shadow Posted October 2, 2008 Report Share Posted October 2, 2008 I noticed on my trip home that all of a sudden when I push down and activate the turbo it surges in and out of boost? At first I thought it was the tranny bucking but no its the turbo? What could have all of a sudden happened to it? Will I cause any more damage driving it this way? Thanks Chris Quote Link to comment Share on other sites More sharing options...
mfewtrail Posted October 4, 2008 Report Share Posted October 4, 2008 Chris, does the check engine light come on when this happens? Also, when it happens, does it boost, die out, then start boosting again a short time later(few seconds?)...OR does the boost just fluxiate up and down the whole time. By the way, what chip are you running and does the car have a stock airbox or a K&N filter? Quote Link to comment Share on other sites More sharing options...
meltboy1 Posted October 4, 2008 Report Share Posted October 4, 2008 check the vacuum lines, I had a similar problem and it was a cracked vacuum line goin to the wastegate Quote Link to comment Share on other sites More sharing options...
krenzy Posted October 4, 2008 Report Share Posted October 4, 2008 Chris, does the check engine light come on when this happens? Also, when it happens, does it boost, die out, then start boosting again a short time later(few seconds?)...OR does the boost just fluxiate up and down the whole time. Are you referring to Overboost? Quote Link to comment Share on other sites More sharing options...
mfewtrail Posted October 4, 2008 Report Share Posted October 4, 2008 Chris, does the check engine light come on when this happens? Also, when it happens, does it boost, die out, then start boosting again a short time later(few seconds?)...OR does the boost just fluxiate up and down the whole time. Are you referring to Overboost? Yes, if it dies out, and then power comes back(once certain conditions are met). Meltboy, that's what I was getting at with the boost "fluxiate" info I mentioned. It probably is a hole in the vacuum lines there OR a possible wastegate control solenoid issue. Quote Link to comment Share on other sites More sharing options...
shadow Posted October 4, 2008 Author Report Share Posted October 4, 2008 Chris, does the check engine light come on when this happens? Also, when it happens, does it boost, die out, then start boosting again a short time later(few seconds?)...OR does the boost just fluxiate up and down the whole time. By the way, what chip are you running and does the car have a stock airbox or a K&N filter? Thanks for the reply! The car has a stock chip with a K&N cone filter connected to the turbo. I am getting no check engine lights at all? The car starts and drives fine but if i gun it I can feel the power droping and rising similar to a low bucking but as soon as I lay off the throttle its fine. If I pull off from a stop under normal driving conditions there is no problems but if I gun it the surging happens? Thanks Chris Quote Link to comment Share on other sites More sharing options...
TGP5sp90 Posted October 6, 2008 Report Share Posted October 6, 2008 Almost sounds like the diaphram is releasing at the wastegate. I say first off find out if it is a wastegate problem or if it is an electronic problem. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted October 6, 2008 Report Share Posted October 6, 2008 coil packs? Quote Link to comment Share on other sites More sharing options...
RareGMFan Posted October 10, 2008 Report Share Posted October 10, 2008 I suppose it's possible, but I don't think it's the turbo itself. If there is a fuel or electrical problem, you will fluctuate in power, which will naturally cause the turbo to fluctuate boost. My TSTE would do something similar when I bought it where it would get to full boost, then power would just cut (nearly causing my face to meet the steering wheel), and power would be right back on once it dropped off in RPMs for a second. There are many possible causes, but for me, that problem almost completely disappeared when I replaced the spark plugs. The old ones had something ridiculous for gaps like .60. Obviously hadn't been changed in a while. My guess is the boost was blowing out the spark plugs on account of the way too large gap on them, because I very seldom got that problem again after that, and when it happened, it was no where near as severe as before. Quote Link to comment Share on other sites More sharing options...
shadow Posted October 10, 2008 Author Report Share Posted October 10, 2008 yeah the car drives fine but this only happens under wot? The bucking/surging makes me feel like I am going to do more damage driving it so I have not been for the past month. No black smoke or check engine lights are coming on? I am afraid the dealer is goinf to charge me a small fortune to diagnose the problem due to the age and it being a rare GM engine setup. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted October 11, 2008 Report Share Posted October 11, 2008 I would never let the dealer touch it. I would go to the parts desk and get six ac delco plugs though. I agree, it needs plugs. the gap is too big and boost is blowing out the spark. Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted October 11, 2008 Report Share Posted October 11, 2008 AC Delco R42LTS gapped at .030" Quote Link to comment Share on other sites More sharing options...
RareGMFan Posted October 11, 2008 Report Share Posted October 11, 2008 yeah the car drives fine but this only happens under wot? The bucking/surging makes me feel like I am going to do more damage driving it so I have not been for the past month. Same problem with mine. It didn't do it till I went WOT, and the boost came close to maxing out. I'd take my foot off the second it cut off because it would scare the crap out of me. You certainly have nothing to loose by giving it a tune-up. And I agree with Garrett. The competence of dealer mechanics is poor enough with CURRENT cars, let alone an 18+ year old 3.1L V6, and a turbo charged one at that (which most have never seen in their lives). I'm sure between all the knowledgeable people here, you can get to the bottom of this without relying on a so-called "mechanic" to figure it out. Quote Link to comment Share on other sites More sharing options...
TGP5sp90 Posted October 11, 2008 Report Share Posted October 11, 2008 I also agree with garret & RareGM you need to find a close friend that maybe ASC certified atleast to get a really good look to in locating this annoying problem. Do not take it to a dealership, I won't go in to great detail , but you are saving your time and money. Plus this way you learn something in the process. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted October 11, 2008 Report Share Posted October 11, 2008 If he is running a stock chip with only 9 psi though, could he get away with a .035 or even the original .040 and still get some more fuel efficiency out of it? I mean the longer spark could burn a little more fuel at idle and cruise I think. I know I was getting 30 mpg when I first bought the red car and the back 3 plugs were the originals Quote Link to comment Share on other sites More sharing options...
krenzy Posted October 12, 2008 Report Share Posted October 12, 2008 I had this problem exactly as well. Changed the plugs, nothing. Regapped them: nothing. New coils: nada. The culprit was a bad fuel pump! Walbro 255 fixed this. Quote Link to comment Share on other sites More sharing options...
shadow Posted October 16, 2008 Author Report Share Posted October 16, 2008 I had this problem exactly as well. Changed the plugs, nothing. Regapped them: nothing. New coils: nada. The culprit was a bad fuel pump! Walbro 255 fixed this. Is this easy to install myself? Quote Link to comment Share on other sites More sharing options...
RareGMFan Posted October 16, 2008 Report Share Posted October 16, 2008 You'll have to lower the gas tank, and be careful not to break any of the old, brittle lines. Aside from that, it's a breeze. If you have access to a fuel gauge, I'd use that first to test and see if you need one in the first place. Quote Link to comment Share on other sites More sharing options...
shadow Posted October 16, 2008 Author Report Share Posted October 16, 2008 Thanks guys I am gonna have to think about having the dealer fix this soon. right now the car drives fine and its only noticable problem at WOT at the moment and I dont do that often Quote Link to comment Share on other sites More sharing options...
RareGMFan Posted October 16, 2008 Report Share Posted October 16, 2008 I drove my TSTE a loooong time that way. Just like you, so long as I didn't get into the throttle, it wasn't a problem, so I didn't worry too much about it. Start with the plugs. It's cheap, and it certainly couldn't hurt. A new set of wires isn't that expensive, either. Quote Link to comment Share on other sites More sharing options...
krenzy Posted October 16, 2008 Report Share Posted October 16, 2008 If you do end up upgrading the pump, I recommend NOT going the stock replacement route. Opt for the Walbro 255...very affordable. But just like RareGMFan said, taking into account the age and brittle factor of the line, it's easy. Oh and don't take it to a dealer to do it. You can save a TON of money and do it yourself. I'm not 100% mechanically inclined, but if I can do it, so can you. And if you REALLY feel uncomfortable doing it, find a local shop you trust, because the dealership WILL rape you. Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted October 16, 2008 Report Share Posted October 16, 2008 Before you go any further, be sure you have new plugs in the car that are gapped correctly, and be sure that you have good fuel pressure at the fuel rail. If you have good fuel pressure, you won't have to replace your fuel pump. Quote Link to comment Share on other sites More sharing options...
killinprixs Posted October 17, 2008 Report Share Posted October 17, 2008 check fuel pressure and for vaccuum leaks. i'd definately do a basic tune up, wires, plugs, fuel filter before i replaced any serious mechanical parts. TGPs need tune ups to run properly, they're very tempermental. Good luck. Quote Link to comment Share on other sites More sharing options...
shadow Posted March 25, 2009 Author Report Share Posted March 25, 2009 i sm going to finally try new plugs. Can a spark plug go bad all of a sudden like on a long ride home? Quote Link to comment Share on other sites More sharing options...
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