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E30 Build Thread

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48K views 265 replies 16 participants last post by  hornhospital 
#1 ·
This isn't going to be a build like my Hellrot, but nevertheless:

Picked this up for $475 the other day, looking to freshen it up for DD status and possibly sell it for a profit later.

84 318 coupe, 5 speed manual. 210k miles. [(ish) you know how E30s are]

Runs but dies after a second or two, cannot give it any throttle or it dies. Has some rust issues, and needs some other TLC.









Started tearing the interior to see what I have to work with.



Dafak?



PO said there was an alarm system that was removed and he "tied" these blue wires together to make it run. When I pulled them apart, sure enough it wouldn't even crank.

Yanked out a bunch of other wires too, then it would crank and not fire. So I hooked this relay back up and sure enough, she fired up again. I need to look at some wiring diagrams and clean this junk up. Did I mention the lower dash cover had about 6 different wood screws in odd places holding it in?





Started messing with different sensors, unplugged this one and it will idle for probably 30 seconds or so, maybe longer.



Rust in spare tire well, has some on the floor as well. I will probably take most of the interior out soon, I want black seats, door panels, and carpet. I need to secure the gas pedal on the floor as well, not sure how it's supposed to attach though.



Something was a little hungry...



Windows do not work either, but I guess they shouldn't when the switches aren't hook up, couldn't find the wires. Shouldn't be hard to find when the carpet is out. The driver's side door doesn't lock either. I can't do it with the key, or by pushing the lock cylinder down. I'm guessing something is simply seized up. Trunk and passenger door locks work.

I also had time to ohm the MAF, I'm uploading a video of it. Based on what I found I'm guessing it's shot as well which would be causing issues. While I'm at it I'm going to replace the spark plugs as well. Eventually I'll do the fuel filter and distributor cap/rotor/etc.

Comments/questions/help is encouraged!
 
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#3 ·
And you think an M42/44 is slow! Wait'll she runs enough to drive her. :rofl:






I'm pokin at ya.......nice find! I wish I could come up with a decent E30 coupe for short money like that. :thumbup:

I hope the rodents didn't get into the wiring, too. They ate the middle out of the harness on Eddie's 325e. Good thing we were swapping in the 325i harness.
 
#5 ·
And you think an M42/44 is slow! Wait'll she runs enough to drive her. :rofl:

I'm pokin at ya.......nice find! I wish I could come up with a decent E30 coupe for short money like that. :thumbup:

I hope the rodents didn't get into the wiring, too. They ate the middle out of the harness on Eddie's 325e. Good thing we were swapping in the 325i harness.
Haha, as long as it gets good mileage I'll be happy!

Did you watch my video? I'm new to using a multimeter and I want to make sure that the MAF is not under spec before buying one.

And for anyone with parts, my short list is:

Black interior parts, carpet, seats, panels
Sunroof handle
Passenger door handle
Radiator
Black window trim
Lowering springs
 
#4 ·
M10s, while pitiful in stock form, are good contenders for epic boost. All forged internals, can't go wrong. Matt, you know what you have to do....
 
#7 ·
watched teh vid, and that looks rather jumpy.

what does it read @ wot if it were propped open and you weren't using your hand (as to rule out an unsteady hand causing the fluctuation).

a power graphing meter would be a better tool to actually see the signal as the dme would see it, in a progressive 'line' of voltage.

all dvoms have a sampling rate, which is slower than a pgm. this is what makes them not such a great candidate for specing a potentiometer such as the afm, or tps, or such.

also, the sensor that you unplugged, was it a coolant temp sensor??




df
 
#11 ·
watched teh vid, and that looks rather jumpy.

what does it read @ wot if it were propped open and you weren't using your hand (as to rule out an unsteady hand causing the fluctuation).

a power graphing meter would be a better tool to actually see the signal as the dme would see it, in a progressive 'line' of voltage.

all dvoms have a sampling rate, which is slower than a pgm. this is what makes them not such a great candidate for specing a potentiometer such as the afm, or tps, or such.

also, the sensor that you unplugged, was it a coolant temp sensor??

df
Not sure what any of that means lol.
Does the maf move when I move the throttle with the engine off? Obviously I can't do it with the engine in since it would die.

Yes one of the coolant temp sensors. Just ordered one actually.

Sent from my ADR6400L using Bimmer App
 
#12 ·
If it's a flapper door type MAF the flap moves a shaft that changes the resistance in a potentiometer.
Digital multimeters don't take continuous measurements, they take a sample, analyze it, convert it to digital data that can be displayed on the LCD display. High end DMMs do this at a high rate and cheap DMMs do it at a slow rate. Your DMM may only be taking a measurement once every second or once every half second so you might not see a smooth linear transition from low to high. All that being said, assuming you're moving it continuously through it's range of motion, the radical swings in resistance make the MAF suspect.

The graphing DMM DF is referring to does the same as a DMM but it saves each sample and plots them in graphical format on the display. It's not unusual for a graphing DMM to be able to process 100K samples per second or more. High end graphing DMMs (which are really battery operated, handheld oscilloscopes) can take 20M samples per second, but it's pretty rare you find anything in a car that requires that kind of sampling bandwidth.

7K rpms equates to 117 revs per second which electronics wise is pretty damn slow.:)
 
#13 ·
I tried to make a continuous motion, I'm thinking it's definitely jumping all over the place. I don't have those fancy tools to check it another way lol.

Now I also disconnected the MAF (two connectors), and the intake air temp sensor with no change, still couldn't give it any throttle.

Another note, if I hold the pedal wide open and try to start it, it will start for a second and sound like it's missing before it dies.

Sent from my ADR6400L using Bimmer App
 
#14 ·
I tried to make a continuous motion, I'm thinking it's definitely jumping all over the place. I don't have those fancy tools to check it another way lol.

Now I also disconnected the MAF (two connectors), and the intake air temp sensor with no change, still couldn't give it any throttle.

Another note, if I hold the pedal wide open and try to start it, it will start for a second and sound like it's missing before it dies.

Sent from my ADR6400L using Bimmer App
try choking the engine... i know it sounds stupid. If you think you have a bad MAF but can't tell through any of the ordinary steps it's time to intervene. Basically if you choke out the air and it's still reading otherwise it could help the engine run. It could be over compensating at idle or under throttle because it thinks it's getting X(air) when it's actually getting Y. same thing as if the the intake boot or ICV hose was busted on our engines pretty much.
 
#17 ·
Car acts the same with or without the MAF hooked up, with or without the connectors hooked up as well.

Probably does have a bunch of leaks, it's been sitting 5 years.


With the Maf hooked up to the throttle body tube, and the wires plugged in or not plugged it, etc. I still can't give it any throttle. I'll go out and mess with it in a little bit, probably pull the plugs too.
 
#18 ·
Car acts the same with or without the MAF hooked up, with or without the connectors hooked up as well.

Probably does have a bunch of leaks, it's been sitting 5 years.

With the Maf hooked up to the throttle body tube, and the wires plugged in or not plugged it, etc. I still can't give it any throttle. I'll go out and mess with it in a little bit, probably pull the plugs too.
hows the fuel pressure? if it sat for 5 years, who knows maybe the filter or something got plugged or gummed up.
 
#25 · (Edited)
Matt, it may look to be in great shape, but is it worth a fan blade going through the rad to save $20?


EDIT:

An old brittle BMW plastic fan blade at that...
 
#36 ·
I'd say!

There isn't on the E36, dunno about the E30.

:lmao:
Blah, uploading video, I simply connected the fuel feed to a tester.

I know Ed's going to get a kick out of that lol. Drove the car just down the road and back and I can hear a strange noise, damn fan caught the shroud!

Oh well, have a shroud and expansion tank (old one was leaking I think) ready to go in. New fan on the way.
 
#37 ·
Uploading fuel pressure video now. It was quite strange, key on is around 30psi unless I turn the key on and off, then it goes all the way up to 80psi, wtf?


Also, I found a big vacuum line that goes to the throttle body elbow was disconnected.


Now it will idle sometimes high, sometimes low. Mind you this is with the airbox completely off, Maf disconnected, etc. Another note, I think it's flooding itself. I can start it and let it idle a few times but when it dies I sometimes cannot start it for a few minutes.

Could a big vacuum leak cause the FPR to add too much fuel?
 
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