RX8 cranks but won't fire

In reply to Pete. (l33t FS) :

Yes I waited on the white fog. I did overlook the oil. 

In reply to Slippery :

You haven't been forgotten. 
 

Im still concerned about step 1 in most diagnostics- go back to the last thing you did and double check. 
 

Since I don't know what she did, I'm still trying to figure out if there is anything stupid that could have happened with her removing and cleaning the throttle body. If she knocked a wire loose or or blew a fuse or something. 
 

If there is something we missed, then it won't start with a pull start either.  I'm willing to pull it, but I'd really like to know everything is in order before I try that. 

In reply to Pete. (l33t FS) :

Oil before installing spark plugs.... is that just standard motor oil?

In reply to SV reX :

I'll step in for Pete here and he can yell at me if he disagrees. 

Whatever is in the crankcase, or just any engine oil. I would prefer synthetic since it leaves less/no carbon buildup when it burns, but its such a small amount that anything to initially lubricate will work. 

In reply to Slippery :

Thanks

In reply to Slippery :

Anything oily. Motor oil, ATF, whatever you have at hand that has some viscosity to it.

I'm not against synthetics in rotaries, other than it seems like a waste of money.  If the oil is getting hot enough that a synthetic is preferred to non synthetic then the engine is extremely unhappy for other reasons, and the oil life is short enough that there are no long OCI benefits.

The no synthetics in rotaries stems from a certain oil making a LOT of deposits, and rather than call out "don't use manufacturer X" they simply said, don't use synthetics.  At the time the synthetics were Amsoil and Mobil 1.

In reply to Pete. (l33t FS) :

educate me please, because I'm running Mobile 1 Super 2000 (semi-synthetic) in my Mazda.  Please tell me the Amsoil was the one that created said deposits.

Pete. (l33t FS) said:

Anything oily. Motor oil, ATF, whatever you have at hand that has some viscosity to it.

The no synthetics in rotaries stems from a certain oil making a LOT of deposits, and rather than call out "don't use manufacturer X" they simply said, don't use synthetics.  At the time the synthetics were Amsoil and Mobil 1.

The one time I flooded my FD, I managed to solve it without taking the plugs out.  Disable fuel injection (I think I pulled a fuse), crank with throttle wide open, then I sprayed WD40 in a vacuum port.

As for oil, Idemitsu makes a bunch of synthetic rotary-specific ones.

https://mazdatrix.com/product/oil-10w-30-idemitsu-idemitsu-10w-30/

I'm with you, Paul - it would be an awfully large coincidence that she drove it, worked on parts (maf & tps at least),  reassembled and something else happened to break. 
 

Your summary:

"This week she put it in the garage to clean the TPS and the MAF sensor.  Yesterday it started fine (still unassembled) to move in the garage.  Today she got the whole thing back together (airbox, MAF, intake accordion air duct hose all removed and cleaned and reinstalled).  Also replaced a couple vacuum fittings and bad hoses.

Now the car cranks (strongly), but won't fire.  Didn't note any plugs still disconnected.  I can hear the fuel pump."

i would test the tps and the maf or at least swap out known good ones just to test   

In reply to jfryjfry :

I think I worded that poorly. She removed the throttle body to clean it (not the TPS). Of course in order to do that, she had to r&r the TPS.

You could use a BT-OBD device to check for sensible values from the TPS & MAF, although there would probably be an error code if that were the issue.

Hungary Bill (Forum Supporter) said:

In reply to Pete. (l33t FS) :

educate me please, because I'm running Mobile 1 Super 2000 (semi-synthetic) in my Mazda.  Please tell me the Amsoil was the one that created said deposits.

Given that Amsoil sponsored a major racing effort, probably Mobil 1.

I am assuming that you aren't using 40 year old oil.  The issues were at least that long ago.

SV reX said:

In reply to jfryjfry :

I think I worded that poorly. She removed the throttle body to clean it (not the TPS). Of course in order to do that, she had to r&r the TPS.

You don't, it's part of the throttle body.  As in, it's PART of the throttle body, it can't be removed without a lot of work.  It looks like the same drive by wire unit that a lot of Fords used.

jfryjfry said:

I'm with you, Paul - it would be an awfully large coincidence that she drove it, worked on parts (maf & tps at least),  reassembled and something else happened to break. 
 

Your summary:

"This week she put it in the garage to clean the TPS and the MAF sensor.  Yesterday it started fine (still unassembled) to move in the garage.  Today she got the whole thing back together (airbox, MAF, intake accordion air duct hose all removed and cleaned and reinstalled).  Also replaced a couple vacuum fittings and bad hoses.

Now the car cranks (strongly), but won't fire.  Didn't note any plugs still disconnected.  I can hear the fuel pump."

i would test the tps and the maf or at least swap out known good ones just to test   

 

Early rx8s would flood and not be able to be restarted fir HOURS if you drove it less than 10 mins.

That's My guess with this.

Sometimes they needed pull started if the compression wasn't top notch.

Pete. (l33t FS) said:

SV reX said:

In reply to jfryjfry :

I think I worded that poorly. She removed the throttle body to clean it (not the TPS). Of course in order to do that, she had to r&r the TPS.

You don't, it's part of the throttle body.  As in, it's PART of the throttle body, it can't be removed without a lot of work.  It looks like the same drive by wire unit that a lot of Fords used.

I meant remove from the car, not remove from the throttle body. You remove it when you pull the throttle body (which means you disconnect the wiring, and therefore a potential problem)

Pull start was the answer. Some oil in the cylinders and a 20 mph tug in 2nd gear and it started very easily. 
 

Bravo to the GRM collective!  Thank you very much!