HELP!!!

Just put my Miata back together as I had it apart to mock up the coolant reroute, but now it won't run!

The car will start, and then dies instantly.

I did try jumping the pins in the diagbox to force the fuel pump, and it will stay running only with this, and if we keep the key in the start position.

Anyone got any ideas? 10 years working with these things and I am STUMPED!!!!

 

Just to make sure I understand correctly, fuel pump jumpered on with the key cranked into the starter position or in the run position?

 

Key in the START position and it will run! Otherwise It just starts and dies!

 

ignition switch ?

 

More details are needed.

With the key in the "run" position, are the dashboard instruments (odometer, etc) working?

To be sure I understand correctly, when you say Does this mean that it will stay running if you either jumper the fuel pump or hold the key in "Start", or do you have to both jumper the pump and hold they key in start?

 

Forget about jumping the pin.. As long as I hold the key in the start position it will stay running. As soon and i let go of the key it DIES!

 

Everything works when the key is run.. but the car dies unless I am in the Start position.

 

if your key is in the start position, then it's not really running.

 

did you hook the maf back up?

 

Never disconnected the MAF.. That is the screwed up thing.

When the car is in the start position I can rev the motor and do whatever, It certainly is not the starter keeping the motor alive.

Otherwise it starts.. Revs to 1500rpm for 2 seconds and then dies.

 

Fuel Spark Compression Time
Which are you missing?

 

Did nothing and now it is running!!! What the **** it going on!! I'm gonna bleed the cooling system and then I will turn it off. It is puuuur at 850rpm now! I don't like the fact that I did nothing and it runs now!

Yikes!

 

ignition switch?

 

That is my guess if it starts ******* up again... Anyone know if the ignition switch from a 97 is the same as my 2000? I have access to a scrap 1997 in a few days.

Lets hope this sorts its self out.. I put the car back together so I can install my Megasquirt.

 

RUnning for 10 mins.. I'm gonna turn it off and try starting it again in a few minutes.

 

Started no problem again! Urgh?

 

I understand- it fires when you're holding the starter on. But even if you jumper the fuel pump on (F/P to GND) it does not stay running when you release the key to the run position. I want to be super-clear on this point.

Ok...

Can you hear the fuel pump running when it is jumpered on and the key in "Run"?

On the NB, only the main relay can power the fuel pump, even when starting. So if yes, then the Main Relay is ok, as are the INJ fuse, the Main fuse, the IG KEY fuse, and the ENGINE fuse.

The Main Relay is not controlled by anything. It turns on whenever the key is in the IG1 or Start position. It is *possible* that the IG1 contact is bad, but I doubt it. Do the turn signals (not the hazard lights, the turn signals) work when the key is in the "run" position? If so, then the keyswitch is fine. (they are on the same contact)

Logically, the problem must be with something that you moved / touched while you had everything apart. What all did you touch, exactly?

It seems possible that the ECU is not seeing some input that it wants in order to run the engine. If you have an OBD-II scanner, that might provide a clue.

I'd start by triple-checking the CLT sensor, the IAT sensor, the MAF sensor, and the cam sensor. These are the inputs that the ECU absolutely requires for normal running, but can probably live without for starting.


edit- looks like I let that message simmer too long befor hitting "Send".

 

Little tiny baby jesus did it for you

When you said about keeping it in the start position, did you mean like actually hold the key all the way forward and it would run? If I had to guess I would say ignition is messed up then.

Vash-

 

The car is now running perfectly and I am letting it run to charge the battery for a little bit.

* have a funny feeling it maight be related to a low charged battery as i boosted it and then it started running ok. Ummmmmm.....

Sound stupid... But newer cars are messed....

 

I'm 99% it is a battery issue... Left the car outside in some 0 celsius nights all week on a very low charge and it is doing the same thing. Just pulled the battery out and I am charging it in the garage.

Hopefully it works.. I gotta start driving this car to get a charge on it. Hopefully it stops raining soon.