santorkyle

Ok guys I have been having small issues with the car not reving all the way but now I was driving, got on the car a little bit and it just shut off, I coasted to the side of the road, took out the CAS and unhooked the battery and when cranking I wasn't seeing any tach movement, but it finally started after a few minutes and drove back to my shop and it shut off again a few minutes later and I can't get it to start to save my live.

What I have done so far- Replaced a couple ground on the block and checked with a good working ECU to make sure that was not the issue, checked and I am not getting fuel pulse or spark but the car cranks normal, I OHMed out the CAS and the OHM is normal but does not really mean much, any ideas would help, I have been driving without really any issues for a month and then just shut off...

texFCturboII

iTrader: (17)

A few things come to my mind, one being the Main Relay, check to see that everything is nice and tight and no wires loose or burnt up. This sounds like an issue I had with my T2 once, and the Main Relay was the issue.

Next in my mind is the Fusebox, particularly the EGI fuse and wiring to it. Take a look there and see what's going on as well.

santorkyle

Ok I ordered another CAS because I had no fuel or spark, but I will check the main relay as well, I checked all the fuses under the hood and everything is fine and so are the wires, I spent 4 freaking hours checking and OHMing out wires and stuff

santorkyle

LEADING IGNITION Consider the leading ignition coil with igniter. The B/Y (black with yellow stripe) wire is the 12V primary current supply (from main relay). The G/Y (green with yellow stripe) carries the ignition timing signal (IGT-L) from the ECU

I assume that means that since I am seeing 12v at the coil with the key on, then the relay is good?

satch

iTrader: (1)

And the B/W wire powering the ECU needs to be good as well. There's a green check connector near the leading coil with a B/W wire and it should have voltage as well as w/key to on. You could also have a faulty ground to the Main Relay which would cause it to work some times but not all the time especially if the car runs over a bump. When the car dies do you lose power to run certain items like the wipers or turn signals w/key to on. This will tell you if the ignition switch is cutting out.

santorkyle

Well rightnow the car is dead in the water, won't even start again, but I have power to the coils and my wiper blades and headlights and everything still work, just no spark or fuel, but I will check the ecu for power as well, I already re did all my grounds to the car and made sure they were not corroded.

satch

iTrader: (1)

W/key to on check for voltage on the Brown/White wire at the TPS. If it has about 5 volts then the ECU is powered on.


And the ECU may not be properly grounded.

satch

iTrader: (1)

The most important interior fuse as it relates to starting the car is the Engine fuse but if your Main Relay is working then this fuse must be good.

The wire at the TPS needs 5 volts w/key to on. If it has no or very little voltage then either the ECU is not powered on or there is a short in the wire being tested at the TPS and the car would not start if so.

You can pull a spark plug wire off at the leading coil and rest the boot up against the coil bore, and w/key to start you should see spark.

santorkyle

Ok so I need to check the TPS for 5 volts, and I have a spark tester that I just touch the wire with and it will pulsate with the spark pulse and it doesn't budge, but I'll pull a plug out just to make sure my tester isn't bad. I am a manager at a nation wide mechanic shop so I have plenty of tools and alldata to use if I need anything, just always been a DSM guy this is my first rotary , thanks for the help sofar satch, I will update the situation in a couple hours.

santorkyle

Ok so I checked, the check connector by the coil has power on the B/W wire, but the TPS Br/W only has .25 volts, so would you suspect a bad wire or the ECU not being powered on?

satch

iTrader: (1)

S4 or S5? If the Brown/White wire has .25 volts w/key to on then it points to this wire being grounded. This wire powers a number of engine sensors and one of them is the AFM. So, unplug the AFM and recheck the wire and see if the voltage returns to 5 volts w/key to on.

santorkyle

Yes it is a s4 and yes it is Br/W wire shows .25 volts

santorkyle

Ok satch, i unplugged the air flow meter, re tested at 4.99 (5v) and then started the car with the afm un plugged and obviously dies right out so I hooked the afm back up, and the car starts and runs..What are your suggestions now all might one! lol, thanks by the way for everything so far.

texFCturboII

iTrader: (17)

I'd say you've got a dodgy AFM. Or the wiring at the connector, or to the AFM connector is in need of inspection and/or repair. Let's see what satch says, I hope you've found your problem.

satch

iTrader: (1)

I agree.

santorkyle

I have tested the wires on most sensors and OHMed out the wires between sensor and ECU connection and all seem ok and with in limit, I bench tested the AFM and everything was with in spec EXCEPT the V2Ref (voltage reference) was off by a lot

satch

iTrader: (1)

Then that is likely the problem.

santorkyle

Ok well I am getting the car towed home from the shop so I can work on it and just let it sit for a while until I can find a good AFM, if I unplug it and plug it back it, it will start and drive for a few minutes down the road and then shut off again, is that because the AFM stops sending voltage signal to the ECU and cuts off the fuel pump and everything?

texFCturboII

iTrader: (17)

Yes, without signal from the AFM the car shuts down. As far as getting to work for a few minutes... maybe things are arc-welding together until you hit a bump in the road???

santorkyle

I just need to know what I need to test to make sure its %99.9 that it is a bad AFM or a short in the harness, I have all day tomorrow and a FLUKE volt meter and a power probe and a 2 car garage and 24 hours to play with and I downloaded the whole car's electrical system diagram.

texFCturboII

iTrader: (17)

If the AFM itself isn't spec, then that should be your problem.

Since there is only one pin at the ECU for 5vref for all those different sensors, you would need a little more than 24 hours to rip the harness apart looking for shorts. A quicker solution would be to get hold of a good AFM, swap it in and see if it works. If it does, great! If it doesn't, you've got a short in the harness.

santorkyle

Ok because the OHM for the 5vref was at like 1950 and supposed to be around 700 based on*outside temp, i wont even touch the car until i can find a known good used one or buy a new one.

santorkyle

Ok sacht back to the forum post's..So thanks to sacht we have figured out what happened. The car shut off while driving but I could unplug the AFM and plug it back in and the car would start for a few minutes then shut off, so I opened the top of the AFM and looked inside at the electrical board and found a shorted wire touching the board. I cut it off re soldered it down and its fixed...Now a issue I have been fighting since I bought the car is it won't run right after the car drives for a few minutes, now I have a full racing beat exhaust so no cat's and I replaced the thermo sensor and thermostat but sacht was saying something about voltage to the ECU if you could re post that for me sacht I would appreciate it.

satch

iTrader: (1)

Pin 2I should measure 2 to 3 volts w/key to on when the engine is cold and close to .5 volts w/key to on and the engine fully warmed.

misterstyx69

iTrader: (142)

Who is this guy "SACHT"??
.only fitting to get the Guy's name right..after all he is helping you!