running on one...electrical problems driving me crazy
 

My car is running on one rotor and the map sensor reading is off.

I've got compression. I tested the coils, they're good, getting power just not all firing. I've tested the ecu in another FD and it works fine.

On my PowerFC in 'map trace' mode the marker only moves horizontally across the map. It will drop down a row or two if I get into boost, but then it continues the same horizontal only path, not moving through the load points.

I'm thinking I have an issue with the dash harness, or something it connects to, but I'm really not sure what the next step is, electrical isn't my strong suit.

https://cimg3.ibsrv.net/gimg/www.rx7...51c379cf28.jpg

I had previous issues with a pin in the B1-01 connector melting at either 1A or 1C

First off, I hope you don't have a check valve between the boost sensor and the throttle body. There should be a filter there.

Also, I assume the vacuum line to the MAP sensor is actually hooked up?

Dale

How easily does the car start up? Do you have fuel on the rotor that isn't firing? Pull the plugs and see if they're wet. I definitely would not get the car into boost running this way.

I havent been driving the car since it runs on one...i definitely wouldnt boost it that way. That was a previous issue I had before running on one rotor, I just realized that they're (map and coils) both on the pinout for the same connector so I thought I'd include that info.

Dale, I have the filter and the vacuum line is hooked up. I've tried a spare oem map, an apexi map. This issue is related to my wiring

Just trying to eliminate possibilities, I've seen people kill themselves chasing a problem when it's something simple!

Do you know for a fact it's spark and not fuel?

Dale

I took off the UIM and tested the coils out. I know for a fact I have issues with spark, I haven't ruled fuel out yet but if its tied into that harness at all I'm willing to bet I have issues there too. The sensor check screen on my powerfc was lit up with black highlights and 4.99V readings

If you're getting 4.99v readings, you need to start with that. May want to post a pic of the sensor check screen.

Dale

OK, so it's amazing the car is running AT ALL. Those 4.99 volt readings are your problem.

PIM - that's the MAP sensor

VTA1 - half of the TPS sensor

VMOP - oil metering pump, if you're not using it (like premix) no biggie, but if you are, biggie.

WTRT - Water temp

AIRT - Air temp

FUEL - Fuel temp sensor

Basically, ALL the inputs to the ECU that it needs to run aren't responding. It might be the 5v power going to all the inputs that could be at fault. There's going to be some common reason, either that or a ground isn't connected or something.

Dale

grounds have all been gone through and cleaned up where needed. extras added.

is there a way i can test that dash harness to rule it out as the problem?Do the ignition coils or any of the affected sensors tie into connectors X-05, X-07 or X-14?

^yes

Replaced connector B1-01, we've got two rotors firing now but the car wont stay running. usually just a bang out the exhaust then its off. The PowerFC sensor screen has the same readings. How do I go about testing the dash harness?

:scratch:

You most likely have a major problem of some kind with the ECU harness. I doubt it's the dash harness.

Do you have a stock or aftermarket ECU harness?

What happened between when the car was running right and now? Might be something that was done to the car.

You're in for major electrical work, and this is way more tricky than something we can tell you. You may need to find someone that can help with this problem. If none of the sensors are reporting to the ECU, you've got some common problem with that 5v feed, and that could be most anything.

Dale

x-05 & x-14
 

x-05 has : - 1st gear switch
- magnetic cluth a/p
- pressure sensor (x2)
- a/p magnetic clutch
- Injectors
- Cooling Relays
- Soloneid Valves
- 2nd gear switch
- clutch switch
- clutch interlock


----------------------

X-14 has : -Speedo input (x2)
- Rev Light Power to light
- ground neutral
- Temp gauge
- Fuel Thermo Sensor
- Cluster Ground
- Rev light power to switch
- ground 2nd gear
- ground 1st gear
- h20 thermo fan switch
- Neutral
- Electrical load input



But i personally think that if you fried the computer at B1-01 is that you had a problem with the EC/AT computer.
i would try to change that first and then the Firewall harness (not to be confuse with DASH harness).
either way you have to remove your dash if you suspect the culprit is in there.
check the resistance, you might have a short somewhere that is affecting the car severely.

All the connectors your talking about are on the Firewall harness & are **critical**.

did you perform a auto to manual swap in the past ?

Found out the wire for pin 4D - Ground Input came out of the connector. All's working now