jmann

Do the sensor first. Like I said before if it ain't even farting it's electrical not mechanical, either that or no gas, because if it had gas and spark there would be something trying to fire.

Stealth97

iTrader: (5)

A 97 will happily run (but with a CEL) without a crank sensor, so remove that from being an issue.

jmann

That doesn't seem logical but if you say it well then I guess it is so, I know a 99 won't. It still is an electrical or no gas problem.

Joe Perez

iTrader: (8)

In the '95.5-'97 cars, primary fuel and ignition timing is based on the dual-output CAS plugged into the back of the head, just as in the earlier cars. The crank sensor in these cars is used only to provide a high-accuracy reference for misfire detection as required by OBD-II, by precisely measuring crank position over time during individual engine cycles and looking for crank accel vs. decel after an expected ignition event. The CAS is unsuitable for this purpose owing to an insufficient number of pulses (only one per cycle) and the jitter introduced by cambelt flex.

The crank sensor didn't become the primary timing reference until the CAS was removed in the '99 model year.

As a point of curiosity, the '95.5-'97 engines use a different crank sensor, and a different crankwheel, than the NBs. On the earlier engines, a raw VR sensor is used which outputs a differential AC sinewave signal, and the crankwheel teeth have sharp leading edges but ramped trailing edges. (Or the other way around, can't remember.)

The NB crankwheel has square teeth, and the sensor, while internally VR, contains signal-conditioning electronics which produce a square wave via an open-collector output.

stefanst

iTrader: (1)

No spark means no sync, or something else, like ignition interlock, is interfering. Check the CAM sensor!
Don't know about NAs, but US NBs won't start without the clutch depressed. And yes, I know somebody who had his (new to him) Miata towed because he didn't know that. No, that person is not a friend, merely an acquaintance.

Are you running stock ECU?

Joe Perez

iTrader: (8)

This applied to NAs as well. On any Miata, however, the clutch interlock interrupts only the starter itself, and has no effect on any other circuits (ECU, injectors, ignition, etc.)

A clear reading of the first post in this thread indicates that the starter is operating normally. This problem is not related to the clutch interlock switch.

stefanst

iTrader: (1)

Indeed. I should have known. So my new posting rules are: Don't post before the third cup of coffee. Don't post drunk. The window is getting smaller.

deadohiosky1984

So if I am understanding correctly you are saying that the car would run even with the crank sensor out but the car will NOT run with the CAS sensor out?

I have tried to unplug the crank sensor and turn over the motor to see if there is any CEL thrown but there is nothing. I have cranked it with the crank sensor connected and disconnected and it never gives me a CEL.

The CAS looks to be clocked well in the pics I posted of TDC but I could be wrong.

mmmjesse

if you have no spark , have you checked that the coil packs are getting 12v and ground to them? That should be where you start and not straight to sensors. It could be something as simple as a loose ground or blown fuse. if you do have good voltage and ground, then move on to sensors.

Joe Perez

iTrader: (8)

Sorry for the late response.

Yes, that is correct. A '95.5 - '97 car will run normally (but throw a CEL) with the crankshaft sensor disconnected, and it will not run at all with the CAS (back of the intake cam) disconnected.


I think perhaps we should back up a bit here and ask a simpler question, given the nature of what you're describing. Does the CEL illuminate and stay on when you turn the key to "Run" without attempting to start the engine?

deadohiosky1984

I finally got around to doing the timing on the car! I have some pics of the front timing cover parts off to shot the timing marks on the cams and the crank.

Before any work began on the car I checked the CEL when the key was turned to the ON position, as Joe Perez recommended I do. There is a picture with the results. Once that was confirmed I removed the front timing cover parts and harmonic balancer to be sure that the cams and crank were properly timed.

After setting the timing I went through and made sure that all sensors and plugs were connected before attempting to start the car. Once I turned the motor over I still got no sputter nor misfire, only a cranking of the motor.

Here are some pics to show the timing being properly set:


















Anyone have any ideas as to what the issue could be now?

Maybe a recommendation to a shop that deals with electrical gremlins in the south Orange County California area (I am near 949 Racing, as a point of reference)?

jmann

The exhaust looks to be 1 tooth off clock wise, but it could be the camera angle also. Even if that was the case it would start and run fine. You have never said if you rechecked to see if you had spark. If no spark the above doesn't matter. Have you also checked to make sure your getting fuel????

Stealth97

iTrader: (5)

Exhaust cam looks off a tooth to me. Timing belt also looks WAY too loose. I'll bet it slipped.

Jmann beat me to it.

before I ripped the timing belt off I'd see if the injectors are firing and if plugs are lighting up, if neither then CAS sensor or wiring to it.

gooflophaze

20 teeth between the cam marks - it should be 19. The positions are right but there is too much slack between the exhaust and crank.

When you slip the belt on, put the crank mark at 11:30 position, then slip the belt on the exhaust (I use clamps to hold it) and bring the crank to 12:00 to remove the slack. At that point, the exhaust should be at 12:00 and then you focus on getting the intake at 19 teeth between marks with a wrench. To make it easy on myself I cut 19 teeth out of the old timing belt and lay it over top to eyeball it quickly.

All the slack needs to be between the intake cam and crank. Once I have 19 teeth between the marks you then stuff the belt behind the tensioner, doublecheck your marks and spacing, then rotate the engine clockwise 3 turns letting the spring hold all the belt tension and taking up all the slack then tighten down the 14mm bold on the idler.

jmann

You can take a plug out and lay it on the valve cover with the plug wire attached and see if you get spark. Some don't like to do that so for a few bucks you can get an inline tester at autozone, walmart, harbor freight, that well tell you if you if it is electrical.
Inline Ignition Spark Checker Again the timing belt has ZERO to do with it not firing.

deadohiosky1984

Okay so I pulled the injectors after trying to start the car several times after buttoning back up the front after rechecking timing. Fuel spilled from the two rail holes that I pulled the injector from. I am not sure if that is a sure way of knowing it spit fuel or not.

As stated earlier I get the smell of fuel from the dipstick when I pulled it so I imagine that the unburned fuel slips past the rings and gets in to the oil. Is this enough to confirm that it delivers fuel?

Stealth97

iTrader: (5)

Nope. It does not tell you if all the injectors are firing or if any of them are firing. It ran once before. Fuel in the rail does not mean much, it could be from when it ran previously or just the the priming pulse.

jmann

You still haven't seen if you are getting spark and that is the easiest of all to do. Sounds like you are getting fuel, in fact you need to be careful as you can get so much in the oil that it ignites and well blow the oil cap or the weakest outlet off. The 99 up have a fuse in the box in the engine compartment pass. side that has a 30 amp fuse for the fuel pump, I don't know if NA years have the same thing but you need to stop the fuel from injecting if you can smell gas in the oil. Check the spark!!!!!, I'll bet you don't have any. Get that cheapo tester I linked, plug the one end onto the plug [leaving it installed] and plug the sparkplug wire on the other end an see if spark jumps across in the clear viewing barrel.

deadohiosky1984

I will get on that as soon as I get the tester.

ryansmoneypit

iTrader: (6)

Wrap a wire around the plug threads, and run it to a ground location. Check for spark. No tester needed.