Boosted GS Issues/Questions
Boosted GS Issues/Questions
Hey guys so I'm new to the whole big turbo car thing, never had one before...I noticed earlier today when I got on the car one time the A/F droped to around 10-10.4 and the power just cut real quick, like a fuel cut or boost cut so I let off and got back on and it did it again. What could that be? I had been driving of for about 15 mins and temp was normal before I boosted it. Could it might have just needed to be warmer? Also what should me A/F be at? It bounced around all day today, idle was between 13-14, driving was around 11-14 and ocasionally up to 16-17 when I would let off or just a little gas...What do you think?
Temp doesn't seem to affect it. It was 55 out today and it still had the same issue after I had been driving it all day long. Later today I got on it again and it went through 1st - 2nd - 3rd on boost just fine and it broke up in 4th again. I don't know what the deal is...
Also it seems to have a rough idle sometimes, don't know if that normal or not. Idle make the car sound like it has cams but it doesn't, mabye a miss?
Car is a 1999 GS300 NA-t, 62mm turbo, 255 pump, 650cc injectors...
A couple vids
http://www.youtube.com/watch?v=6vq2W...ature=youtu.be
http://www.youtube.com/watch?v=qRrsS...ature=youtu.be
Temp doesn't seem to affect it. It was 55 out today and it still had the same issue after I had been driving it all day long. Later today I got on it again and it went through 1st - 2nd - 3rd on boost just fine and it broke up in 4th again. I don't know what the deal is...
Also it seems to have a rough idle sometimes, don't know if that normal or not. Idle make the car sound like it has cams but it doesn't, mabye a miss?
Car is a 1999 GS300 NA-t, 62mm turbo, 255 pump, 650cc injectors...
A couple vids
http://www.youtube.com/watch?v=6vq2W...ature=youtu.be
http://www.youtube.com/watch?v=qRrsS...ature=youtu.be
If your running real rich it will break up and stop the boosting short. I assume the wastegate is plumbed back into the exhaust since I can't really hear it. If you could hear it and it was breaking up rich the dump would sound like a pulsing/machine gun type sound instead of a smooth steady rush of air.
But even not hearing the wastegate I'm not sure that seems much like rich breakup. It does seem kinda like fuel cut? ButI forgot what that car was tuned with, FIC right??
Really would help to he the AFR and Boost level at the same time in the shoot with the car doing that.
Your still only in the 4000's in that roll, does it ever boost up to 6k in different gears or under various loading??
The afr's will continuously move as you modulate the pedal and load on the engine, and shooting up when you let off throttle is normal. People have different views on what 'perfect' afr's should be depending on the fuel used and favoring on the side of safety or power. So I'll refrain having any opinion on that, you may end up needing to find a tuner local to you to help perfect the car.
Plus side is the car does sound pretty good!
GL, as it is a nice install and should be a blast once you get any small bugs worked out.
But even not hearing the wastegate I'm not sure that seems much like rich breakup. It does seem kinda like fuel cut? ButI forgot what that car was tuned with, FIC right??
Really would help to he the AFR and Boost level at the same time in the shoot with the car doing that.
Your still only in the 4000's in that roll, does it ever boost up to 6k in different gears or under various loading??
The afr's will continuously move as you modulate the pedal and load on the engine, and shooting up when you let off throttle is normal. People have different views on what 'perfect' afr's should be depending on the fuel used and favoring on the side of safety or power. So I'll refrain having any opinion on that, you may end up needing to find a tuner local to you to help perfect the car.
Plus side is the car does sound pretty good!
GL, as it is a nice install and should be a blast once you get any small bugs worked out.
Last edited by 99 GS3; Jan 11, 2012 at 03:14 PM.
Well in the first vid it sounds like you getting a misfire and OBD2 ecus will shut down the ignition. I see your CEL is on, get the codes to confirm. The 2nd vid looks like the idle is a bit low and the idle control valve is trying to compensate. It may be a boost leak from a small vac hose on the top of the motor. Good luck.
If that's the case then why don't you unplug the O2 sensor and have the ECU stay in open loop?
With my car at idle anything over 14.7 I get misfires and my car fluctuate but my car idles between 13.5 an 14.2 with a minor hiccup every now and then. when I punch it my car will hit the low 11's not in the 10's,that's too rich and it will cause your car to bog down. You need to tweak your map. Is this a street tune or dyno tune ? What engine management are you using ? I think you need fine tuning of you maps because it sounds like a tuning issue IMO.
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Well in the first vid it sounds like you getting a misfire and OBD2 ecus will shut down the ignition. I see your CEL is on, get the codes to confirm. The 2nd vid looks like the idle is a bit low and the idle control valve is trying to compensate. It may be a boost leak from a small vac hose on the top of the motor. Good luck.
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Right down the road from you in bowie. I'm taking the car over Ben at FE on tuesday and let him go through it.
Yeah I agree, I think it needs a retune. Its just running a haltech piggy right now, the previous owner had it tuned real rich to be safe I think.
With my car at idle anything over 14.7 I get misfires and my car fluctuate but my car idles between 13.5 an 14.2 with a minor hiccup every now and then. when I punch it my car will hit the low 11's not in the 10's,that's too rich and it will cause your car to bog down. You need to tweak your map. Is this a street tune or dyno tune ? What engine management are you using ? I think you need fine tuning of you maps because it sounds like a tuning issue IMO.
SRT is close to you as well, and they have done lots and lots of NA-T w/ Haltech, it may be worth giving them a call as well.
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dumdumgreg
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Oct 29, 2008 10:06 PM
