Hard starting

[Jay 535i]

I've had my car about a year now, but I've known the car for four. As long as I've known the car, it has been a little reluctant to start. By that, I mean that you have to turn the key to 'start' for a good 2-3 seconds before the engine catches, which is a little longer than seems normal. Other than that, the engine sounds and feels normal when it does catch.

Lately I've noticed that on hot days with a warm engine it takes even longer -- maybe 4-5 whole seconds of cranking before it catches. This doesn't happen all the time, but sometimes.

Besides the extra time I have to hold the key down, everything seems perfectly normal. Is this something I should worry about, or is it a harmless quirk?

[SnakeyesTx]

I believe I brought this up yesterday with my 525 as well. Vapor lock was an idea tossed around, but I realized that it even happens with my motor cold (as in, not driven it all day then starting it for the first time sometimes).

As of yet, I still have no clue what's causing it.

[Alexlind123]

Almost exactly the same thing occurs with my car.

[Jeff N.]

Bruno has spoken. (http://www.bmwe34.net/e34main/trouble/535ihot_start.asp)
And there was great rejoycing.

[Alexlind123]

Bruno has spoken. (http://www.bmwe34.net/e34main/trouble/535ihot_start.asp)
And there was great rejoycing.

No, thats not the same thing. Its does it regardless of whether it is cold or hot.

[Qube]

Mine cranks in about three whurrrrs :) ...and I'm not far from you.

[Alexlind123]

Im beginning to wonder if my battery voltage is too low. Is there any way i can check the battery/alternator output myself?

[Jeff N.]

Lately I've noticed that on hot days with a warm engine it takes even longer -- maybe 4-5 whole seconds of cranking before it catches. This doesn't happen all the time, but sometimes.

Martin and I have discussed why we think the 535 takes a bit to catch when cranked. Our best guess is that it's DME related. It likely takes a revolution or two of engine for the CPS to determine the rotational angle of the engine and initiate the spark. Our guess is that the newer DMEs are more aggressive or better able to determine this and therefore initiate the spark faster.

At least, that's our story and we're stickin' to it.

[mamilapon]

Im beginning to wonder if my battery voltage is too low. Is there any way i can check the battery/alternator output myself?
There is a check valve integral to the fuel pump. Sometimes it just stops working, allowing fuel to drain back to the tank after shut down, hence the long cranking time. One cure is to purchase a separate valve. Check the procedure in the troubleshooting section of this site under M30 3.5 hot start job. Other than that it coud be a leaking injector.

[franan]

hey guys,i just have a big problem my problem is the car refused to turn off after removed the key from the ignition,how i turn it off just remove the #23 fuse the fuel one turn off guest what happen the light stay on on the dashboard the light when you turn the key position 2 before start the car battery light check engine light abs now i removed the negatif terminal from the battery help please i do have a feeling the ignition switch please help thanks.

[franan]

hi guys
i have a 1990 535i one owner with 98 k on it well when I turn it off refuse to turn after pull the key out.First i would like to know if the switch or computer problem okay how i turn off just remove the fuse#23 the fuel on turn off but the dashboard light stay on please help

[Alexlind123]

There is a check valve integral to the fuel pump. Sometimes it just stops working, allowing fuel to drain back to the tank after shut down, hence the long cranking time. One cure is to purchase a separate valve. Check the procedure in the troubleshooting section of this site under M30 3.5 hot start job. Other than that it coud be a leaking injector.

I thought it might be a leaking injector until i replaced my injectors.

[SnakeyesTx]

I see what you all are saying, but I have a 525.. with an M50 and it does this hot or cold. Possibly the same issue?

[mamilapon]

I see what you all are saying, but I have a 525.. with an M50 and it does this hot or cold. Possibly the same issue?
item 12 on realoem.com

[632 Regal]

wet your fingers with salt water and touch all the terminals?

Im beginning to wonder if my battery voltage is too low. Is there any way i can check the battery/alternator output myself?

[SnakeyesTx]

I like the idea of the checkvalve thing, and I followed the link, and BMA doesn't have it listed on their site by that part number. I did a manual search for it as well and came up blank. Anyone have a valid part number for it now?




Martin and I have discussed why we think the 535 takes a bit to catch when cranked. Our best guess is that it's DME related. It likely takes a revolution or two of engine for the CPS to determine the rotational angle of the engine and initiate the spark. Our guess is that the newer DMEs are more aggressive or better able to determine this and therefore initiate the spark faster.

At least, that's our story and we're stickin' to it.

[Jay 535i]

Thanks for all the answers.

It seems the problem is harmless. I'll continue to ignore it unless somebody has a good reason not to.