Mazda84GSLSE

iTrader: (1)

Hello everyone. Been over a decade since my last post! Had a GSLSE then but now I have an FD..love this thing.

ANYWAY, I chanced it and bought a used one on eBay from a high rep seller. Ad stated the PFC worked flawlessly and was pulled from an FD in working condition. Before I purchased I verified serial, model number etc.

So, it came in the mail today and of course I installed it immediately after work. I reset to base map just to be sure, then went to sensor check (see attached)

Go to turn the key, motor turns over, Commander says roughly 300 RPMs. No ignition. Fuel pumping and I assume no spark. Plug factory ECU in, fired up.

I ensured the 4 wires were cut that needed to be and actually the seller had already broken the pins off. After extensive searching, I also tried the few things suggested like sequential turbo setting and PIM setting.

Just bought the car a few months ago...here's what it has:
99 spec turbos, half-assed intake by PO (2 cone filters on stock hoses)
FMIC.


Anyone have any idea what's happening? Maybe someone in the local area wouldn't mind meeting up and swapping theirs to test the unit itself? Thank you for any and all responses!

SonicRaT

iTrader: (6)

Is your throttle sensor disconnected? It's showing no voltage at all in the sensor readout. In any event, you should start with the basics and check to see if it is actually firing or isn't. And of course, fix the TPS.

Mazda84GSLSE

iTrader: (1)

Sonic, thanks for your reply.

When I step on the accelerator, the voltage goes up to .4v so I'm hoping my TPS isn't shot and it just needs adjusted. I have the TB off now to give it a good visual inspection. Physically, it looks fine. The screws were at complete opposite ends all the way to the ends which seems to like it's vibrated out of position over time.

If I can't get good voltage after adjusting, I'm going to buy a new TPS.

I do wonder though...Will the PFC refuse to allow ignition if the VTA readings are bad? The exhaust gas heat light is on so I'm assuming yes but I have limited time before this eBay seller sticks me with this...

SonicRaT

iTrader: (6)

The car should still fire, but it definitely shouldn't be at 0 like that. In any event, have you been able to confirm that there is no ignition at all? You could check to make sure no pins/etc are damaged and make sure they didn't take out any of the wrong pins.

ForeignAsian

iTrader: (9)

Well I mean if you plug in your factory one and it fires I wouldn't 100% suspect that you TPS is shot.. I'm not a pro at this by any means, I'm just here for a learning factor.. I would lean towards what sonic said and check pins/wires.

Mazda84GSLSE

iTrader: (1)

Ok, I have the sensor in good voltage range now. Car runs perfect on stock ecu, no CEL. Plug in PFC, car turned over for a long time but then started. Ran HORRIBLY, tons of white smoke...eventually died out. Any ideas?

Another weird thing...When I plug in PFC, I can hear something eletrical/like a solenoid popping & ticking...never hear anything like that on stock ECU.

Mazda84GSLSE

iTrader: (1)

Edit

SonicRaT

iTrader: (6)

Have you reset the PFC to defaults? Can't really say what the relay sound would be from, you would have to try to track it down.

Mazda84GSLSE

iTrader: (1)

Yah I have rest to base several times. tons of white smoke on the PFC only, not stock ECU, makes me think some sensor is trying to dump max fuel. At first I thought it could be coolant but that would happen on stock ECU too if the coolant seals were wearing.

I'm guessing whatever sensor is crackling under the intake is also the one the PFC uses for metering information or something. Any thoughts?

Thanks for all of your input so far yall

SonicRaT

iTrader: (6)

It could be an issue with the injector drivers and it is simply hammering the injectors (they would make noises like that).

Unfortunately, the commander doesn't give you a lot of info, but try seeing if anything looks out of the ordinary on the status pages (injector load, etc).

Mazda84GSLSE

iTrader: (1)

Thanks for the reply, Sonic. That kinda makes sense..one thing I failed to mention was there was a decent sized puddle of fuel on the ground when I was trying to start the car..and I didn't turn it over very long. Wonder where it's leaking from? I'm going to start taking everything off since my FMIC is coming in this week...Going to look all over. Probably take the intake off then turn to ON with PFC installed to find out what's going haywire.

I have air pump delete also...That shouldn't be holding me up like this though, right?

SonicRaT

iTrader: (6)

Nah the airpump shouldn't cause an issue. Sounds an awful lot like it's hanging your injectors open... not sure why it would do that outside of a short/pin issue. Can't recall if the commander tells you the injectory duty cycle or pulsewidth, but you can check that out and see if something strange is happening.

Mazda84GSLSE

iTrader: (1)

Sonic, do you think my fuel driver is potentially jacked? I read something online about soldering a new one in...I bought 2 chips they were only $3. I was going to do that just to see if maybe that was the problem.

SonicRaT

iTrader: (6)

You could probably tell by probing the injector leads, if you're getting a solid voltage reading by connecting a multimeter across both injector leads while the car isn't running, then the driver could be shorted. But, if it is bad, I'd rather deal with returning it on eBay than trying to replace the driver (if that option still exists).

Banzai-Racing

iTrader: (11)

The injectors always see constant 12V positive, the PFC only supplies the ground triggers. Sounds to me like the PFC is fried.

Mazda84GSLSE

iTrader: (1)

Yeah, after Sonic's help and a ton of reading, I'm pretty certain the fuel driver is shot. I have 2 chips coming in case I mess one up. When I bought this one used, it said it had one chip "professionally replaced." After re-looking at the sales pics with my new found knowledge, it's the fuel driver they replaced. I'm hoping they just replaced it with a defective one or something. I will find out soon enough! If if doesn't work then i guess I have to wait forever to get it back from Apexi

The many risks of Ebay!

SonicRaT

iTrader: (6)

Thus why I said to probe across both leads. If the driver is shorted and draining to ground, you'll end up reading voltage across both leads. Otherwise, it'll read nothing (as you're probing two +12V sources).

Banzai-Racing

iTrader: (11)

It would never be two 12v sources, if it were the injectors would not turn on at all.

This is a really simply test that does not require any diagnostic equipment. If the PFC is supplying constant ground to the injectors, they will be flowing constantly. Pull the LIM, turn the key and watch the injectors flow into the engine.

SonicRaT

iTrader: (6)

The driver will float the signal high when not active, so you'll see +12V on both the IGN switched power and the signal line (Stock does this too, FSM F-164 if so inclined to check). The high signal is probably just a pull-up resistor, but none the less it's still +12V. Thus, if probing, you'll see 0V across the leads, and you'll begin to see voltage as soon as ground is signaled (or shorted).

Banzai-Racing

iTrader: (11)

The test I outlined is far more conclusive and requires no special tools.

Using a multimeter on the injector connector while an injector is connected will always yield 12V+ on both wires, unless the injector is bad, since the injector is completing the circuit. This does not mean the ecu is supplying positive. The only way to do this properly is with a noid light.

SonicRaT

iTrader: (6)

The way to do this properly would be an oscilloscope (or logic analyzer), but that'd be a bit overkill. A noid light is not significantly better than the poor mans V/VRef method of guesstimating a PWM signals duty. On the technicality, both leads will not always yield +12v while an injector is connected as any applied duty cycle will lower the voltage read on the signal line. But, in any event, like I said, the PFC/FD ECU injector signals float high (typically to +12V, the FC's hang around 5V). I can demonstrate on my bench ECU's if you'd like, I've got quite the stockpile of them ripped apart for EPROM hijinks.

Banzai-Racing

iTrader: (11)

Every home mechanic has an oscilloscope.....

OP- Just pull the UIM and look/listen for flowing injectors.

Mazda84GSLSE

iTrader: (1)

Will do. First, I'm going to solder in this new fuel driver...came in the mail yesterday. If it doesn't work, then I will follow thru with these steps. I would go straight to it but that would be the third time my UIM came off in a week lol. Not feeling that again just yet. Thanks for all of your help everyone!

I'll repost with results after I solder it.