Cranking the engine with ignition and fuel pump disabled.
11-10-2010, 12:37 PM
#1
Racer
Thread Starter
Cranking the engine with ignition and fuel pump disabled.
For winter storage, I don't believe in starting the engine outright but prefer to just crank for a minute to splash the oil around inside the engine without ignition or fuel every few weeks.
On my old 911, I just unplug the Bosch CDI module and remove the pump relay.
On the 993, I assume that removing the DME relay will do the same?
Will removing the DME relay disable ignition AND fuel pump?
Thx.
On my old 911, I just unplug the Bosch CDI module and remove the pump relay.
On the 993, I assume that removing the DME relay will do the same?
Will removing the DME relay disable ignition AND fuel pump?
Thx.
11-10-2010, 12:51 PM
#2
Race Director
To be honest, this is a waste of time and battery power.
If you really want to do this, the DME will disable the fuel, but not the ignition.
That said, if theres no fuel, the ignition ain't gonna do much of anything.
If you really want to do this, the DME will disable the fuel, but not the ignition.
That said, if theres no fuel, the ignition ain't gonna do much of anything.
11-10-2010, 01:06 PM
#5
Rennlist Member
Oliver is correct...
Unless you are going to fire it and bring it up to temp any moisture accumulated from sitting will still be there.
That said, it won't hurt anything to do this. As already said, remove DME.
Unless you are going to fire it and bring it up to temp any moisture accumulated from sitting will still be there.
That said, it won't hurt anything to do this. As already said, remove DME.
Last edited by MarkD; 11-10-2010 at 02:41 PM.
11-10-2010, 01:08 PM
#6
Nordschleife Master
Wait for a clear day, & take it for a drive.
I love it when the weather clears, & I can take the car out & blast down the road! I try to drive my C4S at least every 3 weeks.
I love it when the weather clears, & I can take the car out & blast down the road! I try to drive my C4S at least every 3 weeks.
11-10-2010, 01:09 PM
#7
Race Director
Trending Topics
11-10-2010, 01:19 PM
#8
Racer
Thread Starter
No winter driving here; snow and salt. 
It is my understanding that the DME relay also disables ignition. Is that wrong?
Are you saying that it only disables the fuel pump?
It is my understanding that the DME relay also disables ignition. Is that wrong?
Are you saying that it only disables the fuel pump?
11-11-2010, 02:29 AM
#10
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
My understanding is the DME removal will turn both the fuel and ignition off.
I do this after filling the oil during oil-changes to make sure the oil has filled all the passages in the engine. I do the change, new filters, fill 8 liters, pull DME, crank tlll I see oil pressure, replace DME, start, run a bit, shut off engine, top up to 10 liters.
If the car sits more than two weeks, pull DME, crank till oil pressure, put back DME, start.
We can argue if this helps or not, but I could not see what harm this can do other then a bit more wear on the starter, and perhaps a drain cycle on the battery. Makes me feel better..
Cheers,
Mike
I do this after filling the oil during oil-changes to make sure the oil has filled all the passages in the engine. I do the change, new filters, fill 8 liters, pull DME, crank tlll I see oil pressure, replace DME, start, run a bit, shut off engine, top up to 10 liters.
If the car sits more than two weeks, pull DME, crank till oil pressure, put back DME, start.
We can argue if this helps or not, but I could not see what harm this can do other then a bit more wear on the starter, and perhaps a drain cycle on the battery. Makes me feel better..
Cheers,
Mike
11-11-2010, 09:52 AM
#11
button queen
Gunter,
I did this after last winter for exactly the same reason you will. It's to get oil moving, not to try and burn off water--you don't crank for long enough to do that. In fact I got the tip off Rennlist here from someone.
It worked like a charm. Engine turned over and did not start. DME replaced and it started right up.
BTW I also got the following procedure recommendation after you reinsert the DME:
1. Ignition in the ON position (full dash lights), but engine not running, for 2 minutes.
2. Engine started and idle for 3 minutes.
3. Go drive aggressively (or your normal style) to "retrain" the system.
Apparently this avoids some possible rough engine operation while the DME and ECU are learning.
I did this after last winter for exactly the same reason you will. It's to get oil moving, not to try and burn off water--you don't crank for long enough to do that. In fact I got the tip off Rennlist here from someone.
It worked like a charm. Engine turned over and did not start. DME replaced and it started right up.
BTW I also got the following procedure recommendation after you reinsert the DME:
1. Ignition in the ON position (full dash lights), but engine not running, for 2 minutes.
2. Engine started and idle for 3 minutes.
3. Go drive aggressively (or your normal style) to "retrain" the system.
Apparently this avoids some possible rough engine operation while the DME and ECU are learning.
11-11-2010, 10:15 AM
#12
Three Wheelin'
I've only done this (remove the DME relay) and cranked the engine after the car has been sitting for AT LEAST a month (in the cold).
Each time -- I've only cranked the engine 3 times - and each time for no more than 2 seconds (count them!). When I see the oil pressure past the 3 (and usually by the last crank) bordering on 5 - then I know that I've reasonably "pre-lubed" the engine BEFORE I start it / apply a 'load' to it.
Then I go out and drive the car (at least 100 miles).
Do NOT 'over crank' !!! -- the negative battery cable gets REALLY FRIGGIN HOT!!!
Obviously do NOT do this with a 'weak' battery!
Gerry
Each time -- I've only cranked the engine 3 times - and each time for no more than 2 seconds (count them!). When I see the oil pressure past the 3 (and usually by the last crank) bordering on 5 - then I know that I've reasonably "pre-lubed" the engine BEFORE I start it / apply a 'load' to it.
Then I go out and drive the car (at least 100 miles).
Do NOT 'over crank' !!! -- the negative battery cable gets REALLY FRIGGIN HOT!!!
Obviously do NOT do this with a 'weak' battery!
Gerry
11-11-2010, 10:50 AM
#13
Racer
Thread Starter
My understanding is the DME removal will turn both the fuel and ignition off.
I do this after filling the oil during oil-changes to make sure the oil has filled all the passages in the engine. I do the change, new filters, fill 8 liters, pull DME, crank tlll I see oil pressure, replace DME, start, run a bit, shut off engine, top up to 10 liters.
If the car sits more than two weeks, pull DME, crank till oil pressure, put back DME, start.
We can argue if this helps or not, but I could not see what harm this can do other then a bit more wear on the starter, and perhaps a drain cycle on the battery. Makes me feel better..
Cheers,
Mike
I do this after filling the oil during oil-changes to make sure the oil has filled all the passages in the engine. I do the change, new filters, fill 8 liters, pull DME, crank tlll I see oil pressure, replace DME, start, run a bit, shut off engine, top up to 10 liters.
If the car sits more than two weeks, pull DME, crank till oil pressure, put back DME, start.
We can argue if this helps or not, but I could not see what harm this can do other then a bit more wear on the starter, and perhaps a drain cycle on the battery. Makes me feel better..
Cheers,
Mike
The only reason I do it is that there are lots of parts inside the engine that can rust. Some people don't understand that there are areas with winter conditions preventing a drive to get the engine really hot and letting it idle until hot is NOT good.
It only takes a few seconds of cranking to build up pressure. Winter storage is for about 6 months, full tank with Stabil and Techron run through the system.
So, with DME relay removed, the ECU is disabled and there is no spark.
11-11-2010, 10:58 AM
#14
Drifting
11-11-2010, 12:27 PM
#15
Rennlist Member
Pull a valve cover and have someone crank. Note the volume of oil that has sprayed out, instantly. And if you've got your face in there, it will probably take a weeks worth of washing to finally get it all off.