Ok so I have a customer that brought in a 2000 s2000 and he wanted us to put it back to stock after he blew his other motor up. We removed everything from the car (turbo kit etc) and put in a stock wiring harness, stock motor and stock ecu. The problem im having is like nothing Ive ever seen before. When you go to crank the car over it sounds like the car is in time and then goes out of time and then back in time again. If you put your hand on the intake you can feel the motor sucking in air and the after a few cranks it starts blowing air out and then a few more cranks it starts sucking air back in. So I checked the timing and it is dead on. I checked the crank sensor and cams sensors and the are getting signal and look good on my scanner. I gave it a compression test and the first few cranks it does nothing and the it shots up to 200, this happens on all 4cyl . I am stumped and tiered and will come back to it in the morning. Please forgive my grammar but I am to tiered to care right now.

Thanks for any help or suggestions.

 

any cel? try to change out the ecu.

 

LEAKDOWN!

 

Ok here is another twist. I checked the timing again just be sure I wasn't sleep working. I checked it and its out so im like yes!!!. Well I set the timing and then after a few cranks it starts doing the same thing again. . So I check the timing again and its off. So I check the tensioner and its in good shape. So I put it back in time and this time around I turned it by hand. I turn it and the first time around its 180 out like its supposed to be and when I turn it back around again to line everything back up its one tooth off. Keep going and every 2 revolutions it keeps getting a tooth off . So I reset it again and the same thing keeps happening. So I got to my s2000 pop off the valve cover and mine is on the money every 2 revolutions like clock work. What could cause this?

 

What about the timing chain auto tensioner? Did you try a new part here?

 

if u do not retract the tensioner via a bolt and just push the tensioner in by hand or using the mounting bolts to pull it in tight, it will mess up the timing. I've had this happen to me. u must retract the tensioner then put a pin across the tensioner holder holes then set timing, then pull the pin out through the maintenance hole on the head, thus releasing the tensioner. don't ask me why this makes a difference, you would think it wouldn't matter, but it has something to do with the amount on tension it puts on the chain when your forcing it to retract... that is if your doing it this way. to make a holder pin, I cut a very thin allen key to make my own holder. all of this is also in the shop manual which should be followed cause this is important stuff for a motor, I don't care how many years of experience one would have.

 

Ok so I found the problem . I finally took everything apart and found a chunk of plastic stuck on the bottom gear behind the timing cover where the crank is. I do not know the history of this motor so I don't know how it got there. Im surprised it didn't throw the chain. It was enough to throw the timing off 1 tooth every revolution. I wish I would have taken a video so you guys could have heard what I heard. I have cars come in out of time all the time but I have never had one with a mind of its own going in and out of time like that. Well the problem is solved. Thanks for letting me vent.

 

good to know