New e30 driver with an annoying no-start

[BKCowGod]

Hi all -

New to e30 ownership, but not new to BMW's. First car was a 1970 Ireland Engineering modified 2002, then I moved on to e28's for a while. Now my DD is an Audi UrS4. It's mid-timing belt and my truck decided it didn't want brakes, my brother had his iS sitting around... So now it's my problem.

He bought it as a salvage title, running perfectly. Salvaged because the paint sucks and the bumper fell off. Someone loved it, because it has m42club and e30 stickers on the windows, but it's definitely a bit of a beater now.

Anyway, the current problem. Just before passing it to me, my bro rear-ended someone at 5mph. No visible damage, but when the car hits a speed bump too hard it sometimes shuts down. Until recently, either letting it sit or popping the battery off would get me going again.

Two days ago, left it in the parking garage and when I came back in the evening it would crank like crazy but wouldn't start. I had no tools with me, so I called AAA and was gonna get towed home. We went to roll it down the ramp and out of the garage and just for fun I decided to pop the clutch on the way down and it started right up.

I suspect somewhere on the car there's a fuel pump cutoff (inertia switch style). What I need to know is where it is and how to bypass/repair it. Thoughts, assistance, all appreciated.

Oh, and hi! I promise I will be more contributory in the future.

[bmwman91]

Welcome!

There is no inertia switch for the fuel pump, actually. The only ones that I know of are for the airbag and the door lock controller.

When it is misbehaving, measure the voltage at the front upper power block on the passenger side of the firewall (you'll see the huge black wire go to one block, and the smaller black one go to a separate block above it). Check for 12V on that upper block where the smaller black wire goes. If it isn't reading 12V, the fusible link in the trunk is busted. It is a relatively common issue to have that corrode & make intermittent contact (the entire fuel system is on a separate line from the rest of the car).

[BKCowGod]

Awesome, I was planning on checking the fusible link tomorrow. I was just pissed that it ran with a bump start but wouldn't catch, even though the starter was cranking VERY healthily.

[DesktopDave]

That's a great suggestion...shutting down on speed bumps, haven't heard that one before!

[BKCowGod]

That's a great suggestion...shutting down on speed bumps, haven't heard that one before!

I've had worse - I had a '70 Jeep pickup that would lock the throttle cable at WOT if you hit a bump too hard. 401ci V8 with 4 wheel drums and a lot of weight. Not fun.

[bmwman91]

Let us know what you find. I suggested the fusible link because I had that issue, and it took me 5 years to figure it out lol. I checked & replaced damn near everything else in the fuel & ignition system, never thinking to check the fusible link. I had to splice a replacement in shortly after getting the car when I made an "oops" with a box wrench...apparently I did a lousy job of crimping the butt splices the first time through! I didn't think to check it for all of those years because I knew that I had "fixed" it lol.

[BKCowGod]

I'm feeling lazy. Will check it eventually.

Interesting car, though - I was checking it out today and someone loved this vehicle at one point. The engine compartment is spotless and it has H&R springs, and I really do suspect it has a swapped rear end. K&N filter, a/c delete, no sunroof, ellipsoids... And trashed body. It's all over the place.

Crappy camera phone pic ftw

[BKCowGod]

Bam.

Held it together with a bobby pin and it runs fine (don't worry, I'm gonna do something more permanent)
can you say best photo ever?

[deansweet]

that is the best photo evar?!
Good to hear it got sorted out.