Starts, stumbles, and dies...

[Gnarles]

Yeah you need the obd1 coolant temp sensor for the dme (blue top sensor) and the m20 temp sensor for the cluster (brown top). Unscrew the tb heater fitting from the head and delete the tb heater system. I filed down the m20 sensor and rethreaded it to screw into the now unused hole in the head. This has been covered numerous times.

[r4esh]

Wow in all of my reading and research I can't believe I didn't know this about the temperature gauge. too late to drill/tap the head... I will now try and find another method. Gnarles you are saying that I HAVE to use the obd1 engine temperature sensor? I have not read about this anywhere.. can someone verify? OR will the obd2 engine temperature sensor work fine for the DME if I have the turner adapter?

I don't want to have to drain ALL the coolant out of my system to thread the coolant temperature sender for the gauge - as in thread into where the throttle coolant lines go, plus the I'd have to somehow block off the return line for the throttle coolant as well (not sure if that makes sense). What would be an alternative? Someone suggested an "inline" sensor? Can someone link me? This would still require draining the system huh? Anything I can do in the meantime?

There are 4 pins on the engine temperature sensor. The ETM says to test ohms, but doesn't specify which pins or anything to test. I went through all of them and after several combination only got 1 reading which was what the ETM said it should be.

UPDATE: SO I pulled the intake. First off, if someone has a map-out of exactly how the vacuum lines should run, it be nice for me to double check mine. Second... my "intake temperature sensor" was not plugged in.. instead the harness adapter was plugged in to 'electric valve' on the vacuum lines. Is that electric valve even used for this swap? Whats it for?
I'm talking about part number 7 in THIS diagram.

Would that be causing the issues my car was having?

[r4esh]

Back to this... Heres the deal:
SYNOPSIS: e30 1989 325is with 96 328is and zf tranny swap. OBD1 conversion (red label ecu, harness, intake, MAF, chip, etc, etc.).

Swap went well. Used ALL OBD1 BRAND NEW SENSORS (crank, knocks, etc). Got the car running, but it wouldn't hold its own idle and was pretty rough. Also If I diconnected the MAF, then the car WOULD hold its own idle.

Pulled intake and started going over ETM tests for every sensor I could, even if new, and everything checked out OK except the Cam sensor. I thought I was on to something soo.....

Swapped it out with a new cam sensor. Threw the intake back on and went to start the car, but now all I get is cranking. No start.... The car cranks hard, but no start. I can hear the fuel pump going + didn't mess with any of the fuel lines or anything. I know the first thing someone is going to say is test for spark... but the car WAS "running". All I did was swap the cam sensor with a new one + quadruple checked that everything was were it was supposed to be.

At this point, I've got new 3.5'' MAF, Knock sensors, cam sensor, crank sensor, iridium plugs. This car is giving me such a headache I can't believe... once again I'll probably have to pull the intake (20-30 mins each time) and check AGAIN whats going on down below. SO....

ANYONE HAVE ANY IDEAS / THINGS I CAN quintuplet CHECK WHILE I'M UNDER THERE?

[MattM]

did you unplug the battery to reset the ECU when you did the cam sensor swap? unplug the battery for at least an hour to reset the computer so it will be back to limp home mode...

yes there is an inline sensor you can get, that goes inline in the throttle body heating hoses. i have a spare turnermotorsports one i could sell you if you wanted(pm me)

[r4esh]

So this wouldn't account to why it isn't starting NOW. But on the m52 car there is a fuel pressure regulator located underneath the drivers seat bottom of the car rather than on the fuel rail like the m50 and m20 motors... I'm still using the m52 fuel rail just modified... and I didn't keep the m20's fuel pressure regulator. I THOUGHT it was in the rear on my car.. but maybe I don't have a fuel pressure regulator hooked up??? Would that explain why it was running, just running 'rough'???

[sushipower]

Yes, you do need a fuel pressure regulator. But if your car was running before. it's probably something else. Are you sure your air intake sensor is hooked up right? Double check, it's the same plug for the oil or water temp sensor. See if someone in your area has a modic scanner. GL

[r4esh]

I triple checked the air intake temperature sensor. It is hooked up right. and I confirmed I am not running ANY fuel pressure regulator currently (I think this is the culprit). It would make sense why it was running, but not running well + it would explain why as I held my foot down and reved to say 3.5k rpm, even with my foot down the rev would start to drop all the way until it died again. now I'm stuck though... I either have to find a obd1 fuel rail with a built in fuel pressure regulator OR buy the one for the m52 and place it inline somewhere. BUT my question if I do that - Where / HOW do I pull vacuum to it? It needs vacuum right? Where from?

[matt]

Yes, you do need a fuel pressure regulator. But if your car was running before. it's probably something else. Are you sure your air intake sensor is hooked up right? Double check, it's the same plug for the oil or water temp sensor. See if someone in your area has a modic scanner. GL

His car wasn't running before. It's never run right as far as I can tell.

You need the OBD1 fuel rail with integrated FPR. I can send you one if you need it. There is a vacuum nipple on the bottom of the manifold to connect to the FPR.

PLEASE talk to me (PM or email) and let me help you figure this stuff out before you start replacing parts. No FPR = No chance to run right.

[sushipower]

Using a long nose pliers, squeeze the fuel line, this will create pressure. Then have one of your buddy crank the motor.

[r4esh]

UPDATE: I swapped my 'engine temperature connector' with the 'guage temperature' - they must have been backwards, because it started right up. The timing is resolved! Car holds its own idle. SOO... when I replaced the CAM sensor that must have done the trick!!! Its VERY good news, but thanks to all of this I did determine I don't have a FPR hooked up... sooo once I resolve that I should be good to go. <- just wanted to post the solution for furture readers searching for the same problem / issues.

Thanks R3Vers!!!

[matt]

Either that, or swapping them made it wrong, but it's wrong in the right way to make the no-FPR problem better.

You need to make sure you have them hooked up correctly when you put the FPR fuel rail on there.

[r4esh]

Again for a future reader who stumbles upon this thread looking answers to similar issues they may be having....

Installed the new CAM sensor and installed the missing Fuel Pressure Regulator (FPR) and voila!!! The car is running great! AND Fast! I'm very pleased! Thanks for your help again everyone!

[MattM]

UPDATE: I swapped my 'engine temperature connector' with the 'guage temperature'

so i guess that tripple checking all sensors and connections didnt happen earlier ;)

glad you got it figured out :p

also back to earlier question, i am not running a check valve at all right now, and ive been daily driving my car for 3 months without issue... if you have one it doesnt hurt to install it.

[matt]

The check valve basically lets you keep one brake application in reserve if you have a motor failure. Not having one is not a huge deal.