1992 500Sl Long Start? - PeachParts Mercedes-Benz Forum

Philip Justice · #1 08-01-2008, 05:41 PM

Phil Here, I brought my SL. in for it's 60,000 mi. Service ahead of time to correct a condition in which I thought was not normal for a Mercedes. It took 3 to 4 seconds of Cranking after i turned the ignition key for the engine to fire up on a cold start. The Sl. was starting a little faster after service but now at a cold start and sitting for a few days, The SL. has been taking 7-8 seconds to fire up and than 1 second of small "flutter before it clears up?

This drives me crazy! I want my SL. Fire up fast! Once the Car does start it runs out fantastic, Can any one point me in the right direction to what might be the area of the problem. If I can get close By your expertise, I can than direct that to my Mechanic for repair or adjustment.

The 60,000 extensive service included compete tune-up w/ new Bosch plugs.
My service shop is not a official MB shop but I think he has a competent knowledge of the SL., All they service are MB's Audie's and BMW's.

Maybe some of you guys with early 90's 500 Sl's have had the same problem and can help me out? My Brothers 1997 Ford "beater" Taurus starts within a half a second of "Cranking" My SL. does not. Thanks in advance.

1992 Sweet 500SL Phil Justice
61K

kennedy · #2 08-01-2008, 08:03 PM

try this, turn key on but don`t crank engine, just power up the electric fuel pump or pumps, once pumps turn off do it again to built up fuel presure, than try starting and see what happens.

Philip Justice · #3 08-01-2008, 08:47 PM

Kennedy, Phil Here. Will try your suggestion in the AM. That will be a Cold Start For me. I will post the results. Any other areas of concern will be much appreciated, Thanks,

1992 Sweet 500Sl Phil Justice

deanyel · #4 08-01-2008, 09:34 PM

Without seeing the fault codes my guess(es) would be fuel pressure regulator, injector leak down or caps and rotors.

Philip Justice · #5 08-02-2008, 10:47 AM

Phil Here, This morning I "Cold " started my SL. using Kennedy's Key system, the SL. took 3-4 seconds to fire. A lot better than 7-8. But of course I don't think I would have to go through that every day. Now for Deanyel's suggestions, Do you think the Fuel regulator is not preforming as it should? I only have 61K 0n my Sweet SL. or is it that my Mech. did not read the Codes at time of Service to detect a fuel delivery problem?

Any other Feed-back would be appreciated and I will take remedy back to MB Shop.

I choose to own and drive a almost perfect 500Sl. I want to look and preform like a Mercedes should! If it dose not start in a heart beat I get depressed. Thanks

1992 Sweet 500Sl Phil Justice

deanyel · #6 08-02-2008, 11:52 AM

Do you know that the mechanic checked the fault codes at the 60k service? Did they replace the caps and rotors? If not I would start with an inspection of the caps and rotors - there's two sets, one on each bank of cylinders. If they look OK and you're not getting any fault codes on socket 8 (DI) you can focus on fuel issues.

Philip Justice · #7 08-02-2008, 01:06 PM

deanyel, Phil Here. I will take the Sweet SL. to my MB.Mech. Monday and give him all the info that I recieved from this Forum and see what he has to say. I am looking at my Bill for the 60K Service [300.00] It includes, read all Codes for "Extended Crank" Oil Change, Tune -Up w/ New Bosch plugs, etc,etc. Nowhere does it say anything about replaceing the Caps and Rotors.
Thanks.

1992 Sweet 500Sl Phil Justice

deanyel · #8 08-02-2008, 01:18 PM

Distributor caps and rotors would be around $200 in parts alone. If original they would be due for replacement. If you don't the history it would be a good idea to at least inspect them.

#9 08-05-2008, 08:57 AM

When you initially turn on the key, it pressurizes the fuel system. You should normally pause and allow this to happen.

pollockd17 · #10 08-10-2008, 08:30 PM

How's the fuel filter, I found out after a problem that the fuel system likes a nice unrestricted fuel flow. The mech. fuel injection system needs 78 lbs. pressure, says the book and it's a cheap experiment that might be the answer

Good Luck...

moakesr · #11 08-11-2008, 02:25 AM

Just replaced caps and rotors on my 1991 500SL, definitely starts much faster now, doesn't seem to need to turn over very much before it fires.

Always seemed to need a couple of revolutions before it started with the old caps and rotors.

Quote:

Originally Posted by deanyel

Distributor caps and rotors would be around $200 in parts alone. If original they would be due for replacement. If you don't the history it would be a good idea to at least inspect them.

johnathan1 · #12 08-11-2008, 02:28 AM

Cold start injector, perhaps? It may need to be cleaned or replaced...at least that's usually what the problem is on most cars that have this problem...

Philip Justice · #13 08-11-2008, 01:52 PM

Phil Here. Regarding my "Long Cold Start". At my 60,00 mi. Service, My MB Mech. did not replace anything that did not show " Faulty by the Codes. He does try to save me $$$. Today ,at my request they will replace my Caps and Rotors,Fuel filters and check out the fuel pressure. I think those Items were border-line at 60,000 mi.at best. I will buy the parts and he will charge me labor. He did the same for me regarding a Head Lamp Switch I bought from a member at this Forum. 25.00 for the switch, 45.00 labor.

I will report back on how my Sweet SL. responds to the New stuff added.
Thanks Again for all your help.

PS. The Head Lamp switch I purchased came from the member called "RONCALLO" Please support our friends at this forum. Ron has parts for your 90"s SL. and he is also on Ebay.

1992 Sweet 500SL Phil Justice