O.K. I have replaced and rebuilt numerous 3.0 's and this a first one for me. I have a 92 4rnr that smoked ALOT on start up. Ran great otherwise. No. 2 cyl. was bad. So, I had another 3.0 that needed a crank. Replaced the crank and installed the motor, using all of the access. off of the original motor. Now that it is together, I cannot get it to run. It tries to start, but no luck in running. I have recheck all timing and dist. marks. It is getting fuel and spark. When I try to start it w/ the intake off, it backfires thru the throttle body. What am I forgetting? I did not unhook any vacuum lines, just unbolted the intake and layed it out of the. I used the orig. injectors from the running motor as well.

 

Have you tried starting it with the intake on? You need the afm all hooked up for it to run.

 

I hooked the AFM up and it still does not start. It tries to start, but no luck. I am getting a cyl. compression tester today and checking the cyl's. Could a stuck valve cause it to not start? The "new" motor was sitting for awhile, before I rebuilt the bottom end.

 

Backfiring out of the TB sounds like something is not lined up. Line it all up at TDC, (confirm that again...), then make sure your distributor rotor is pointing at 11:00.

 

I have done that three or more times now. I can move the dist. while cranking the motor, it tries to start, but doesn't.

 

sounds like the dist. is out 180 or your plug wires are out of order.

 

checked and re-check. Even replaced wires and dist. to no avail. W/ the AFM hooked up, I do not hear the backfire anymore. Only when I have the intake boot removed, do I hear the backfire.

I had to replace the knock sensor wire, as the orig,. one was broke. I had to change the plug end, if I did not attach it correctly, can that cause my problem???

 

YES.


Run the compression test, that will tell you probably.

 

I unplugged the knock sensor, no change in starting issue. I am getting the comp. tester tonight and going from there...

 

C'mon people, put your thinking hats on, what am I missing? I have re-checked timing AGAIN, using the lower timng gear instead of the mark on the pulley...In time. What else???

 

I had the same problem recently with a new long block. Distributor was 180* out.

 

timings off, mine did the same thing when it was 180 out. have u checked the timing belt to make sure it didnt jump a tooth or something too, cause if it did it can cause that too.

 

Computer went bad?

I have a 3vze, will not start. I too am missing something.

A loose wire connector? IH1? CPU connected? Distributor broken?

 

NOT TIMING! But, after checking cyl. compression. No compression in #2. Valve cover off, intake valve stuck open. Great, now I get to pull the friggin head....Geez. Looks like I found the mystery problem....

 

but if im not mistaken one open valve would not cause it not to run, just be poor running..

 

I will find out, I am replacing the head today/tomorrow when I have time. That is the ONLY issue I found, so far.

 

did u also check that u have good grounds, one on driver side and one on firewall connected to intake manifold? one of mine burned up one time and i couldnt get it to start but did spudder a couple times too.

 

All grounds are good.

 

O.K., after cleaning valves and such, I have the 3.0 running ....finally.... Now, I have CEL codes 24 and 53. I know the 53 (knock sensor), but what about the CEL code 24??? I can't imagine the AFM is bad, as it worked before(i.e. no codes) I put the "new" motor in...

 

FYI
Code 24-bad AFM
Code 52-Replaced Knock sensor and wire

Runs now, but no power. Poor compression, approx 125psi across the cylinders...