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What makes a car go into closed loop?????

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fbodlovr

1/4 Mile Freak
Joined
Aug 14, 2005
Messages
703
I have a scanmatser 2.1 and even after letting it warm up and go into closed loop? the little dot in between the 0's is still blinking. Doesnt this mean that its in open loop and thinks its not warmed up? Its definitely warmed up when it is still blinking. Also the bl and one other thing are sitting RIGHT on 128 which i thought was only suppost to happen when it is in open loop warming up.

Thanks :)
 
closed loop

Don't know much about scanmaster.
Closed loop is attained when O2 sensor reaches 600 degrees and car is at operating temp. It can go in and out when idling,etc. Might check your O2 sensor,cross counts. O2 sensor counts should be changing often.
 
here are the values. Do you see anything here that might indicate why this is happening?

The screen once started shows around 734 0.0
AF 06-07
L8 40-42
INT 128
BL 128
CLT -39 Bad accouring to scanmaster
ATS 61-63
R 850-900
TPS .42-.44
IAC 64-68
CC 01 & 65 were what I saw two different times.
 
Looks like your coolant temp sender is bad or has a wiring prob. Should show ambient temp and go up when the motor warms up.
 
Won't go into closed loop until it sees close to 160 degrees. If the temp sensor is showing below freezing temps it will never go into closed loop.
 
SLOW_85 said:
http://www.geocities.com/gnowner85/in11.html
#2 is the ecm coolant sensor.
#3 is for the idiot dash light.
The O2 sensor is located in the passenger header, below the up-pipe connection.

Hey, I looked at your post and went to that site. I went over one pic just to look at some, and I found this one. http://www.geocities.com/gnowner85/005.html What is that restriction part close to the wastegate? Ive seen someone mention it once, but didnt get what it was used for.
 
fbodlovr said:
Hey, I looked at your post and went to that site. I went over one pic just to look at some, and I found this one. http://www.geocities.com/gnowner85/005.html What is that restriction part close to the wastegate? Ive seen someone mention it once, but didnt get what it was used for.

It should have the little Y fitting. One side(turbo line) has the restriction.
Without you have unlimited boost. It forces the boost pressure to the wastegate solenoid.
You need to check out the coolant temp sender and figure put why it's reading so low. It gives the ecm input on the motor temp.
 
Ive replaced the coolant temp sensor. As to the y fitting. Do you mean without it the wastegate wont open properly? I guess I dont see the big reason for have it. Ive got a bad pass side exhaust header and i have only gotten the boost to run up to 8psi. When I get that fixed, does that mean without the y fitting the boost is going to shoot threw the roof?
 
With no restriction you will have slow spool and low boost. The restriction should face the compressor side of the turbo. You want to restrict the overall airflow to the wastegate and solenoid.
 
Ive got an 84 gn. I dont think those kits will fit my car. they are saying its for the 86 87 style setup. Is there anwhere I can get a setup for an 84 gn, or maybe just the y adapter. Also, the adjustable wastegate has two ports on it, those kits are only showing one line going to the wastegate.

Is this something that I REALLY need?
 
I used it on mine, but mine was a single wastegate, not a dual.

Does your NOT have it right now? It may be below the turbo, somewhat hidden. Take a look, you may (should) already have it on there. I may have an extra T with the correct orifice, I will take a look. See what you have.
 
Hey squid. My wastegate does have the dual port things. When we got the car it had SOME of the lines replaced already, and that was one of them. I guess im not sure if a dealer close to me would have one or not. Do you think this would cause boost loss?
 
fbodlovr said:
Ive replaced the coolant temp sensor. As to the y fitting. Do you mean without it the wastegate wont open properly? I guess I dont see the big reason for have it. Ive got a bad pass side exhaust header and i have only gotten the boost to run up to 8psi. When I get that fixed, does that mean without the y fitting the boost is going to shoot threw the roof?

I got it backwards. It will cause low boost. Without the restrictor,you get whatever boost the wastegate actuator is set at.
Might try Brian at gbodyparts.com. I think the orifice sizes are different between the 84-85,86-87's. I have an extra if you can't locate one.

From Search

Carl Ijames said:
Remember the restrictor in the y-hose? It goes closest to the compressor
outlet, and the solenoid and wastegate actuator are on the other two legs of
the tee. When the solenoid is closed (and the actuator isn't leaking :-))
there is no flow once the tubing is pressurized and thus no pressure drop
and so the actuator gets the full compressor outlet pressure. When the
solenoid opens it lets air bleed out, and now there is flow and a pressure
drop across the restrictor so the actuator gets less pressure and closes up
some. Another way to look at is that it takes more compressor outlet
pressure to get the same actuator pressure as before. This is how the
solenoid raises the boost over the mechanical setting of the wastegate. The
ecm doesn't measure boost, it just has a table of duty cycles for the
solenoid valve (the higher the duty cycle the more air the valve bleeds off
and so the greater the pressure drop across the restrictor) vs. rpm, another
table vs. tps that is all 1's in the stock chip, and then a multiplier to
reduce the duty cycle for 3rd gear and another multiplier for 4th gear. The
ecm leaves the solenoid turned off until the maf pass a threshold, 76 gps
stock.

If you put the restrictor in the y-hose in wrong, so the restrictor is
closest to the solenoid, then the actuator is getting its pressure before
the restrictor (directly from the compressor outlet) and so the boost is
about what the mechanical setting gives. That's why you see 12-14 psi boost
if you get the hose on wrong. The other way to get the restrictor in wrong
is to put it closest to the actuator. In this case there is no flow through
the restrictor and so no pressure drop there, and even when the solenoid
valve is open since there is no restriction in the supply line from the
compressor outlet there is basically no pressure drop and so again, the
actuator sees the full compressor outlet pressure and the boost is low.

Finally, you might say, well, why not make the restrictor hole very, very
small. When I said that there was no flow to the actuator earlier, I meant
in the steady state once the actuator was holding the flap valve open at
some position. To get to that position the diaphragm has to move and some
air has to flow to make that happen. The smaller the restrictor the slower
this will be, and eventually you will see a boost spike (the boost will
overshoot the setpoint by a few psi then come back down to the setpoint)
because the actuator isn't able to bleed off exhaust flow fast enough. Flow
is also required to pressurize all the tubing leading to the solenoid valve,
which is pretty close, but if you replace it with a manual bleed valve and
put that inside the car you now have many more feet of tubing to pressurize
and sometimes this will also cause a boost spike. Going bigger than
necessary on the restrictor makes the controls work really fast but wastes
some of your boost. Also, the internal orifice in the solenoid valve is
calibrated for the size of the orifice in the restrictor, and when GM had
that batch several years ago with smaller holes in them the solenoid was
bleeding off more air that expected and the final boost was too high.

__________________

Regards,

Carl Ijames
 
I guess Im STILL confused on this. Im not understanding what will happen if that is NOT in there. it only talks about it being the right way, and backwards.
 
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