928S cold start: It doesn't :-)
Thread Starter
Rennlist Member
Joined: Mar 2003
Posts: 1,195
Likes: 78
From: Washington DC
928S cold start: It doesn't :-)
So we had our first really cold night, 10F. Went out this morning, started up the 86.5 928S, turned over and started on the first crank. Waited a minute to let it stabilize, put it in R, drove it up the hill backwards, let off on the gas, stalled.
And would not restart. Could smell gas so the car is flooded. This has happened a few times before, normally I can pump the throttle and get it going, but it's out. So I rolled it back down, put the battery on the charger, and took the 944S for the day's duties.
I'm assuming it's the idle air bypass valve, correct? And is the best way to de-flood the engine to pull the fuel pump relay or can I just pull the fuse?
Might be time to shut it down for the winter and pull out the fuse box for a long-overdue rebuild....
And would not restart. Could smell gas so the car is flooded. This has happened a few times before, normally I can pump the throttle and get it going, but it's out. So I rolled it back down, put the battery on the charger, and took the 944S for the day's duties.
I'm assuming it's the idle air bypass valve, correct? And is the best way to de-flood the engine to pull the fuel pump relay or can I just pull the fuse?
Might be time to shut it down for the winter and pull out the fuse box for a long-overdue rebuild....
Rennlist Member
Joined: Jul 2006
Posts: 5,422
Likes: 627
From: Bloomfield, MI
I will usually wait until the temp gauge gets out of the White, especially when it's cold outside, as you know, the engine gets more (richer) fuel when cold per the programing, this warm-up enrichment map stays fairly rich until engine temp goes above 100deg F.
Depending on the Temp it could take several min's. to start getting back to a desired AFR of 14.7 at idle, else AFR is in the 13's or even high 12's (Rich).
This is why its not a good idea to start and move a cold car and shut it off, unless its already up to temp, as this will tend to never let the engine run clean and thus foul the plugs. This happens a lot at Body shops and service centers as they need to move cars around
As for the holding the peddle to the floor, (you need to engage the Kick-down switch), and I'm not sure when the Kick-Down Relay was installed (what MY) that has that function, nor what was done for a manual trans ???
Anyway pumping the peddle doesn't do anything on a Fuel Injection engine, just hold it WOT and crank, pull the fuse as said
Dave K
Depending on the Temp it could take several min's. to start getting back to a desired AFR of 14.7 at idle, else AFR is in the 13's or even high 12's (Rich).
This is why its not a good idea to start and move a cold car and shut it off, unless its already up to temp, as this will tend to never let the engine run clean and thus foul the plugs. This happens a lot at Body shops and service centers as they need to move cars around
As for the holding the peddle to the floor, (you need to engage the Kick-down switch), and I'm not sure when the Kick-Down Relay was installed (what MY) that has that function, nor what was done for a manual trans ???
Anyway pumping the peddle doesn't do anything on a Fuel Injection engine, just hold it WOT and crank, pull the fuse as said
Dave K
Thread Starter
Rennlist Member
Joined: Mar 2003
Posts: 1,195
Likes: 78
From: Washington DC
Well my kick down switch doesn't (I really need to adjust the pedal) but yeah, it stalled out after I was in R, went up hill, and took foot off gas to stop.
Sometimes I can catch the engine with partial throttle, then get the motor running then revved up to clear out the cylinders (that's what I meant, not the old pump the throttle to have the enrichment pumps put more gas into the carbs. There ain't no carbs :-) but I'll try it tomorrow, get it running, then shut it down for the winter and do some maintenance.
Sometimes I can catch the engine with partial throttle, then get the motor running then revved up to clear out the cylinders (that's what I meant, not the old pump the throttle to have the enrichment pumps put more gas into the carbs. There ain't no carbs :-) but I'll try it tomorrow, get it running, then shut it down for the winter and do some maintenance.
You can call me Otis
Rennlist Member
Rennlist Member
Joined: Feb 2013
Posts: 6,661
Likes: 10
From: Terre Haute, Indiana
Normally mine starts right off with the turn of the key, but it's been hovering at o°F lately.
I have a newish AGM battery, and it takes a lot of cranking till it fires up. It will eventually start if I hold the go pedal down while cranking, then I have to hold it at about 1100 rpm for a bit so it won't die at idle.
I have a newish AGM battery, and it takes a lot of cranking till it fires up. It will eventually start if I hold the go pedal down while cranking, then I have to hold it at about 1100 rpm for a bit so it won't die at idle.
Trending Topics
Thread Starter
Rennlist Member
Joined: Mar 2003
Posts: 1,195
Likes: 78
From: Washington DC
Same here, mine always starts on the first crank. Part of the reason I don't want to crank endlessly; it's tough on the motor and starter. Big big motor.
It's on charge tonight, I'll take a look at it tomorrow or Saturday.
It's on charge tonight, I'll take a look at it tomorrow or Saturday.
Rennlist Stories
The Best Porsche Posts for Porsche Enthusiasts
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look
Verdad Gallardo
10 Porsche Colors That Have More Personality Than Most People
Verdad Gallardo
Guntherwerks' Final Speedster Creation Is the Ultimate Porsche Restomod
Verdad Gallardo
10 Reasons I Hate Going to the Porsche Dealership (& the 1 Reason I Stay)
Joe Kucinski
Porsche Shakes Up The Nürburgring Lap Record Table Once Again
Verdad Gallardo
6 Ways the Porsche 911 GT3 S/C Redefines Performance
Joe Kucinski
10 Wildest Homologation Specials Porsche Ever Sold
Verdad Gallardo
Super Rare RUF BTR III Comes Out of Hibernation, Looking For a New Home
Verdad Gallardo
10 Porsche Opinions That Can Start a Fight
Joe Kucinski
Thread Starter
Rennlist Member
Joined: Mar 2003
Posts: 1,195
Likes: 78
From: Washington DC
Update: Car started on first crank today, ran rough for a moment, then stabilized out. Let it run for 5m to recharge battery and warm up a bit, seems ok so shut down.
I'll start taking some things apart once it gets above freezing, too cold to work much right now. Thanks for the replies, one of the tasks will be to re-adjust the pedal so the tripdown switch activates like it should.
I'll start taking some things apart once it gets above freezing, too cold to work much right now. Thanks for the replies, one of the tasks will be to re-adjust the pedal so the tripdown switch activates like it should.
Rennlist Member
Joined: Jul 2001
Posts: 6,561
Likes: 113
From: New York
alternator charge batt
Update: Car started on first crank today, ran rough for a moment, then stabilized out. Let it run for 5m to recharge battery and warm up a bit, seems ok so shut down.
I'll start taking some things apart once it gets above freezing, too cold to work much right now. Thanks for the replies, one of the tasks will be to re-adjust the pedal so the tripdown switch activates like it should.
I'll start taking some things apart once it gets above freezing, too cold to work much right now. Thanks for the replies, one of the tasks will be to re-adjust the pedal so the tripdown switch activates like it should.
Nordschleife Master
Joined: Jan 2013
Posts: 5,945
Likes: 322
From: Kaukauna Wisconsin
A bit OT, but I've always wondered how long it takes for the alternator to charge. Seems it would depend on some variables like health of the batt and state of discharge for starters (pun). Since my maintainer takes much longer than 5 minutes to show a green light, I wonder if others have more to offer on this subject?
It depends.
How discharged is the battery?
How much is the alternator putting out?
Battery maintainers (float chargers) generally only put out an amp or two.
The alternator puts out a lot more (depending on how fast it's spinning).
The starter takes a lot of power to crank the engine over, but if it's only cranking for a few seconds, it's not discharging the battery much.
So if the battery was fully charged to begin with, and it only took a short crank to get the engine running, then it may only take a couple minutes to charge up the battery.
OTOH, if the battery was down some, the engine didn't start right away and had to be cranked for an extended amount of time, it will take longer to reach full charge.
Driving (engine spinning faster) will charge faster than idling. Accessories (lights, fan, radio) will draw power and leave less 'surplus' to go into the battery will make it take longer too.
Rennlist Member
Joined: Jul 2001
Posts: 6,561
Likes: 113
From: New York
Joe: That's makes sense, thanks, kinda what I thought. The 5 minutes might be adequate to charge It's freaking cold here too, but not Wisconsin cold.
Back on topic, Christopher, if the OAT is as cold as you said, assuming 5 minutes is the total run you refer to,(and your car is not in a heated garage) it isn't helping your moving parts. Many opinions here about starting the cars in winter and whether it benefits or hurts them when sitting, but it takes longer than that to get to operating temp in warm weather on this car.
Back on topic, Christopher, if the OAT is as cold as you said, assuming 5 minutes is the total run you refer to,(and your car is not in a heated garage) it isn't helping your moving parts. Many opinions here about starting the cars in winter and whether it benefits or hurts them when sitting, but it takes longer than that to get to operating temp in warm weather on this car.
Last edited by SteveG; Jan 1, 2018 at 02:59 PM. Reason: clearity amigo