e34 535i no start

[hamzalam]

Hi guys,

My 1990 535i is not starting up after an engine rebuild. At first it didn't even crank but then I realized that the engine wasn't grounded and I plugged the broken strap back in. With the help of some starter fluid it fired up, but it kept on dying. It ran pretty erratically. I got it running for about a minute max. Then it stopped starting up. I first thought it was a no fuel issue. The relay was working and I checked the voltage at the electrical connector for the fuel pump. It got good voltage but at the fuel pump there was nothing.
Same problem:
https://www.bimmerforums.com/forum/s...nector-Failure


So I replaced the fuel sender assembly, but the car still didn't start.

There is pressure in the fuel lines and the pump runs, but when I crank the engine and touch a fuel injector with a screwdriver it doesn't seem to tick.

Then I checked if the spark plugs were sparking, and they weren't. I also saw that they were completely carbon fouled. (but they must have been sparking before because the car was running)

When I opened up the distributor cap there is a little bit of oil inside. I am pretty sure that this is due to the cover behind the rotor being cracked and oil got in there when the car was running

I also checked the crankshaft position sensor, which is in spec at 540 ohms. If it has the correct resistance does that mean that it works?



Any help would be greatly appreciated, I really want this thing on the road.

[bmwdirtracer]

I'm a bit confused by what you've written. I'm not sure how replacing the fuel sender (pump?) assembly fixed the fact that you had no power at the pump plug?

I'd also note that because the pump runs, and because you have "pressure" in the fuel lines doesn't mean that you have correct fuel pressure at the fuel rail.

However, none of that really matters, if you have no spark, and no injector pulse. Let's go ahead and deal with the oil in the distributor cap: that black cover inside has nothing to do with it: There is a camshaft seal behind that cover; that's what's leaking. If you rebuilt the engine, you should have replaced that seal. And, I've got to ask: how do you rebuild an engine, and leave "completely carbon-fouled" sparkplugs in it?

But....that's not why you have no spark and no injector pulse. THAT is because the engine computer is not trying to start the car.

Because the crankshaft sensor has correct resistance doesn't necessarily mean it's good, but since you indicate the engine was recently running, that's likely not your problem.

Is there power at the coil, when the key is in the on position?

Here's a link to your wiring diagrams:

http://wedophones.com/Manuals/BMW/19...g%20Manual.pdf

[hamzalam]

There is no power at the coil. The spark plugs were fine when I put them in but they became fouled in the short time the car was running.

[bmwdirtracer]

This is crucially important: Please go out and confirm, using a multimeter or test light:

Are you saying that the green wire at the positive side of the coil does NOT have 12 volts when the ignition is in the "ON" position ???

Do NOT assume, this is crucial.

[hamzalam]

I just double checked... the positive side reads 0 volts when the car is at the on position

[bmwdirtracer]

Please look at the wiring diagrams, page 85. Either your ignition switch is bad, or the big round X-20 connector underhood is not plugged in, or you've got a cut wire. Best guess: the round X-20 connector isn't properly rotated into place.

Do not bother checking anything else until the green wire at the coil is hot.

EDIT: See page 290 of the wiring diagrams, to view the X20 connector. The picture is terrible, but it will show you the location, right near the left shock tower.

[hamzalam]

I made sure the x20 connector was in but still no power to the coil.

[hamzalam]

the multimeter still shows no voltage... but just now i held a screwdriver by the top plug that delivers power to the spark plugs and it sparked

[bmwdirtracer]

I really don't know what you mean by "the top plug that delivers power to the spark plug", and I don't know what you mean by saying you held a screwdriver to that, and it sparked. Was the key being turned? I mean, a coil's spark is fifty thousand volts, and will give you a helluva jolt.

But if there's no power at the coil, who knows, maybe you just had a polyester sweater on, and saw static?

If there is truly no power at the coil, either the X20 is not connected, or your ignition switch is bad. Personally, I don't think this is the case. Do you have power at the jump start terminal underhood?

[hamzalam]

I touched a screwdriver to the main lead that delivers the power to the distributor. I definitely got a jolt when the key was turned on... (which means there is power at the coil?) But the working multimeter shows nothing

I do have power at the jump start terminal.

[ross1]

So, you got a jolt off the coil wire(the fat lead from coil to the dizzy) but no 12V at the + terminal? Impossible. If you got a good jolt but no spark at the plugs start looking at the dist rotor and cap. Also check with the cap off if the rotor is even turning, could have lost the timing chain.

[bmwdirtracer]

Yep. Impossible. One of your pieces of information is wrong, hamzalam.

[hamzalam]

I confirmed that I have power to the coil. The rotor spins and I swapped the dizzy cap with another one I had but still no difference.

I was testing my cps and its resistance is fine but when I check the shielding, Pins 1 and 3, and pins 2 and 3, both read about 180k Ohms. It should be 100k.

http://www.bimmerboard.com/forums/posts/645078
(The link shows cps testing instructions from the Bentley manual)

[hamzalam]

any ideas?

[bmwdirtracer]

Sorry, no, I have no ideas because I really have no idea what information is correct, and what's not.

I've already done research (above) on your wiring diagrams, based on grossly incorrect information. I've got no idea if you have spark, correct fuel pressure, or injector pulse, or whether your broken engine ground was ever properly fixed, or whether your computer's grounded, what's hooked up, and what's not.

AND, I'm pretty sure your multimeter is crap. Do you know that you can't ever test a powered circuit with your multimeter set on Ohms, or you kill the meter?

I'm sorry, I believe that you need a BMW pro with known good tools to lay hands on your car for a while, and do some testing. I have no valid information, so no valid answers for you.