Swapped in New 4.0 and now it wont start? Help!!

GREATWHITEJEEP

New member
Ok long storry short? Bought my 01 from a shady used car lot with a bad cylinder head,. The Problem was masked with a few over the counter remidies .The jeep ran graet for about three months until it stated overheating . Looking deeper I noticed that the car lot had removeed the thermoastatit and the radiator and motor was loaded with Stop leak . I got screwed but I am tryying to make some lemonade ot of some bad lemons.

Bought an 04 motor with 36k from a local Jeep dismantler. When I had the motor out to compare, we realized that the Grand Cheorokee block is totally different and would not except the accesoors from my 01 XJ . So we exchanged the 04 motor for a correct used 01 motor.

After spending all weekend installing the motor ,it will not start. The old motor started fine and ran . After about 5-10 miniutes it would sattrt puking water into the cylinder head . The new engine turns over about 5-6 times and than sputters without starting. If this were not computer controlled I would be looking at the timing . That said I think it may be the Crank Positioning Sensor . I should have removed it from the bell housing before the engine swap. Could bumping it during the install or removal have killed it?? I pulled it out to inspect and it does look to have made contact with the Flywheel ring.

I have one ordered from Autozone ,but if this does not cure the problem ,I am at a loss. Any Ideas???

BTW While the Jeep was motorless we went ahead and installed a 4.5" lift that I scorred from Pick-N-Pull ,Half price . It is not the most expensive kit out there but for $200 bucks I got everything including Shocks .
 
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BIGSLVRXJ

New member
GREATWHITEJEEP said:
Ok long storry short? Bought my 01 from a shady used car lot with a bad cylinder head,. The Problem was masked with a few over the counter remidies .The jeep ran graet for about three months until it stated overheating . Looking deeper I noticed that the car lot had removeed the thermoastatit and the radiator and motor was loaded with Stop leak . I got screwed but I am tryying to make some lemonade ot of some bad lemons.

Bought an 04 motor with 36k from a local Jeep dismantler. When I had the motor out to compare, we realized that the Grand Cheorokee block is totally different and would not except the accesoors from my 01 XJ . So we exchanged the 04 motor for a correct used 01 motor.

After spending all weekend installing the motor ,it will not start. The old motor started fine and ran . After about 5-10 miniutes it would sattrt puking water into the cylinder head . The new engine turns over about 5-6 times and than sputters without starting. If this were not computer controlled I would be looking at the timing . That said I think it may be the Crank Positioning Sensor . I should have removed it from the bell housing before the engine swap. Could bumping it during the install or removal have killed it?? I pulled it out to inspect and it does look to have made contact with the Flywheel ring.

I have one ordered from Autozone ,but if this does not cure the problem ,I am at a loss. Any Ideas???

BTW While the Jeep was motorless we went ahead and installed a 4.5" lift that I scorred from Pick-N-Pull ,Half price . It is not the most expensive kit out there but for $200 bucks I got everything including Shocks .
First off I see you're pretty new here so, welcome to NAXJA. It sounds to me like your culprit is your crankshaft position sensor or CPS. It doesn't take much abuse to damage those little guys and if you left it on while removing the engine and bumped it with anything heavy, it could have damaged it to the point of not working. I was reseating a CPS on my 1990 one time and knocked the magneto off of it, it would still start but shot a 4" long blue flame out the tailpipe. The later CPSs though will cause a no start if you disrupted it I'm almost positive. Replace that and let us know what happens. And on the 4.5" lift, sounds like you got a smoking deal, nice score.
 

89xj

New member
what flexplate did you use? are the flexplates the same from both years? if you use the incorrect flexplate the cps wont pick up the signal at the correct time.
 

x99j

New member
89xj said:
what flexplate did you use? are the flexplates the same from both years? if you use the incorrect flexplate the cps wont pick up the signal at the correct time.
not only the right flex plate but doesn't the flex plate have to be indexed on the crank right, so the crank sensor can pick the signal up? if i remember their is no markings on the flex plate to tell were it goes on the crank (which holes in the crank line up with which holes in the flex plate).
 

89xj

New member
x99j said:
not only the right flex plate but doesn't the flex plate have to be indexed on the crank right, so the crank sensor can pick the signal up? if i remember their is no markings on the flex plate to tell were it goes on the crank (which holes in the crank line up with which holes in the flex plate).
i believe the holes are offset so there is only one way the flexpalte can go on.
 

GREATWHITEJEEP

New member
I checked with the Jeep dealer to see if there was a different part number on earlier jeeps- Flexplate and they said it is the same from 97-01 . Same thing on the CPS . I am farily confident that it is the CPS . I had the same issue on a 360 powered Dodge a few years ago. It would run but missed badily. We couldnt figure it out. The Crysler Dealer charged us $160 to swap out the CPS . I sure hope it is just the CPS .

When I am alowed to post pictures I will show some before and after photos of The 4.5 lift . I also took pictures of the XJ at the yard with the lift still installed. So if anyone recognizes that Jeep I am sure there is a tale to be told . I tried to sell the lift on Craigs list but no one wanted to pay me any $$$ . I am glad I kept it . I priced some budget 2"-3" and with new shocks they would have costed more than what I paid for this 4.5 lift complete. I was also surprised that I could get detailed installlation instructions online . Took us about 8 hours to install . With 31s I think it looks just right . 32s would fit no problems,but I would have to get wider rims .,I kinda like the way the 31s look on the 01 Sport Wheels . Rich



 

89xj

New member
i didnt notice that you swapped in an 01 engine, i thought you swapped in an 04 engine.
 

GREATWHITEJEEP

New member
The 04 engine block didnt accept the XJ accessorys. The altenator bracket lower mounting bosses are absent ,the motor mount bosses are cast differently, The waterpump mounting holes are off Ect... We exchanged the 04 for the correct 01 block . Rich
 

CharlesS

New member
You might consider rechecking all of the connectors that you removed while swapping the engines..
Does your XJ have the factory alarm system? I have heard that when the vehicle loses power such as yours has; there is something that needs to be reset to provide the ignition signal.
Have you checked the fuses that supply the ECM and sensors.
Verify the existence of 5V for the TPS, MAP sensor and CPS.

Hope this helps with you troubleshooting the problem.
 

GREATWHITEJEEP

New member
Replaced the CPS still wont start , I am Baffeled!! Help anyone in Sacramento? All I need is an anwser to the problem I am willing to do all the work.. Pizza Beer !!! I have a warehouse so if a guy needs a spot to work on their Jeep for a weekend I could be a good friend to have . HELP!!!

Rich
 

copper204

New member
Rich,

Did you just swap the block? Or did you also swap out the intake? I would take a real close look at the ground wires over on the passenger side, and make sure the all the connections are good on the motor. One simple ground can cause havoc. I have seen and found that usually a no start issue after swap is a ground issue. I live down in Sonora. But the week of 16, 17 and 18 I will be up in Sacramento taking class. I could probably come by and take a look at that time if you don't have it going yet. Hal


:wow:
 

Jarvis_Pants

New member
90PioSport99 said:
. I was reseating a CPS on my 1990 one time and knocked the magneto off of it, it would still start but shot a 4" long blue flame out the tailpipe.
Is this a mod anyone can do .... :roflmao:

i hope so!
 

GREATWHITEJEEP

New member
Hal, I hope to have it running by then, but if its not I would sure like to take you up on your that offer. At the laest you can come check out the Shop, shoot maybe we can hit a trial if you have time . My wifes brother has a 98 XJ with 5.5" RE lift and 33s and my nephew has a 98 on a stock suspension . We can go try to get the stock jeep stuck LOL . That is assuming that the no start Gremlins are excercised. I cant wait to test out the junk yard lift kit. I want to see how my $200 second hand lift compares to that $2000 plus Rubicon Express lift. I know the biger more expensive lift should outperform what I have, but as long as I dont take anything too extreme I should be OK. In any case it should be a lot of fun!!
 

GREATWHITEJEEP

New member
Took it in to the Dealer and $300 later it is alive !! It was a combination of fuel fouling and the camshaft position sensor was out . So they reset it at TDC and reset the computer with a Scan Tool. So All I need to do is fix the Shock mounts in the back and the downpipe studs and I am ready to rock !!!
 
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