Hey Guys,

Trying to diagnose what my problem is.. I can get the car to start and run for a few seconds, but then it suddenly dies every time..

The only thing that's odd that I can see is that I'm reading ~0.4 PSI of vacuum while the car is off.

I'm using a Banzai adapter without resistors, FD fuel pump, stock N374 550cc primaries, ID1000cc secondaries, Triumph AIT sensor, GM 3-Bar pressure sensor, Banzai 550primary/secondary base map, on an NA engine harness (all the solenoids removed except for fuel pressure, knock sensor patched into the Banzai harness using a shielded wire), ACV blocked off, full RB REV TII exhaust, no narrow band O2 connection.

Timing looks mostly right, though my Dad said that it was showing the leading and trailing on the same mark [Yellow IIRC] while cranking.

It sounded like it wanted to catch almost the entire time, and I'm not sure if it was coincidental, but after setting the primary injector size setting in FC-Edit down to 430cc it seemed to start easier..

It also died quickly once when I tried to give it more throttle [again, may have been coincidental]

I would try my unknown condition N370 ECU/Pressure sensor/AFM, but I don't have a stock intake tube, nor proper couplers/adapters to fit it without being super ghetto [say, duct taping it], not to mention I'm not sure where exactly it went.. [Moved everything except what was in the garage from my parents' to my house]

Attached is a picture of the Commander with the car not running and set to ON, also copies of the base map I've been trying to use and logs...

At the moment, the only suggestion I've gotten has been to convert to an FD pressure sensor (apparently they're a lot more reliable)

Any ideas?

 

There is nothing wrong with the map sensor.

Change your secondaries to 1000, since you are running 1000

Verify that you have the injector connectors attached to the correct injectors. I see this all the time, where people have the connectors swapped and the car will not start.

 

Hey, thanks for the reply!

So ~-0.4 PSI is within the error margin for the sensor?

I'll set them to 1000cc, though I thought that that probably wouldn't matter for startup (does the PFC fire all 4 throughout the rev range?)

How can I tell if I have the injector connectors on the correct injectors?
Looking at the pictures I have, it looks like I connected the longer ones to the rear injectors.

And here's a video of how it acts when it almost stays on:
http://www.youtube.com/watch?v=3oRvw...ature=youtu.be

 

The PFC does not read PSI in vacuum or boost. The map sensor will read a small amount of vacuum, which will vary depending on your elevation, it will read closes to 0 at sea level.

It does not fire all the injectors, but you may as well set them up correctly, since they are in you car and you have a DL.

Can't tell anything about your wiring from your pictures, look in the FSM and very the connectors by wire color.

From your video you are running on one rotor. Verify compression before doing any more troubleshooting. If compression checks out you have either got the injector connectors wrong or a stuck injector.

Easy test, apply voltage to the primary injectors and verify that they click.

 

Well yes, I know that it was reading in mmhg (-26, IIRC) or voltage to be technical.. But I had no idea what an mmhg was until I converted it.

Good to know. I'd heard that FDs didn't batch fire the injectors so I wasn't sure if they'd done away with injector staging as well.

hehe, don't underestimate the thoroughness of my pictures. Per this attached picture, and this thread: https://www.rx7club.com/2nd-generati...start-1049213/
Light green with black is the rear primary injector, so that's correct. (I knew questions about vac routing and wiring might come up, so I tried to be super thorough).

I did have the injectors sonic cleaned and tested before installing them, but it was a while ago..

This is a fresh rebuild, so it's possible something is stuck (new housings, ceramic apex seals, clearanced side seals.
I'll double check that I'm seeing compression.

 

The cleaning solvent that most injector service companies use will cause injectors to stick, especially if they are allowed to sit. I have received injectors back from 3 different well know injector cleaning companies that we're stuck open or closed out of the box. All the injectors were functioning perfectly when they were sent out.

After sending injectors out for years and seeing little to no improvement in flow in 100's of injectors, yet having numerous failures that have led to hours of rework, we no longer send injectors out.

 

Compression checked out OK. Nice even pulses via a piston compression checker.

Put a fuel pressure gauge in line from the filter to the rat's nest, and under cranking we got ~45 PSI, but as soon as it started to actually run, the pressure dropped to nearly zero and then the stall...

So I jumpered the fuel pump check connector and got it to run for a solid half hour. When I tried to ease it down to idle, it sounded rough [~1K RPMs] and then died...

Still reading vacuum when the car is off, even after swapping to an FD sensor. [~0.5 PSI vacuum]

And I seem to have some small oil leak [or there's a lot of Crisco oozing off, lol...]

Any idea what would be shutting the pump all the way off as soon as the car starts?

 

I told you there was nothing wrong with the map sensor.

The PFC is only priming the pump, you have an issue with the fuel pump circuit. Did you buy the PFC used?

 

Touché!
hehe, worth checking though.

I've been recommended to bypass the fuel pump resistor relay, hopefully I can do that without terribly much trouble.. [I really hate cutting wiring if I don't absolutely have to]

Yep, bought it used from a friend. Have you seen used ones read sensors 'off' before?

 

The sensor is not "off", the map sensor is reading correctly

I have seen used PFCs with fried fuel pump circuits.

 

No dice on the resistor bypass.... >_<

Checked the sensor readings by plugging it into my friend's FD for a minute, but it read the pressure sensor the same. Didn't try to start it up in the FD because I didn't bring the Datalogit along..

Going to make a post in 2nd Gen Technical, seems more like a general FC issue rather than a PFC one.

 

Could have just initialized the PFC and tried to start the car, no need for a datalogit. You really need to verify that the PFC does not have a fried circuit.