I'm at the end of my rope with this car. I've searched and searched and read and read and tried to troubleshoot the car to the best of my personal abilities... and it's no game. I'm looking for anyone local with a bit of know-how who would be willing to come out and help me try and either figure out what the problem is so that I can fix it, or decide whether or not the motor itself is toast.

About the car:

'Sabine' is a 1988 RX-7. She's done 76,000 on the shell, 18x,xxx on the transmission (I converted it to a manual) and unknown mileage on the motor, which is not original to the car. When I was doing the manual swap, I found bits of pilot bearing in the back of the e-shaft.

I bought the car as a non-runner. It seemed to only be severely flooded from a bad battery... I remedied this with a new battery and after some de-flooding, she fired and ran. One thing I noted about the car early on is that it didn't make ANY power. It's really like stepping in sand when you lean into the throttle. As the revs build, say, past 4,000rpm it sounds and feels (High frequency vibration throughout the car) as if the motor will blow itself to pieces. I suspected it could've been the auto tranny + the torque converter just being a piece of ****... fine by me, I intended to convert the car to manual...which I did with no real issue other than the main ground.

Something else I noted early on is the amount of cranking it took before the engine would fire. Sure, it was probably flooding out a bit from old leaky injectors. I had them cleaned and 'rebuilt' through Witch Hunter. Turns out they didn't leak and were actually in very good shape prior to the cleaning.

The length of time it would take cranking the motor over before it would cough into life got longer and longer as I continued driving the car until finally it just wouldn't start one morning. I eventually (Through de-flooding, waiting, and trying again) got it to breathe life again. This made me suspect low compression.

So, I borrowed a compression tester from a friend...home made kinda jobby. Results were not very promising...75psi front, 65psi rear. This is not at all considered good. My intentions were to pull the motor and swap it with my other FC which I no longer own. That didn't happen.

Fast forward, I borrowed another compression tester...another home made but supposedly more accurate deal. Numbers are around 90 front, 80-something rear. Those are horrible numbers, but technically they're high enough to have a car that'll reliably start and run alright. I've installed a temporary fuel cut switch...and installed new spark plugs...and I also did a fuel pressure test (Several). Fuel pressure, spark...all good. The fuel pump cutoff doesn't have any affect whatsoever on my ability to get the car started while the engine is cold.

Though, if the engine has some temperature in it...it'll fire over after several seconds of cranking.

It runs smoothly, drives fine...but it makes no power. When the engine isn't warm enough, it'll refuse to start unless I really spend some time working at it.

I've checked and readjusted my timing multiple times. The CAS might be stabbed wrong by one tooth, but there's enough adjustment available to get the engine in time where it's supposed to be. If anything, putting it at the factory spec made the problem worse.


I'm prepared to use my tax refund to buy me another used motor that's known good, but assuming the compression tester is accurate, I can't give up on it just yet.

If anyone is interested in working something out, let me know.

Thanks.

 

My car ran like dookie until we found that the front cover was off, and the timing was jacked. Is it possible to install the S4 pulley wrong?

 

I'm not sure. The car runs smoothly once started. Did your car run smooth once you got it going?

 

I had a second gen (s4) that seemed low on power and hard to start once. Turned out the front pulley was from the wrong year or mounted wrong.

I would start with that. Clock the flywheel to a known rotation and check the pulley.

-billy

 

Billy, after some searching I found that there is only way that the pulley can be mounted because the four holes are offset... 1st gens apparently have no orientation and can go on any which way be it wrong or right. So now I'm a bit more confused

I also found that you can use an S4 or S5 pulley without issue because they're identical.

I wonder if I should just borrow Ray's timing gun again and re-stab the CAS to see if it has any effect? From what I've been told it can't be off by more than a single tooth and shouldn't have any effect since I can still time the car correctly. Do you think it's worth a try or is it a waste of time?



BTW this is how I feel about the car right now...

 

make sure you have the injectors wired up right meaning front and rear rotors the harness will let you put them in the wrong spot

 

Oh snap, sorry guys...figured this one out. Turned out to be the starting circuit wasn't working properly and the ECU wasn't seeing that the car was trying to be started, as a result, it defaulted to using the readings from the mass airflow for guidance which isn't adequate.

 

good find, if you ever need help again send me a pm.