warming up? - Page 2

Krem · 10-20-2009, 06:37 AM

:\ yea... lots of leaks and kinks to still work out... I really do appreciate the insight, especially since you earlier stated you didn't feel like mentoring and I feel like that's what I'm coaxing out of you. For that, I'm sorry.. but at the same time, I'm grateful you're giving the time it takes to help me get the right idea of what's going on under my hood...

One last thing... is the ignition timing done thru the cams even tho it's naturally aspired? or from the distributor since it is naturally aspired? Cause I just had the distributor replaced and had timing done at top dead center... just not sure which type of timing that was...

cre · 10-20-2009, 07:15 AM

There are two types of timing, doesn't matter if the car is N/A or Turbo: mechanical and spark.

Mechanical timing is where you align everything so that piston #1 is at 0? or TDC (Top Dead Center) and the valves are precisely where specified by the manufacturer and the distributor and cam position sensor (yes our N/A's do have a CPS inside the distributor) point to the #1 position.

Spark timing define when the spark occurs with relation to the location of the piston. The spark is actually generated in *advance* of the piston reaching TDC; hence the term "spark or ignition advance". The thing is that what you're trying to achieve here is a situation where half of the fuel in the cylinder has been burned by the time the crank reaches about 20? ATDC (After Top Dead Center) as this is where the most power is made. So, in order to acheive this the ECU adjusts the spark advance constantly while listening to the knock sensors to hear is the spark occured too soon causing a shock to the system (this occurs if the advance is too great and the fuel is igniting sooner than predicted). As a result of these factors if your timing is too far advanced or retarded you may see a power loss (and possibly a severe one) and your engine and exhaust temps will change. Your spark timing and the burn rate of the fuel is important in determining the octane you want to use in your vehicle. Too high and may lose power... too low and you may lose power... interesting eh?

Setting the ignition timing on these cars is very easy... so easy that it seems a lot of mechanics just can't manage the feat.

EDIT:Oh, and I didn't say I wouldn't help... just not about to take anyone by the hand and walk them through the wonderful world of automotive repair and modification. I am willing to help you out here and there.

cre · 10-20-2009, 07:29 AM

I should add that the ECU has a couple different maps or charts that it uses to determine the base ignition timing for a given engine temp, air temp, RPM and throttle position. The map used when the engine is cold is fairly conservative. The only map which is more conservative is the "limp mode" map which pulls a LOT of the advance out, this results in a very weak engine performance wise and can result in a rather hot engine due to the pulled timing. Limp mode is engaged when certain error codes are registered by the ECU (such as code 52: knock sensor error or malfunction).

Your spark advance and mechanical timing also affect the temperatures within the engine. Burn the fuel too soon and you've got a LOT of heat which has to go somewhere and the valves aren't letting it out... Burn the fuel too late and it's still burning when the valves open... cooler engine, HOT exhaust and as such hot O2 sensor and hot hot hot valves.

Krem · 10-26-2009, 11:35 PM

Quote:

Originally Posted by cre

Attachment 2450

The sensor plug we fixed, according to this pic, is actually BEHIND the BVSV hoses... and has the same kinda plug as the ECU coolant sensor... but I've confirmed the ECU coolant sensor is lower than the plug we fixed... any idea what I might have fixed?

cre · 10-27-2009, 12:40 AM

Brown plug? That's the Cols Start Injector time switch. It's a temp sensor which determines if the CSI is used and limits the duration that it's used while the engine is being cranked. The CSI (Cold Start Injector) is ONLY engaged while the engine is being cranked AND the coolant is cold. It can fix sluggishness issues while starting the car in cold weather; Generally the car will start without it in such conditions, it will just take longer. The sensor is not used for any other purposes and does not affect the ECU's operations while the vehicle is running.

Krem · 10-27-2009, 12:59 AM

yea, it was a brown plug... but now it's two seperate elec connectors with sleeves around them to prevent contact.. used ohm meter to determine on the old plug to determine which terminal which wire went on.. However, after doing said fix, the car has a harder time starting up cold than it did before and seems more sluggish than it did when this sensor wasn't plugged in correctly... sounds almost opposite of what you mentioned...

cre · 10-27-2009, 01:03 AM

The injector may be leaking. If it is leaking you'd see those issues whether it's plugged in or not. If it's just dumping too much fuel the sluggishness should go away after a minute of driving so the extra fuel is burned off. I'm not sure if it matters which wire is connected to which terminal... if it does then you may have them switched resulting in the injector always being on.

Krem · 10-27-2009, 01:23 AM

could this issue be connected to the ERG bypass setup I've described in another thread? basically the purge port on the charcoal canister is plugged to an input to the air intake, just before the intake manifold... it's not plugged into the BVSV. Infact, the plastic light green colored connector for the hoses is broken and needs to be replaced.. I still haven't found a coolant leak, no signs of BHG either... wondering if I'm smelling vapors through there.

Another thing I did notice today, the coolant in the resevoir and the resevoir hose are chillin... not hot at all.. the part of the resevoir hose closest to radiator is, however, hot... due to surrounding thermals. Dunno if that's bad or norm... just thought I'd throw it out since my coolant system seems jacked..

tak2099 · 10-27-2009, 03:03 AM

Cre, I must say, you are quite knowledgeable. Your detailed posts are text book quality!

cre · 10-27-2009, 03:15 AM

The CC is part of the Evap system (Evaporative emissions); It has nothing to do with the EGR system. I've already discussed the CC's routing and the reason for the BVSV's connection being essential for a number of reasons including: fuel pump longevity and fuel tank pressure control... I'm not going to discuss this any further. Get another BVSV from any 80's through mid 90's Toyota at a salvage yard... pick up a couple as they run over $100 new.

I will add, because I don't recall if I mentioned it specifically, that routing the CC straight to the intake can cause added richness at startup and lean the fuel setup once the engine has sucked all the gasoline vapors out of the engine creating a vacuum in the fuel tank... fix the damned thing and then you won't have to keep worrying if that's the problem.

Hose temperature means dick.. the area in front of the radiator sees great cooling. Watch the level of the coolant in the reservoir; note where it is when the engine is cold and note where it is when it is hot (I believe the proper level for each is marked on all of the overflow tanks, not just mine). If the level doesn't change then you have excessive air in your coolant system and.... you guessed it... a leak. A leak includes coolant leaking into the coolant chamber or getting blown out of the over flow tank due to combustion gasses escaping the cylinder into the coolant system at high RPMs. A lithmus test (acidity test to the guy at the parts store) will tell you if your HG is allowing gasses into the coolant.

10-20-2009, 07:15 AM	#12
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	There are two types of timing, doesn't matter if the car is N/A or Turbo: mechanical and spark. Mechanical timing is where you align everything so that piston #1 is at 0? or TDC (Top Dead Center) and the valves are precisely where specified by the manufacturer and the distributor and cam position sensor (yes our N/A's do have a CPS inside the distributor) point to the #1 position. Spark timing define when the spark occurs with relation to the location of the piston. The spark is actually generated in advance of the piston reaching TDC; hence the term "spark or ignition advance". The thing is that what you're trying to achieve here is a situation where half of the fuel in the cylinder has been burned by the time the crank reaches about 20? ATDC (After Top Dead Center) as this is where the most power is made. So, in order to acheive this the ECU adjusts the spark advance constantly while listening to the knock sensors to hear is the spark occured too soon causing a shock to the system (this occurs if the advance is too great and the fuel is igniting sooner than predicted). As a result of these factors if your timing is too far advanced or retarded you may see a power loss (and possibly a severe one) and your engine and exhaust temps will change. Your spark timing and the burn rate of the fuel is important in determining the octane you want to use in your vehicle. Too high and may lose power... too low and you may lose power... interesting eh? Setting the ignition timing on these cars is very easy... so easy that it seems a lot of mechanics just can't manage the feat. EDIT:Oh, and I didn't say I wouldn't help... just not about to take anyone by the hand and walk them through the wonderful world of automotive repair and modification. I am willing to help you out here and there. Last edited by cre; 10-20-2009 at 07:17 AM.

10-27-2009, 03:03 AM	#19
tak2099 3" Exhaust Join Date: Jul 2007 Location: ohio Posts: 90	Cre, I must say, you are quite knowledgeable. Your detailed posts are text book quality! __________________ 1988 supra turbo. In process of modding:Roll cage, seats, dp, 3" intercooler, fuel upgrades, and turbo upgrades next.

10-20-2009, 06:37 AM	#11
Krem 3" Exhaust Join Date: Sep 2009 Location: Las Vegas Posts: 167	:\ yea... lots of leaks and kinks to still work out... I really do appreciate the insight, especially since you earlier stated you didn't feel like mentoring and I feel like that's what I'm coaxing out of you. For that, I'm sorry.. but at the same time, I'm grateful you're giving the time it takes to help me get the right idea of what's going on under my hood... One last thing... is the ignition timing done thru the cams even tho it's naturally aspired? or from the distributor since it is naturally aspired? Cause I just had the distributor replaced and had timing done at top dead center... just not sure which type of timing that was...

10-20-2009, 07:29 AM	#13
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	I should add that the ECU has a couple different maps or charts that it uses to determine the base ignition timing for a given engine temp, air temp, RPM and throttle position. The map used when the engine is cold is fairly conservative. The only map which is more conservative is the "limp mode" map which pulls a LOT of the advance out, this results in a very weak engine performance wise and can result in a rather hot engine due to the pulled timing. Limp mode is engaged when certain error codes are registered by the ECU (such as code 52: knock sensor error or malfunction). Your spark advance and mechanical timing also affect the temperatures within the engine. Burn the fuel too soon and you've got a LOT of heat which has to go somewhere and the valves aren't letting it out... Burn the fuel too late and it's still burning when the valves open... cooler engine, HOT exhaust and as such hot O2 sensor and hot hot hot valves.

10-27-2009, 12:40 AM	#15
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Brown plug? That's the Cols Start Injector time switch. It's a temp sensor which determines if the CSI is used and limits the duration that it's used while the engine is being cranked. The CSI (Cold Start Injector) is ONLY engaged while the engine is being cranked AND the coolant is cold. It can fix sluggishness issues while starting the car in cold weather; Generally the car will start without it in such conditions, it will just take longer. The sensor is not used for any other purposes and does not affect the ECU's operations while the vehicle is running.

10-27-2009, 12:59 AM	#16
Krem 3" Exhaust Join Date: Sep 2009 Location: Las Vegas Posts: 167	yea, it was a brown plug... but now it's two seperate elec connectors with sleeves around them to prevent contact.. used ohm meter to determine on the old plug to determine which terminal which wire went on.. However, after doing said fix, the car has a harder time starting up cold than it did before and seems more sluggish than it did when this sensor wasn't plugged in correctly... sounds almost opposite of what you mentioned...

10-27-2009, 01:03 AM	#17
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	The injector may be leaking. If it is leaking you'd see those issues whether it's plugged in or not. If it's just dumping too much fuel the sluggishness should go away after a minute of driving so the extra fuel is burned off. I'm not sure if it matters which wire is connected to which terminal... if it does then you may have them switched resulting in the injector always being on.

10-27-2009, 01:23 AM	#18
Krem 3" Exhaust Join Date: Sep 2009 Location: Las Vegas Posts: 167	could this issue be connected to the ERG bypass setup I've described in another thread? basically the purge port on the charcoal canister is plugged to an input to the air intake, just before the intake manifold... it's not plugged into the BVSV. Infact, the plastic light green colored connector for the hoses is broken and needs to be replaced.. I still haven't found a coolant leak, no signs of BHG either... wondering if I'm smelling vapors through there. Another thing I did notice today, the coolant in the resevoir and the resevoir hose are chillin... not hot at all.. the part of the resevoir hose closest to radiator is, however, hot... due to surrounding thermals. Dunno if that's bad or norm... just thought I'd throw it out since my coolant system seems jacked..

10-27-2009, 03:15 AM	#20
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	The CC is part of the Evap system (Evaporative emissions); It has nothing to do with the EGR system. I've already discussed the CC's routing and the reason for the BVSV's connection being essential for a number of reasons including: fuel pump longevity and fuel tank pressure control... I'm not going to discuss this any further. Get another BVSV from any 80's through mid 90's Toyota at a salvage yard... pick up a couple as they run over $100 new. I will add, because I don't recall if I mentioned it specifically, that routing the CC straight to the intake can cause added richness at startup and lean the fuel setup once the engine has sucked all the gasoline vapors out of the engine creating a vacuum in the fuel tank... fix the damned thing and then you won't have to keep worrying if that's the problem. Hose temperature means dick.. the area in front of the radiator sees great cooling. Watch the level of the coolant in the reservoir; note where it is when the engine is cold and note where it is when it is hot (I believe the proper level for each is marked on all of the overflow tanks, not just mine). If the level doesn't change then you have excessive air in your coolant system and.... you guessed it... a leak. A leak includes coolant leaking into the coolant chamber or getting blown out of the over flow tank due to combustion gasses escaping the cylinder into the coolant system at high RPMs. A lithmus test (acidity test to the guy at the parts store) will tell you if your HG is allowing gasses into the coolant.