Miata Turbo Forum - Boost cars, acquire cats.

Miata Turbo Forum - Boost cars, acquire cats. (https://www.miataturbo.net/)
-   ECUs and Tuning (https://www.miataturbo.net/ecus-tuning-54/)
-   -   Help isolate fuel problem (https://www.miataturbo.net/ecus-tuning-54/help-isolate-fuel-problem-77761/)

hustler 03-24-2014 04:49 PM


Originally Posted by Boris (Post 1114613)
A grounded out spark plug will tell you if you have fire.

Pull out all the plugs, disconnect your coils and turn on your fuel pump.
When you crank, do you a see any extra fuel or a mist of fuel coming out of the affected cylinder ?

Do I need to do this if I hear them opening? I did the test with the fuel pump off.

Originally Posted by Oscar (Post 1114614)
Finger on coil and output test mode :idea:

I would use my penis but I don't have much feeling left in that thing from all the dolphin "relations".

Originally Posted by Reverant (Post 1114605)
Injectors 1 and 3 share the same driver on a 1.6L. The same goes for 2 and 4.

So if this was an injector driver inside the ECU, two cylinders would be affected at the same time.

Cool, but does it matter that this car has sequential fuel? The test tells me everything is working properly on the fuel side. What are your thoughts on the coils and do you have a recommended testing procedure?

Thanks for the help, all.

Boris 03-24-2014 05:01 PM


Originally Posted by hustler (Post 1114624)
Do I need to do this if I hear them opening? I did the test with the fuel pump off.
.

Do you know if they are closing ?

Had a fuel pressure regulator go bad once and all the extra pressure would blow right by the weakest injector putting out the flame.

Reverant 03-24-2014 05:01 PM

Have you converted to sequential fuel?

If so, have you performed the test I described (replace all 4 injectors with light bulbs, test each driver/"injector" using the output test mode.

Do you still have the stock 90-93 coils?

hustler 03-24-2014 05:27 PM


Originally Posted by Reverant (Post 1114633)
Have you converted to sequential fuel?

Yes

Originally Posted by Reverant (Post 1114633)
If so, have you performed the test I described (replace all 4 injectors with light bulbs, test each driver/"injector" using the output test mode.

No, it's $100 so I was trying to get around that. I guess it's time to get out my wallet. Listening for the audible clicking noises from each injector is insufficient for a test like this?

Originally Posted by Reverant (Post 1114633)
Do you still have the stock 90-93 coils?

No, this is VVT with VVT coils, son.

hustler 03-24-2014 05:33 PM

Is this what I want? I'm not sure which plugs into the EV14 from the pictures and searching is failing me.
Kent-Moore J-44603 Noid Light (Bosch 2) (J44603)

Reverant 03-24-2014 05:51 PM

Wow, such expensive. doge_face.jpg

Ok get just one to test each driver individually, and if need be, get more.

hustler 03-24-2014 05:53 PM


Originally Posted by Reverant (Post 1114648)
Wow, such expensive. doge_face.jpg

Ok get just one to test each driver individually, and if need be, get more.

Very thanks for the help.

karter74 03-25-2014 09:31 AM

Try swapping the injector with another cylinder to see if the problem follows that specific injector or that injector output.

hustler 03-25-2014 12:26 PM

Why are you guys focusing on fuel and not the coils? Serious question. The injectors seemed to work normally, audibly in test mode, the coil clearly did not in test mode.

curly 03-25-2014 03:04 PM

Do you have a cheapo HF compression gauge?

hustler 03-25-2014 04:53 PM


Originally Posted by curly (Post 1114921)
Do you have a cheapo HF compression gauge?

One coil lead reads half the voltage of the other and you think the engine is blown up?

karter74 03-25-2014 04:58 PM

You said it is getting spark. My assumption is if spark is functioning correctly, you're dumping in too much fuel. Even if you can "hear the injectors" who is to say the injector is coming completely closed/getting hung open?

Swapping bad cylinder injector with another and having the problem on the same cylinder would immediately rule the whole fuel thing out. Then you can say without a doubt it's a spark problem.

Or your engine is blown.

curly 03-26-2014 12:03 AM

It's you...so yeah

Oscar 03-26-2014 03:37 AM


Originally Posted by hustler (Post 1114940)
One coil lead reads half the voltage of the other and you think the engine is blown up?

Then swap coils? If shipping back and fro' weren't a pain in the dick I'd lend you my set of VVT coils.

hustler 03-26-2014 08:07 AM


Originally Posted by Oscar (Post 1115065)
Then swap coils? If shipping back and fro' weren't a pain in the dick I'd lend you my set of VVT coils.

The wires going to the coil read 2 and 5v, so swapping the coils won't matter, and I"ve already swapped them around with my spares.

rleete 03-26-2014 09:07 AM

So, wiring before the coils. Pinched wire, bad solder/crimp joint, faulty connector.

Oscar 03-26-2014 09:42 AM


Originally Posted by hustler (Post 1115084)
The wires going to the coil read 2 and 5v, so swapping the coils won't matter, and I"ve already swapped them around with my spares.

Now I get it. Time to break out the DMM.

Miater 03-26-2014 11:36 AM

I can clean and flow your injectors for you if need be.

hustler 03-26-2014 05:26 PM


Originally Posted by Oscar (Post 1115118)
Now I get it. Time to break out the DMM.

Dude, I measured with a multi-meter, lol. I guess it's time to chase wire.

hustler 04-07-2014 12:23 PM

I used a spark-plug light to determine that each coil is at least activating the light.

So today I used the multi-meter to determine that each injector is firing in test mode with similar voltage numbers. (The light I bought won't work, so I might have to buy another.) Injector A is the only injector that made a mist of fuel shoot out the spark-plug hole when using test mode, the rest did not but they are clearing squirting fuel. Time to rewire and replace injectors?


All times are GMT -4. The time now is 04:39 PM.


© 2024 MH Sub I, LLC dba Internet Brands