RescueDuck33 Posted June 19, 2015 Share Posted June 19, 2015 Having trouble with my 2001 XJ. Won't rev over 3000! Also showing injector 3,4 misfire. Any help would great two rides down isn't good. Replaced spark plugs,TPS,Cam Position sensor, and pull top injector plug on 3 no change on idle rest caused rougher idle. Link to comment Share on other sites More sharing options...
Eagle Posted June 19, 2015 Share Posted June 19, 2015 Same thing happened with my wife's 2000 XJ a few years ago. What code did you get -- by number? Injectors don't "fire," they inject, so I'm not sure from your description if you got an injector code or an ignition code. In my case, the code was for ignition. After replacing all the spark plugs (since the vehicle had 90,000+ miles on the original plugs at the time, the cure finally turned out to be a new coil rail. Link to comment Share on other sites More sharing options...
RescueDuck33 Posted June 20, 2015 Author Share Posted June 20, 2015 I have replaced coil pack twice in the last year. First one I bought from autozone second I bought from jeep. On the codes have to scan it again to get the codes don't remember the exact numbers. Link to comment Share on other sites More sharing options...
Eagle Posted June 20, 2015 Share Posted June 20, 2015 I have replaced coil pack twice in the last year. First one I bought from autozone second I bought from jeep. On the codes have to scan it again to get the codes don't remember the exact numbers. Interesting. I went through two with my wife's XJ, as well. But I bought the first from the dealer, and it lasted exactly one year. I bought the second from Auto Zone because it has a lifetime warranty. So far, so good. If the code you're getting is injector specific, it seems like you've replaced everything except that part that's probably causing the problem. Why not try another injector? Link to comment Share on other sites More sharing options...
RescueDuck33 Posted June 20, 2015 Author Share Posted June 20, 2015 I have a parts 2000 XJ and took the whole fuel rail off it and tried it still rev limit type problem at 3000 Link to comment Share on other sites More sharing options...
Eagle Posted June 20, 2015 Share Posted June 20, 2015 Possibly a bent valve, or a collapsed lifter? Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted June 20, 2015 Share Posted June 20, 2015 What's the compression in all the cylinders ? Are you losing any antifreeze , or is it mixing with the oil ? Link to comment Share on other sites More sharing options...
RescueDuck33 Posted June 20, 2015 Author Share Posted June 20, 2015 I am losing coolant. Haven't done a compression test yet. Link to comment Share on other sites More sharing options...
tugalo Posted June 20, 2015 Share Posted June 20, 2015 Since you are losing coolant, you may have a cracked head. I believe it was in 2000 that XJ's went to the 0331 head which had a new metal composition that was prone to cracking between the #3 and #4 cylinders. Look along the drivers side of the head where it attaches to the block and you will see the casting number. If it is 0331, that could give you a clue. Go over to the XJ forum naxja.com and you should find plenty of info. Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted June 20, 2015 Share Posted June 20, 2015 Since you are losing coolant, you may have a cracked head. I believe it was in 2000 that XJ's went to the 0331 head which had a new metal composition that was prone to cracking between the #3 and #4 cylinders. Look along the drivers side of the head where it attaches to the block and you will see the casting number. If it is 0331, that could give you a clue. Go over to the XJ forum naxja.com and you should find plenty of info. ^^ this . See if the head is an improved TUPY head , which is stamped on the top of the head beneath the valve cover by the 3rd cylinder . Compression and leak down test would be what I did next . Link to comment Share on other sites More sharing options...
RescueDuck33 Posted June 20, 2015 Author Share Posted June 20, 2015 Will do that and get back Link to comment Share on other sites More sharing options...
shelbyluvv Posted June 20, 2015 Share Posted June 20, 2015 I'm thinking a cracked 0331 head as well. Link to comment Share on other sites More sharing options...
Rockfrog Posted June 20, 2015 Share Posted June 20, 2015 Yup, pop out oil cap and look down through, that's right where it cracks. Dealt with it on my XJ back in '05. You can replace the stock coil rail with the 6 pack coil from a Viper, and a set of plug wires. Just need to extend the stock wiring to where you mount it. Also helps make diagnosing some issues easier. Link to comment Share on other sites More sharing options...
RescueDuck33 Posted June 20, 2015 Author Share Posted June 20, 2015 PO303 Cylinder 3 Misfire Detected I can't see any name or number through oil cap hole. Getting ready to run compression test. Link to comment Share on other sites More sharing options...
RescueDuck33 Posted June 20, 2015 Author Share Posted June 20, 2015 Cylinder 1 115psi Cylinder 2 120psi Cylinder 3 0psi Cylinder 4 0psi Cylinder 5 100psi Cylinder 6 120psi Link to comment Share on other sites More sharing options...
RescueDuck33 Posted June 20, 2015 Author Share Posted June 20, 2015 Block last 0449 Link to comment Share on other sites More sharing options...
shelbyluvv Posted June 20, 2015 Share Posted June 20, 2015 Cracked head. Link to comment Share on other sites More sharing options...
RescueDuck33 Posted June 20, 2015 Author Share Posted June 20, 2015 So "Cracked Head" is that what's going on. Link to comment Share on other sites More sharing options...
shelbyluvv Posted June 21, 2015 Share Posted June 21, 2015 More than likely. You'll have to pull it to see if it cracked or a gasket let go. Unless you can see the crack through the oil fill. Link to comment Share on other sites More sharing options...
Rockfrog Posted June 21, 2015 Share Posted June 21, 2015 That's exactly where they Crack, when mine went I looked in the fill hole and there was a 'nice' green line, there is no number to be seen in the fill hole. The casting number is on the outside of the valve cover. On the head, not the block. The only head used in 2000/01 was the 0331. The TUPY didn't show up until 2002. Link to comment Share on other sites More sharing options...
RescueDuck33 Posted June 21, 2015 Author Share Posted June 21, 2015 Heads off thus far blown head gasket In between 3-4 cylinders Link to comment Share on other sites More sharing options...
RescueDuck33 Posted June 22, 2015 Author Share Posted June 22, 2015 Ok question if the head isn't cracked would you still put it back or upgraded to a better head while you have it off. Link to comment Share on other sites More sharing options...
Akula69 Posted June 22, 2015 Share Posted June 22, 2015 If the head is not cracked (I'd confirm with magnafluxing) you can re-install after getting it decked. I would certainly take the time to check the valve stem seals and valves...pay particular attention to the seats for the exhaust valves and have the seats ground (and install new valves) if necessary.'TUPY' stamped heads are a little difficult to find at a reasonable price. Best I can tell from the NAXA forum, the 'TUPY' head is named that because Chryco contracted them from a company with that name in Brazil. They supposedly have a higher brass content to make them less likely to crack. You could also consider going backwards to the 0630 head which is not prone to cracking but would require changing the intake and exhaust manifolds. Good read here: http://www.greatlakes4x4.com/showthread.php?t=661 Good luck! Link to comment Share on other sites More sharing options...
Rockfrog Posted June 22, 2015 Share Posted June 22, 2015 The intake will fit fine, the issue is the exhaust manifold from the 2000/01 will not seal to the earlier heads due to Port mismatch and location difference. You need to swap to the later manifold and down pipe to use the earlier heads. The 91-95 7120 casting is the best choice for a head with the 0630 being essentially the same minus the temp sender port at the back of the head (the 7120 flows better than the 0630 as well but since it's going on an outdated tractor motor it isn't an issue). The TUPY head was intro'd in 02 to fix an issue ... "That was not an issue" as far a Chryco was concerned. There is actually more material between the 3/4 cylinder to lessen the chance of cracking due to a thinness in the casting at that point after the 0331 redesign. My 2000 XJ has been running a 93 7120 head since 2005 when the original head cracked at normal operating temperatures. Currently the motor has 243K kms and the head cracked at 141K. The only parts I changed were the head, valve cover (because I liked it better) and exhaust manifold with down pipe to the trans crossover. You will aslo need to to reshape the driver side motor mount shield (one straight cut, fold over and rivet together is all pretty self explanatory when you see it). If you use the stock 00 valve cover with the earlier head you need the earlier valve cover gasket to match it. The 0331 valve cover gasket is specific to that head. You will also need to make some simple brackets to hang off the valve cover bolts to hold the coils rail in place (I made mine with a hand drill and a hacksaw out of home Depot aluminum). Or, you can swap to a Viper coil (the 6point coil) and add a set of plug wires, just need to extend the stock coil plug wires to wherever you mount the coil pack (the connector and pinnout are the same). Link to comment Share on other sites More sharing options...
RescueDuck33 Posted June 23, 2015 Author Share Posted June 23, 2015 Ok would you order a Clearwater Head,Edelbrock, or a 505 Performance stage 1 4.0 Head pros and cons this will be going on a 2000 XJ 4.0 Link to comment Share on other sites More sharing options...
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