1984 carrera 3.2 wont start

[olopezus]

So I was in traffic a couple of weeks ago and car died and wouldn't start again.

I have no spark, no trigger. Car has no alarm.

I checked the dme relay and when I hit the ignition it works: I opened it and both relayes work, they actuate.

I checked resistance on the cylinder head sensor and its around 1, plus its the newer one with the 2 cables

Checked resistance in coil, although irrelevant as it gets no trigger and its around 60

I checked connection at computer and it has been opened previously, and since the cylinder head sensor is also newer I assume PO had this issue before

Any ideas before I have to start buying and switching parts to troubleshoot?

Tks

[rick-l]

Does the car smell like gas when you crank it? GAS and no spark = coil driver problem. You could also use a noid light or a stick to your ear to see if the injectors are clicking.

[vancouver86/911]

Mine did this when warm..turn the key, nothing...tapped the solenoid with the wooden end of a hammer while someone switched the ignition and it started immediately. Rebuilt the starter and no problems since.

[Hugh R]

I assume it cranks. A number of years ago, my 3.2 just died. After a lot of money being spent at TRE, it turned out is was an internally shorted fuel injector that was sending screwy signals back to the DME. TRE said they'd never seen that before. Hope that helps.

[ivangene]

does the fuel pump run? mine died - you can jump it with a wire from the battery to the fuse and listen - its easy check

[olopezus]

Hi all thanks, starter cranks, engine turns.

Would a fuel pump failure prevent spark from happening?

Gonna check the pump

[olopezus]

if its an injector i wonder if it will get spark if i disconect them and try one by one

[rick-l]

A shorted injector would not cause the spark to disappear.
A fuel pump failure would not prevent spark from happening.
The starter not working would not cause the spark to disappear on a running engine.

Does the idle air control vibrate to the touch with the key in the run position?
Do you smell fuel?

[wilstan]

Hi.......I had a problem long time ago with my distributor with over 250,000 mi. First sign of trouble was finding moisture inside the distributor with the cap off. This is the sign that your bearings on the rotor are starting to wear. Eventually, the car wouldn't fire at all until I finally rebuilt the distributor. Easy thing to check and eliminate if that is not the fault.

Wilstan

[TibetanT]

I am no expert, but this sounds to me like the reference or speed sensors may have failed. Especially since you said the car was running and then just died and would not start.

Test both sensors before you start buying parts.

Hope this helps.

[GeorgeK]

Went through this on my '84. Went from A-OK to no start. In my case the engine speed and reference sensors were bad. one died, the other had a dodgy connector. They can be measured for resistance at the connector.

[JTL]

My car has had this problem twice during my 15 years of ownership. The cause was a faulty reference sensor both times.

[olopezus]

Hi all, found a thread with the resistance to the sensots checked them out and DG Speed sensor was out of range.
This afternoon removed rear right wheel, shock absorber and both sensors, not difficult but very uncomfortable.

Will have to wait till next week to put it back together.

Thanks for the support

[DRACO A5OG]

Whatever you do not twist them in. They are liken to light bulb filaments, once twisted will snap the filament and she will not start, ask me how I know.

[rick-l]

BMW part # is cheaper, but do a search here to make sure this is right.

Reference Sensors

[DRACO A5OG]

Originally Posted by rick-l

BMW part # is cheaper, but do a search here to make sure this is right.

Reference Sensors

+1, it is 2" shorte, but no issues.

[olopezus]

thanks for the advice. hadnt thought about the twisting, will make sure i dont when i install back.

found a couple of threads with bmw part numbers, not feeling very confident to buy online, so gonna look local first so i can compare

[olopezus]

napa: $160

[gtc]

I have a couple of new BMW reference senders sitting on my shelf from my no-start a few months ago. I could get the part numbers and lengths for you if it would help. I think they were from an old 635csi.

[rick-l]

$160 for two?

If you plug that number (12 14 1 708 618) in the little box at the top of the page they are $75 here.