Need some advice

[Coty]

I just got my brothers 240sx running. Heres the list 89 nissan 240sx with black top sr20det. Brand new engine harness. 300zx maf sensor.

My history: I am a auto technician and master ase certified. I have a heavily modded dsm (haha) and I am building up my brothers car as of now. I am not a noob so please only constructinve comments.

I got the car all together yesterday and went to start it. Just cranked, I checked fuel and had fuel. I then checked spark which was also there. Then as I was going over the wiring I found that the maf was hooked in wrong. Power and grounds were switched. Fixed that and the same problem no start. Then I checked the cam angle sensor and holy **** it was off. We just got this engine from Nagasaki motors and the cam angle sensor was on wrong. I thought to myself that was a dirty, dirty trick. I matched up the dark marks on the chain with the marks on the gears and aligned the cam angle sensor right. Stuck it in and it fired right up. The problem now is that its running extremely, extremely rich. It keeps fouling out the plugs. I am using a hks afr to tune out the z32 maf but no matter what I do with it, it doesn't seem to make no difference. If I unplug the maf sensor it runs the same. But its getting the 2 grounds, 5 volt reference, and the 12 volt signal. I just can't figure out why its running so damn rich. Can a fugged up cam angle sensor do that? I have a brand new one in a box in my brothers room if thats it. Did we fry something when he hooked up the sensor wrong? (all the wire voltages checked out so I did not think this was the problem) Its extremely black smoke, I can't breath when I am around the car. I ohmed out the coolant temp sensor and that checked out fine as well. Is there anyway that I could of put the cam angle sensor 180 degrees off? I need some help please does someone have and advice or past experiences they could lead me to something here.

Thank You

[rogoman]

Could be one of several problems:- temperature sensor wiring; check pinouts to the ECU- FPR may be defective causing very high fuel pressure- ECU may be defective- the HKS AFR may be defective

I can't see where the CAS would cause a very rich mixture since the motor starts right up.

[480sx]

Your SR has stock injectors correct?

Why dont you try it with a stock MAF. Since your not pumping massive hp's with it yet, the stock MAF is probably fine for your application.

Try to isolate where your problem is coming from. If you disable your AFR, put in the stock MAF, and it runs fine, then you know your problem is either with the MAF or the AFC.

Also, do you have a WBO2? If you do, hook it up and check to see if it does anything to your AFR's when you mess with the dials.

[Coty]

Could be one of several problems:- temperature sensor wiring; check pinouts to the ECU- FPR may be defective causing very high fuel pressure- ECU may be defective- the HKS AFR may be defective

I can't see where the CAS would cause a very rich mixture since the motor starts right up.

I will check the coolant temp sensor pinouts at ecu. Its a brand new harness so I hope its getting there.

If the maf power and grounds were switched would that kill my ecu? None of the wires heading to it are burnt or anything like that. No matter what I do with that hks afr nothing changes. Should I just get apexi neo so I can change the voltage in and out with that? I don't think I can do that with that hks. The reason I don't think its maf related is because doesn't the 300zx make it run leaner not richer.

Tonight I am going to check for stuck injector and test the circuits with my noid light. I have a vacuum pump so I will check the fpr and see if its holding vacuum.

[Coty]

Your SR has stock injectors correct?

Why dont you try it with a stock MAF. Since your not pumping massive hp's with it yet, the stock MAF is probably fine for your application.

Try to isolate where your problem is coming from. If you disable your AFR, put in the stock MAF, and it runs fine, then you know your problem is either with the MAF or the AFC.

Also, do you have a WBO2? If you do, hook it up and check to see if it does anything to your AFR's when you mess with the dials.

I wouldn't want to put a wbo2 through this abuse.. .Haha jk It is so damn rich, its like the injectors are stuck wide open. I can clean the plugs and run them again and within seconds they are all fouled out again. How does your guy's car run when you disconnect the maf?

[480sx]

I really dont know anything about the HKS AFC, but it might be that it wasnt designed to run non stock Mafs. I have seen them before, they just have dials that control AFR's at dif RPMs right?

You dont really need to spend the extra cash and get a Neo.. The SAFC2 does the exact same thing but it doesnt have all the flash that the Neo does. Your choice though, but before you spend the cash on a different AFC you should do some research on the one you have. Check to see if it can run upgraded MAF's.

[Coty]

It can run upgraded maf, but its just not as user friendly as a safc. If you would pull the maf plug off your car running would it running extremely rich?

[180fan]

pulling the maf will limit the rev and make it run richer but not enough to kill the motor. it'll be in safe mode.

The above suggestions would be the ones to follow. Pull any maf signal modifier and then run it without a maf to see if it will at least idle since that seems to be the biggie for now.

From there, then check over the other stuff like the tps and replace the cts. Then check over the timing. A CAS will only effect your ignition. You'll be able to sniff this out either at 1. the tail pipe or 2. with a timing light.

[Coty]

pulling the maf will limit the rev and make it run richer but not enough to kill the motor. it'll be in safe mode.

The above suggestions would be the ones to follow. Pull any maf signal modifier and then run it without a maf to see if it will at least idle since that seems to be the biggie for now.

From there, then check over the other stuff like the tps and replace the cts. Then check over the timing. A CAS will only effect your ignition. You'll be able to sniff this out either at 1. the tail pipe or 2. with a timing light.

Is there any way to pull codes on these things?

[180fan]

well the cts is a replaceable item. it's less than 20 bucks at your local auto parts store. With all the sr's i've torn down, they all had gunk coating the tip of the cts. When the motor is out, I make it a point to replace that bugger.

the tps, you can do without the motor on. it's a calibration with a pair of needles and a multimeter. Not too bad a job. use of an afc can make this part actually much easier since it can read throttle voltage as one of it's monitored stats.

the cas, you can have the ecu run the test on it ala the screw on the back of the ecu. it's not necessarily going to find it though. I've had some of the most rotten luck with the ecu's sniffing out codes for me.

[Coty]

W

well the cts is a replaceable item. it's less than 20 bucks at your local auto parts store. With all the sr's i've torn down, they all had gunk coating the tip of the cts. When the motor is out, I make it a point to replace that bugger.

the tps, you can do without the motor on. it's a calibration with a pair of needles and a multimeter. Not too bad a job. use of an afc can make this part actually much easier since it can read throttle voltage as one of it's monitored stats.

the cas, you can have the ecu run the test on it ala the screw on the back of the ecu. it's not necessarily going to find it though. I've had some of the most rotten luck with the ecu's sniffing out codes for me.

What do you do with the screw on the back of the ecu?

[Backtoblack]

I have never used it, so correct me if im wrong but it turns your ECU into diagnostic mode when you turn it one direction or the other. Take your ECU out of its cubby, you dont have to disconnect the harness. Next, find the screw, it will be labeled and will tell you what direction to turn it till you get to the diagnostic mode.

Then i guess you either hook a code scanner up to it or read CEL flash's to pull the codes? Im not really sure about that last part however, just a guess.

[Coty]

I have never used it, so correct me if im wrong but it turns your ECU into diagnostic mode when you turn it one direction or the other. Take your ECU out of its cubby, you dont have to disconnect the harness. Next, find the screw, it will be labeled and will tell you what direction to turn it till you get to the diagnostic mode.

Then i guess you either hook a code scanner up to it or read CEL flash's to pull the codes? Im not really sure about that last part however, just a guess.

Ok thank you. I will do that tonight, it should flash. I'll keep you guys posted with what code I get.

[Coty]

Got a mafs code. Open or shorted maf circuit. I am ditching the stupid hks afr and getting a safc setup. I think the reason is that I can't change the input and output voltages of the hot wire maf.