37 replies to this topic

[Gary Moser]

trying to get an 02 SM with vvt running. Last spring apparently it quit and several people have worked on it trying to get it to run.

 

new plugs installed, fuel pressure checked, new EGI relay installed

 

ignition fires once, only get one spark then nothing

 

originally believed it was the imobilizer circuit, replaced the imobilizer, computer and chipped key, a matched set from another car, same result

 

replaced camshaft position sensor and crankshaft with one from a running engine, new camshaft sensor connector installed

 

no matter what we do all we get is one spark then nothing

 

[mdavis]

Assume the ring around the ignition switch is attached and has continuity.

[Gary Moser]

yes, made sure of that. when we replaced the computer, immobilizer and key we used the complete ignition switch from the donor car

[FTodaro]

So if you pull off a plug wire, and crank it, it sparks once and then quits?

[mdavis]

Coil packs are on top of the plugs.  I assume those are ok?  Timing wheel on correctly and adjusted ok?

[FTodaro]

Coil packs are on top of the plugs.  I assume those are ok?  Timing wheel on correctly and adjusted ok?

What I am suggesting is you pull a plug (that is not under the coil pack) ground it out and crank it over to confirm you are getting spark.

[davew]

It has been said many times. Diagnose rather than throw parts.

 

You say you have fuel pressure, do you have signal to the injector (commonly called NOID)?

 

Do you have confirmed spark on 1 cylinder, 4 cylinders???

 

Do you have compression?

 

Do you have substantial cylinder leakage?

 

Do you have any fault codes? Clear and try to start again to confirm fault codes.

 

What is the history of why it stopped running?

 

Give us the info and we can help. Without info we are stabbing in the dark

 

Dave

[Gary Moser]

timing wheel on and correctly adjusted

spark tested by pulling wire #1 and attaching a spare plug, one spark only

fuel pressure within spec

car trailered to track and would not fire, ran fine at the shop

[Gary Moser]

will crank until the battery dies

 

only code is 1 which as best as I can determine has to do with the immobilizer not communicating

[Michael Novak]

Gary,

 

pm me your phone number and I will send over a short video of my car doing the same. 1 spark only----Try having someone crank the car and SLOWLY wiggle all the harnesses. My car has a bad wire in the end of the harness where it comes to the airbox sensors...  All fine then wham dead..  

 

Mike Novak

 

 

[Gary Moser]

will be working on it Friday, will run a bunch of tests and post the findings

[Gary Moser]

TPS is 4.93v, within specs of 4.5-5.5

 

Crank Position Sensor at 0.027, specs 0.020-0.059

 

does not fire using starter fluid

 

checked grounds by unplugging connectors and metering them

 

coils meter to specs

 

shook wires while being cranked

 

unplugged immobilizer and checked voltages at the connector per manual

[Ron Alan]

Fuel, spark, compression...which one are you missing?

 

No idea about a NB2 but I had a similar start and die situation with a 95. Was losing ground pulse to injectors...in a 95 this is provided by the coil. 

[Bench Racer]

yes, made sure of that. when we replaced the computer, immobilizer and key we used the complete ignition switch from the donor car

Do you have a second/different key of the pair to try.

 

Copied info:

 

"I called the mechanic. As soon as I mentioned the immobilizer, he said "I never thought of that, but, yes, the immobilizer could be the reason." I asked for his suggestion to resolve. He then described what would be the solution: Find all of your keys (I have three), then test each one. I might be necessary to lock/unlock the door using the door lock (not the remote lock of the key Miata fob), to as input into the system. For good measure, I unlocked the car using one of my other keys, then, as soon as I cranked the motor using the same key as I used to unlock the door, it sprang to life! I drove the car today with no problems.

 

As it turns out, the key I had been using exclusively over the past few days was faulty. The IC embedding into the molded plastic key head had failed. Evidently, it was borderline functional, until it finally failed. Each of the times the Miata could not sense the IC, it considered the key to be illegitimate, thereby triggering the anti-theft characteristics of the immobilizer. My other two keys, work great! This has been a real head-scratcher. Of course, all problems make perfect sense, once the root cause has been identified."

[davew]

I have heard, and no I have never tried it, that there is a way to bypass the anti-theft device. I would search the internet forums and see what you find. Posting it here may help someone sometime.

 

dave

[Bench Racer]

Following Dave's lead ^. Threw these words in a search engine (one that ran ), "2002 miata bypass the anti-theft device". After clicking and opening, the video below was selected, after video opened, on the right hand side of page came up a bunch of interesting videos on said subject, including a Ford Focus temperature gauge failed sending message to the ECU hence no spark, along with this video key work around from a Cadillac where the guy had no key.  Cadillac or Miata????

 

[Gary Moser]

only have one origianl key to the vehicle and only one for the second system we tried which supposedly came out of a running car. can't use the key to unlock anything since the doors have been gutted

[Steve Scheifler]

Fuel, spark, compression...which one are you missing?

No idea about a NB2 but I had a similar start and die situation with a 95. Was losing ground pulse to injectors...in a 95 this is provided by the coil.

Sounds like spark, other than the one pop on the first rotation. Is that a major clue or is the single spark just an expected discharge of a capacitor that gets voltage at key-on?

Is there anything else monitored by the ECU which would prevent spark if it fails?

[Gary Moser]

started a new job and have not been doing much to the car. put the car back to "stock", everything points to needing Mazda specialized testing tool.

 

have tested voltages and grounds on all connectors I had specifications for in the manual.

 

car cranks strong, has fuel pressure but no sign of spark or fuel injectors being fired

 

next step is to try to find an experienced Miata mechanic with the proper testing equipment

[Bench Racer]

Presumed you tried fire to plug on #1, try same on 2, 3 and 4, see what results.