to fall out!!!

Put in new o2 sensor, head, radiator, heater hoses, filters, gaskets, tranny cooler. Hopefully that will keep it running for a while. By the way, grand cherokee overflow bottles fit very well with the renix.

 

[Darky]

I'd talk to this guy and see about getting some money back. You can get an XJ in great condition for that price! Otherwise, enjoy the thing and have fun now that its back in shape. They're good vehicles and very capable. Hopefully it'll last a good long while like many tend to do. I'm at 150k with no major work. My achilles heel has been the starter. I'm on like number 5, but I tend to dunk them in the water on a regular basis...

 

[Ecomike]

So how did you come up with the name Sizzler? :doh:. Sounds like you brought a hasta back to life! Nice work!

Glad to hear the O2 sensor fixed it. So many times these older fixer uppers have several problems all at once. Sounds like you were down to the last one for now anyway.

 

[Sizzler]

So how did you come up with the name Sizzler? :doh:

it's from the name "sizzle-chest" which is just a dumb name to call someone. I used to use that name on jeepforum when i had my first xj, but after buying this latest jeep, i found that jeepforum is really crappy now and so i changed the name slightly and joined this forum, which is much better than jeepforum ever was.