Thank-you Dr. Haas for your article, it really helps a layman get a better introductory understanding of the fluid dynamics of an PCMO engine. I support thee!
Reducing wear at startup on a low service engine
- Thread starter zoomie
- Start date
- Status
A lot of cars do have clear flood mode, but I also tried it on quite a few that don't.
Why just start it up? Extended cranking can build almost 9 psi on my car (enough to show oil pressure on the dummy gauge), more than enough to move oil the top end and prime the system.
Why just start it up? Extended cranking can build almost 9 psi on my car (enough to show oil pressure on the dummy gauge), more than enough to move oil the top end and prime the system.
Originally Posted By: river_rat
Well that what I though too, but read my post on the previous page. That's why I recently changed my mind about extended cranking.
I don't like to do extended cranking. Some new cars let the crank do 2 complete revolutions before firing. My TL supposedly does this.
Well that what I though too, but read my post on the previous page. That's why I recently changed my mind about extended cranking.
I don't like to do extended cranking. Some new cars let the crank do 2 complete revolutions before firing. My TL supposedly does this.
Ya. IIRC, it called a slow fire system. It has to count so many "pips" from the camshaft or crankshaft sensor. My Tacoma does that.
The Blazer I had before fired right away...when it started at all.
By 26K miles it would crank forever before starting. I don't know what was wrong with it that time. Wierd.
The Blazer I had before fired right away...when it started at all.
By 26K miles it would crank forever before starting. I don't know what was wrong with it that time. Wierd.
Originally Posted By: BuickGN
Originally Posted By: river_rat
Well that what I though too, but read my post on the previous page. That's why I recently changed my mind about extended cranking.
I don't like to do extended cranking. Some new cars let the crank do 2 complete revolutions before firing. My TL supposedly does this.
And FWIW, the Toyota/Lex hybrids, which in urban driving do far more engine starting and stopping than most cars (mostly hot though) have a specifically programmed-in feature for starting. Motor-Generator-1 (the smaller one that's connected to the center shaft of the PGS) spins the ICE to about 1000 rpms before it orders up fuel and spark. This promotes smooth ICE starts, and ensures that the pump has built oil pressure before the ICE sees real driving loads on critical parts. These cars have neither traditional starters, nor alternators, nor PS pumps. MG1 in effect acts as both a starter motor and an alternator if needed (the inverters normally make plenty of AC drawing from the hefty current and voltage sent from the TB).
Anyway, all this suggests to me that there is legitimate concern about startup wear, even in a warm or hot engine. Why would have Toyota bothered with such systems if not?
Originally Posted By: river_rat
Well that what I though too, but read my post on the previous page. That's why I recently changed my mind about extended cranking.
I don't like to do extended cranking. Some new cars let the crank do 2 complete revolutions before firing. My TL supposedly does this.
And FWIW, the Toyota/Lex hybrids, which in urban driving do far more engine starting and stopping than most cars (mostly hot though) have a specifically programmed-in feature for starting. Motor-Generator-1 (the smaller one that's connected to the center shaft of the PGS) spins the ICE to about 1000 rpms before it orders up fuel and spark. This promotes smooth ICE starts, and ensures that the pump has built oil pressure before the ICE sees real driving loads on critical parts. These cars have neither traditional starters, nor alternators, nor PS pumps. MG1 in effect acts as both a starter motor and an alternator if needed (the inverters normally make plenty of AC drawing from the hefty current and voltage sent from the TB).
Anyway, all this suggests to me that there is legitimate concern about startup wear, even in a warm or hot engine. Why would have Toyota bothered with such systems if not?
OVERKILL
$100 Site Donor 2021
Originally Posted By: Ben99GT
Originally Posted By: demarpaint
I like that idea, how far back has Ford been set up like that?
Every gasoline EFI Ford I've owned has had that feature, so from at least from '95 and probably earlier.
1986. EEC-IV AFAIK.
Originally Posted By: demarpaint
I like that idea, how far back has Ford been set up like that?
Every gasoline EFI Ford I've owned has had that feature, so from at least from '95 and probably earlier.
1986. EEC-IV AFAIK.
Originally Posted By: river_rat
Ya. IIRC, it called a slow fire system. It has to count so many "pips" from the camshaft or crankshaft sensor. My Tacoma does that.
The Blazer I had before fired right away...when it started at all.
By 26K miles it would crank forever before starting. I don't know what was wrong with it that time. Wierd.
My GN was that way. Using a cam and crank sensor, it could take 2 revolutions or half a revolution to start depending on where it stopped.
Ya. IIRC, it called a slow fire system. It has to count so many "pips" from the camshaft or crankshaft sensor. My Tacoma does that.
The Blazer I had before fired right away...when it started at all.
By 26K miles it would crank forever before starting. I don't know what was wrong with it that time. Wierd.
My GN was that way. Using a cam and crank sensor, it could take 2 revolutions or half a revolution to start depending on where it stopped.
vs the LT-1 engines with Opti-Spark which provides instant starts
Quote:
"NEVER"...Mobil 1 synthetics
Why's that?
"NEVER"...Mobil 1 synthetics
Why's that?
Originally Posted By: zoomie
Quote:
"NEVER"...Mobil 1 synthetics
Why's that?
Yeah,what he asked??
Quote:
"NEVER"...Mobil 1 synthetics
Why's that?
Yeah,what he asked??
OVERKILL
$100 Site Donor 2021
Maybe it isn't seeing full WOT? Because it worked on my '87 GT.
Originally Posted By: lanteau
My 1990 Thunderbird Super Coupe (SC 3.8L) has an EEC-IV computer and I tried a WOT start yesterday and she fired right up and revved to 4k before I could get off the pedal LOL. No cold start cranking here.
Originally Posted By: lanteau
My 1990 Thunderbird Super Coupe (SC 3.8L) has an EEC-IV computer and I tried a WOT start yesterday and she fired right up and revved to 4k before I could get off the pedal LOL. No cold start cranking here.
Hmm, maybe I should try it again and make sure the pedal is FULLY mashed into the floor LOL. I could also try it on our 88 Mustang GT too, just figured they would have a very similar computer. My SC computer controls a little bit more but I think it still is very similar.
Originally Posted By: ekpolk
And FWIW, the Toyota/Lex hybrids, which in urban driving do far more engine starting and stopping than most cars (mostly hot though) have a specifically programmed-in feature for starting. Motor-Generator-1 (the smaller one that's connected to the center shaft of the PGS) spins the ICE to about 1000 rpms before it orders up fuel and spark. This promotes smooth ICE starts, and ensures that the pump has built oil pressure before the ICE sees real driving loads on critical parts. These cars have neither traditional starters, nor alternators, nor PS pumps. MG1 in effect acts as both a starter motor and an alternator if needed (the inverters normally make plenty of AC drawing from the hefty current and voltage sent from the TB).
Anyway, all this suggests to me that there is legitimate concern about startup wear, even in a warm or hot engine. Why would have Toyota bothered with such systems if not?
You are correct, there is a concern of increased bearing wear in hot (but not cold) engine on restart. It is well explained in this PDF on page 4 under the paragraph Tempereture of the Oil (sorry, could not copy and paste):
http://www.zddplus.com/TechBrief11 - Internal Combustion Engine Lubrication.pdf
So, thicker is sometimes better.
I got the link from this thread:
https://bobistheoilguy.com/forums/threads/higher-viscosity-better-hydrodynamic-film.111196/
And FWIW, the Toyota/Lex hybrids, which in urban driving do far more engine starting and stopping than most cars (mostly hot though) have a specifically programmed-in feature for starting. Motor-Generator-1 (the smaller one that's connected to the center shaft of the PGS) spins the ICE to about 1000 rpms before it orders up fuel and spark. This promotes smooth ICE starts, and ensures that the pump has built oil pressure before the ICE sees real driving loads on critical parts. These cars have neither traditional starters, nor alternators, nor PS pumps. MG1 in effect acts as both a starter motor and an alternator if needed (the inverters normally make plenty of AC drawing from the hefty current and voltage sent from the TB).
Anyway, all this suggests to me that there is legitimate concern about startup wear, even in a warm or hot engine. Why would have Toyota bothered with such systems if not?
You are correct, there is a concern of increased bearing wear in hot (but not cold) engine on restart. It is well explained in this PDF on page 4 under the paragraph Tempereture of the Oil (sorry, could not copy and paste):
http://www.zddplus.com/TechBrief11 - Internal Combustion Engine Lubrication.pdf
So, thicker is sometimes better.
I got the link from this thread:
https://bobistheoilguy.com/forums/threads/higher-viscosity-better-hydrodynamic-film.111196/
Originally Posted By: OVERK1LL
Maybe it isn't seeing full WOT? Because it worked on my '87 GT.
Originally Posted By: lanteau
My 1990 Thunderbird Super Coupe (SC 3.8L) has an EEC-IV computer and I tried a WOT start yesterday and she fired right up and revved to 4k before I could get off the pedal LOL. No cold start cranking here.
That is exactly what I'm afraid will happen with the 88 E-150. I'll stick to the pre-luber with that van. If I feel brave enough I might try it with the 93 Aerostar.
Maybe it isn't seeing full WOT? Because it worked on my '87 GT.
Originally Posted By: lanteau
My 1990 Thunderbird Super Coupe (SC 3.8L) has an EEC-IV computer and I tried a WOT start yesterday and she fired right up and revved to 4k before I could get off the pedal LOL. No cold start cranking here.
That is exactly what I'm afraid will happen with the 88 E-150. I'll stick to the pre-luber with that van. If I feel brave enough I might try it with the 93 Aerostar.
Originally Posted By: OVERK1LL
Maybe it isn't seeing full WOT? Because it worked on my '87 GT.
Originally Posted By: lanteau
My 1990 Thunderbird Super Coupe (SC 3.8L) has an EEC-IV computer and I tried a WOT start yesterday and she fired right up and revved to 4k before I could get off the pedal LOL. No cold start cranking here.
TPS out of adjustment or leaking injectors will cause it to start during clear flood.
Maybe it isn't seeing full WOT? Because it worked on my '87 GT.
Originally Posted By: lanteau
My 1990 Thunderbird Super Coupe (SC 3.8L) has an EEC-IV computer and I tried a WOT start yesterday and she fired right up and revved to 4k before I could get off the pedal LOL. No cold start cranking here.
TPS out of adjustment or leaking injectors will cause it to start during clear flood.
- Status
Similar threads
