inconsistent performance.
09-30-10, 08:54 AM
#1
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inconsistent performance.
I've had a problem for a long while now that has really been bothering me. Sometimes I'll get in my car and it will feel pretty strong, and then other times, it will feel gutless. I thought at first it might be related to the weather/temperature, but it really isn't. For example, we had a cool day earlier this week, and the car felt really good. Next time I got in the car, same weather, it felt like a dog again. The difference feels like 20-30hp, possibly more. I would say its either the injectors or something in the ignition system, but I don't really know. What do you guys think? The car is an '84 SE with full exhaust. Auxiliary ports do not function at all.
09-30-10, 11:40 AM
#5
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with a gsl-se you have a couple options!
fuel filter, and especially the little pick up sock in the tank are possibilities.
the other one is the thermal valve for the secondary throttle plates. they have them closed when the car is cold to limit power, just like the new bmw m5, and when the car warms up, they are supposed to open and then give you full power.
i see a LOT of the thermal vacuum switch valves being bad. they are expensive new (over $50), so i usually bypass it. its in the rear of the throttle body, white thing, two vacuum lines. on the FC they hooked it up backwards, so when the valve fails it fails with the secondary throttle open
the third option is a stuck auxillary port actuator, you should be able to reach in there and push down on em, and they move.
fuel filter, and especially the little pick up sock in the tank are possibilities.
the other one is the thermal valve for the secondary throttle plates. they have them closed when the car is cold to limit power, just like the new bmw m5, and when the car warms up, they are supposed to open and then give you full power.
i see a LOT of the thermal vacuum switch valves being bad. they are expensive new (over $50), so i usually bypass it. its in the rear of the throttle body, white thing, two vacuum lines. on the FC they hooked it up backwards, so when the valve fails it fails with the secondary throttle open
the third option is a stuck auxillary port actuator, you should be able to reach in there and push down on em, and they move.
09-30-10, 12:59 PM
#6
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fuel filter is actually new.
the idle is always the same (actually too low, 500rpm or so)
I'll check out the thermal valve. I noticed a large hose from the LIM that was just sitting there open, although it looked more like a coolant line? I'll post a picture of it later.
The Aux port are not functioning at the moment, so that isn't something that is variable.
the idle is always the same (actually too low, 500rpm or so)
I'll check out the thermal valve. I noticed a large hose from the LIM that was just sitting there open, although it looked more like a coolant line? I'll post a picture of it later.
The Aux port are not functioning at the moment, so that isn't something that is variable.
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10-02-10, 04:07 PM
#9
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How do I check the leading ignition to see if it is good or bad?
I took the intake tube off and looked at the throttle body, and here is what it looks like:
The butterflies closest to the camera, on bottom, move freely, and were sort of at a 20-30* angle when I took the intake tube off. I'm guessing these are the ones controlled by vacuum judging by the actuator/diaphragm they are connected to. Should they be totally closed with the engine off or what? How can I tell if they are functioning properly?
I took the intake tube off and looked at the throttle body, and here is what it looks like:
The butterflies closest to the camera, on bottom, move freely, and were sort of at a 20-30* angle when I took the intake tube off. I'm guessing these are the ones controlled by vacuum judging by the actuator/diaphragm they are connected to. Should they be totally closed with the engine off or what? How can I tell if they are functioning properly?
10-03-10, 09:27 AM
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10-03-10, 11:45 AM
#14
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So I took the vacuum line off (it broke at the other little valve of course) taped it up at the engine side and took it out for a drive. Mid-range and top-end felt noticeably stronger than before. It's pulling well past the buzzer, even without functioning auxiliary ports. I think I'm going to just remove the sleeves all together, when I get a chance. I can't wait to see what this little motor can do with a megasquirt map-tune and a nice cold air intake. Louis Armstrong anyone?? 
10-03-10, 01:57 PM
#16
You are really doing yourself and your GSL-SE an disservice by not having fully functioning 6 port actuators.
It is the main inherent design that give the GSL-SE the low end Torque that so many rotaries dream about.
The car is designed to run on 4 ports for low end, - giving you plenty of pep and power and torque.
It's what makes a stock GSL-SE so damn fun to drive. Unlike the 12A powered cars, it doesn't have to Rev and downshift every time it wants to move quickly.
Then open up the 6 ports under load to give you screaming high end. It's almost a form of VTEC (for you younger guys to understand.)
You really should take the lower intake apart, clean them up and make sure they are working correctly, and properly connected to the exhaust.
Trust me - I've had 6 ports engine with the sleeves hard wired open, and it was only fun in a high revving drag race.
Everywhere else in the power-band, the torque was horrible, even lower than stock.
Fix it!
It is the main inherent design that give the GSL-SE the low end Torque that so many rotaries dream about.
The car is designed to run on 4 ports for low end, - giving you plenty of pep and power and torque.
It's what makes a stock GSL-SE so damn fun to drive. Unlike the 12A powered cars, it doesn't have to Rev and downshift every time it wants to move quickly.
Then open up the 6 ports under load to give you screaming high end. It's almost a form of VTEC (for you younger guys to understand.)
You really should take the lower intake apart, clean them up and make sure they are working correctly, and properly connected to the exhaust.
Trust me - I've had 6 ports engine with the sleeves hard wired open, and it was only fun in a high revving drag race.
Everywhere else in the power-band, the torque was horrible, even lower than stock.
Fix it!
Last edited by Directfreak; 10-03-10 at 02:01 PM.
10-03-10, 02:03 PM
#17
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I've tried numerous ways to get them to work. They will not function off of exhaust gas because of my header/exhaust configuration, there simply is not enough pressure. I may, in the future, rig up some sort of linear actuator with an RPM switch, but for now I enjoy the way it drives.
10-03-10, 02:49 PM
#18
If you can't get the Aux ports to works off of exhaust pressure, then most likely they're carboned up. Time to take it all apart for a good cleaning. Then I can show you the simplest way there is to get the ports working off of the exhaust.
10-03-10, 03:14 PM
#19
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I took them all apart and they move pretty well. I cleaned and lubed the sleeves, and the diaphragms still hold pressure fine. I tried hooking them up with a direct feed from the header primary, but it wasn't enough pressure.
10-03-10, 11:12 PM
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air pump worked for me!
10-06-10, 02:56 PM
#22
I've tried numerous ways to get them to work. They will not function off of exhaust gas because of my header/exhaust configuration, there simply is not enough pressure. I may, in the future, rig up some sort of linear actuator with an RPM switch, but for now I enjoy the way it drives.
How do you know they don't work? I could not see mine open hardly at all when
revving the engine while idling. So I put some grease on the actuating rod so I could see any movement, and lo and behold, under load they opened up all the way. If you have cleaned them, and they move freely, I'm sure that when you are driving the car, they will open.
