a couple of questions about my fault codes

[flyboyx]

to make a long story short, i finally got my diagnostic port working and was able to read my fault codes today. here they are posted below. any input is appreciated.


i have a shitload of codes. since i have stock obd2 wiring and dme from an mz3 roady, the directions with my peake scan tool say to use chart #2. the codes are:

e4- o2 sensor adaption limit cyl 4-6
e3- o2 sensor adaption limit cyl 1-3
4f- after cat o2 sensor heater cyl 1-3
37- precat o2 sensor heater cyl 4-6
19- precat o2 sensor heater cyl 1-3
3d- after cat o2 sensorheater cyl 4-6

these above, i am not that concerned about because i don't have the exhaust hooked up after the manifolds. this means the rear o2 sensors aren't even plugged in. i think all of those will go away once i get my exhaust modified and hung on the car.

there are 4 more codes for me to worry about though.

45- electrical fuel pump relay. i am going to have to look into this one, but i am pretty sure that the e30 has its own fuel pump relay on the body. i know that i have 50 psi of fuel at the rail when the key is on. i was thinking this sounds like a lot. i have a hanes manual that states that e36 fuel pressure should be 6 or 7 psi at idle and 10 psi above a certain rpm.

32- evap systems running losses valve. i am not sure if this is the electrical valve in front of the throttle body or something on the fuel tank.

06- fuel injector cylinder 1. does this really mean i have a bad injector?

08- air mass sensor. i can't imagine that my air mass sensor is bad, but what the hell do i know?




i think if i get the last 4 on the list taken care of i'll be good to go.

[MIKe30]

Wish I could help more, other than being pretty sure the evap system is what is connected to the charcoal canister. Hope that helps.

How did you get your diagnostics working? My peake tool doesn't seem to get any power when I plug it in. Don't think my stomp test works anymore either. I am also obd2.

Good luck.

[matt]

The running losses valve is AKA the 3/2 valve. It connects to the fuel pressure regulator under the driver's feet. (on an e36)

Check your injector connections, you may have a loose connection on Injector 1.

It doesn't matter if your MAF is bad or not, if you have that code, your car is in limp mode running off MAF backup maps. This is the biggest deal of all your codes.

Your fuel pressure should be 51psi minus manifold vacuum. 6-7psi is correct for a vehicle with a carb, maybe?

Oh and clear all the codes and see what comes back. Does the car run OK?

[flyboyx]

Wish I could help more, other than being pretty sure the evap system is what is connected to the charcoal canister. Hope that helps.

How did you get your diagnostics working? My peake tool doesn't seem to get any power when I plug it in. Don't think my stomp test works anymore either. I am also obd2.

Good luck.

ok mike. here is the deal. i saw your post a couple of days ago on the service interval reset thread. as you have figured out, one of our predecessors screwed up the #19 wht/gn on their diagrams and has been handed down and so on. #19 is the service interval reset in your diagnostic port pin #7. this goes to the white blue wire(pin 11) on the e30. i assume you already have this figured out.

what no one else seems to know or have posted on the forums is the following: the peake reset tool has six pins that fit into the diagnostic port. the way we have them hooked up there isn't a power source for the tool. by comparing my wiring diagram to the the peak tool, i found that pin 16 in the diagnostic port goes through the x20 pin #22 which is a green/white at the diagnostic port and the x20. since i pulled out and traced all of the wiring from my z3, i know that wire went to a 10 amp fuse in the fuse box.

so, to make a long story short, connect that #22 green/white to 10 amp fused power and presto! all of this in in my swap blog if you want to check it out there.

also, there are three important diagnostic wires in the harness. wt/gn, wt/vi, and and wt/ylo. somewhere on line today i found a diagram for the diagnostic port and the white/violet is listed as motronic control unit(txd) and the white/yellow is listed as motronic control unit(rxd). unfortunately, none of us seem to have figured out what to do with the white/yellow most say it isn't necessary. i say its there for a reason.

[flyboyx]

The running losses valve is AKA the 3/2 valve. It connects to the fuel pressure regulator under the driver's feet. (on an e36)

Check your injector connections, you may have a loose connection on Injector 1.

It doesn't matter if your MAF is bad or not, if you have that code, your car is in limp mode running off MAF backup maps. This is the biggest deal of all your codes.

Your fuel pressure should be 51psi minus manifold vacuum. 6-7psi is correct for a vehicle with a carb, maybe?

Oh and clear all the codes and see what comes back. Does the car run OK?

i have the factory e36 fpr installed under the floorboard. i will check the connection on that to see if it is installed correctly

the car was running fine until recently. as of late, it has been running poorly and stalling after a few seconds.

all of the info you posted here is really helpful matt. thank you for this. i cleared the fault codes but i have not run it yet. i will do so to see what i get.

oh, one other thing....it is a really tight squeeze between my maf and my hydro boost reservoir. i had my maf installed with the plug facing up instead of toward the driver side. i wonder if that could be an issue?

[MIKe30]

Thanks for the heads up about the diagnostic issue. It's important to me. Which 10 amp fused power did you decide to tap off of?

i had my maf installed with the plug facing up instead of toward the driver side. i wonder if that could be an issue?

Was also wondering about this, what is the proper way to install it... if it was up to me I'd have the plug facing down so it looks cleaner, but after looking at pics i moved it so plug is towards the motor. Any input?

[matt]

You don't need the white/yellow wire at all on an MS41. That's the wake-up/L-line that some older modules need. MS41 doesn't require it.

The direction the MAF plug points is important but not for this discussion. If you have a MAF code, it means one of a couple things. Your MAF could be bad. Your MAF wiring could be messed up. The wildcard is that the MS41 checks for the "plausability" of the signals coming from the TPS and the MAF against each other and if they don't seem to match, it will throw a code for one or the other based on its best guess. (In your case it would choose MAF)

[MIKe30]

You don't need the white/yellow wire at all on an MS41. That's the wake-up/L-line that some older modules need. MS41 doesn't require it.

The direction the MAF plug points is important but not for this discussion. If you have a MAF code, it means one of a couple things. Your MAF could be bad. Your MAF wiring could be messed up. The wildcard is that the MS41 checks for the "plausability" of the signals coming from the TPS and the MAF against each other and if they don't seem to match, it will throw a code for one or the other based on its best guess. (In your case it would choose MAF)

ok, and the direction is...?

[matt]

Thats complicated. Depends on your intake.

If you aren't using a full, unmodified e36 air box with stock filter, your MAF is not reading correctly.

[MIKe30]

Thats complicated. Depends on your intake.

If you aren't using a full, unmodified e36 air box with stock filter, your MAF is not reading correctly.

k, time for a new thread then.

[flyboyx]

Thanks for the heads up about the diagnostic issue. It's important to me. Which 10 amp fused power did you decide to tap off of?


Was also wondering about this, what is the proper way to install it... if it was up to me I'd have the plug facing down so it looks cleaner, but after looking at pics i moved it so plug is towards the motor. Any input?

i know that my thread has a lot of stuff inapplicable to this discussion but, i have added lots of circuits that wouldn't fit in the e30 box. power seats, heated seats, 2 ews circuits, fuel pump....well you get the idea. anyway, i just ran one more circuit in an auxiliary blade fuse box that i purchased on line. i ran it to switched power. hot in run/accy/start. i suppose you can use any circuit in your box that is close to that rating or less. pick something that isn't hot at all times.

[flyboyx]

ok, so...here's the deal. i reset my codes and the engine wouldn't start. it would crank over, but not fire. i started thinking that i somehow got my ews out of phase causing a no start. so, i pulled out the #1 spark plug and checked to see whether or not i have spark. the plug was whetted with fuel but i still have spark. so i changed my plugs(which i had been meaning to do anyway). the engine fired up like normal and sounded good. it ran for about 8 seconds and then quit on me again. i tried to start it again and the same thing. i ran the codes again with my peake. the air mass sensor and fuel injector number 1 code are now gone. i still have all the others and it is running the same. i checked the connection on the fuel regulator for the running losses code, it seems fine. i have another e36 fpr, so i might change it out to see if that is causing the code. at any rate, i wouldn't think these would be enough to make the engine not stay running. anyone have any better input?

[matt]

So... ALL you did was reset the codes and the car wouldn't start?

[MIKe30]

mine's running like shit too, but tonight I am going to check the tps then hopefully fix the diagnostic issue.

[flyboyx]

So... ALL you did was reset the codes and the car wouldn't start?

yes, that is crazy i know. it actually appeared to be flooded out. seems like all i did to get it to start again was change the plugs. really had me worried there for a bit. i just don't see how the codes i am getting would cause this problem. i have a fuel pressure gauge and am taking fuel pressure readings directly from the injector rail. unfortunately to do so, i have to disconnect that evaporative emissions hose that goes to the front of head because it is in the way of the valve stem on the front of the fuel rail. this air leak could be causing it to die,but when i disconnect the fuel pressure gauge, and replace the emissions hose, it still dies after running for a short time.

mike, i sent you a reply to the pm i had in my in box this evening. if that isn't clear enough, give me a call and i will try to explain it to you over the phone.