no1kicker Posted February 20, 2005 Report Share Posted February 20, 2005 This is a slightly long post. Hope you don't mind reading. :? My car has has a boosting problem. When it started about 2 weeks ago, it would not boost at all. It happened suddenly. On the way to work it was great, leaving it felt like a vacuum hose had popped off, no boost. It ran great at low rpm's below boost. Idle was slightly unsteady. I checked for loose connections. All the vacuum hoses and turbo piping was good. I tried bypassing the boost control soleniod, no change. Disconnected the vacuum hose at the turbo outlet, it boosted a little. Zip tied the wastegate shut, that made it boost fast, but it fell off even faster. I believed the cat was plugged up. So today I cut it off and replaced it with straight pipe. The car idles much better. Power is better, but not 100%. Boosts a bit more now, but still has hesitation around 3000 rpm. Then after that it boosts slowly, and shifts really hard. I can hear the turbo working, just don't feel it that much. Now I'm stumped. The plugs and wires are less than a year old. Could they be the cause? Coils are 3 years old. As of now the car is normal up til the point of making boost. Then it hesitates, and boosts slowly. Any suggestions will be very appreciated. :? Quote Link to comment Share on other sites More sharing options...
Guest TurboSedan Posted February 20, 2005 Report Share Posted February 20, 2005 bad MAP sensor? Quote Link to comment Share on other sites More sharing options...
no1kicker Posted February 20, 2005 Author Report Share Posted February 20, 2005 That is a possibility. Any idea how I could test it, or is it replace and see? Quote Link to comment Share on other sites More sharing options...
Guest TurboSedan Posted February 20, 2005 Report Share Posted February 20, 2005 are you getting any codes? make sure it is plugged in. Quote Link to comment Share on other sites More sharing options...
no1kicker Posted February 20, 2005 Author Report Share Posted February 20, 2005 I'm not getting a SES light. Everything looks like it's plugged in. I checked the hose at the MAP today and it was fine. :?: Quote Link to comment Share on other sites More sharing options...
GP1138 Posted February 20, 2005 Report Share Posted February 20, 2005 I think you can tap the MAP sensor, and if it's bad, the engine will stumble. Quote Link to comment Share on other sites More sharing options...
god910 Posted February 20, 2005 Report Share Posted February 20, 2005 I think you can tap the MAP sensor, and if it's bad, the engine will stumble. Werd, I'd also look at your plugs, see what they look like. I had a stumble ended up being coils. Don't rule out injectors, boost makes them work, and injectors make boost. If they are failing, you would get slow boost (or it won't run at all) and the higher the boost, the more they have to pulse. Quote Link to comment Share on other sites More sharing options...
no1kicker Posted February 20, 2005 Author Report Share Posted February 20, 2005 How do you tap the MAP sensor? Tonight, the car had more power. Car runs great until 3000 rpm. Then it stutters, and the car has decent boost after that. Maybe 85% of what it's supposed to be. Would that rule out injectors or no? Quote Link to comment Share on other sites More sharing options...
GP1138 Posted February 20, 2005 Report Share Posted February 20, 2005 Fuel filter? Pump? Intake restriction? The map sensor is that rectangular box at the rear of your intake plenum. Tap it with your fingernail, or a screwdriver. Just tap on it, lol. Quote Link to comment Share on other sites More sharing options...
no1kicker Posted February 20, 2005 Author Report Share Posted February 20, 2005 So I just hit it? Thought "tapping it" was some special procedure. I have smelled gas for a bit after driving the car, for a long time. Smells like I was running a little rich. I assumed it was cause of the crossover, all of them are a bit cracked. Quote Link to comment Share on other sites More sharing options...
GP1138 Posted February 20, 2005 Report Share Posted February 20, 2005 So I just hit it? Thought "tapping it" was some special procedure. I have smelled gas for a bit after driving the car, for a long time. Smells like I was running a little rich. I assumed it was cause of the crossover, all of them are a bit cracked. I was a tiny bit unclear on how you "tap". I was hoping you hadn't drilled a hole in your MAP sensor, but I know you're not a moron. Maybe your crossover got worse? Quote Link to comment Share on other sites More sharing options...
GutlessSupreme Posted February 20, 2005 Report Share Posted February 20, 2005 Maybe your crossover got worse? That might explain it, though I'd think it'd be noticably cracked if you're not boosting well. Quote Link to comment Share on other sites More sharing options...
no1kicker Posted February 20, 2005 Author Report Share Posted February 20, 2005 Hmm, I hope it didn't get worse. :? The car's not stalling, and there's not that "rust" look around the pipe. I pulled a plug today and it looks normal except deposits around the edge. Maybe tomorrow I'll pull a few more. Here's a pic: I also cleaned the TPS connector and reset the ECM, maybe that will help. Also going to run some fuel system cleaner through. Thanks for the suggestions. Quote Link to comment Share on other sites More sharing options...
TurboGTU Posted February 21, 2005 Report Share Posted February 21, 2005 fuel pressure? Quote Link to comment Share on other sites More sharing options...
Guest TurboSedan Posted February 21, 2005 Report Share Posted February 21, 2005 fuel pressure? good idea! check that before you buy any parts... Quote Link to comment Share on other sites More sharing options...
twalt13 Posted February 24, 2005 Report Share Posted February 24, 2005 Greg, Have you ever run some of the GM "top end cleaner" through your car? You would be suprised how much smoke & crap comes out after doing this. High end studder is lmost always a coil / igition issue. HTH Quote Link to comment Share on other sites More sharing options...
GutlessSupreme Posted February 24, 2005 Report Share Posted February 24, 2005 Wouldn't be a bad idea^ We tried the MAP from my car last night, that wasn't it. Still ran the same. He grabbed the coils off my car and is going to try to swap them when he can. Greg, even thought it's looking like that's the issue, I'd grab a spark checker and go through all the cylinders one by one, have someone watch them at idle and under load, just to see if anything's irregular. I'd put it on the coil end of the wires just so you don't have to try getting to the rear plugs. Quote Link to comment Share on other sites More sharing options...
93CutlassSupreme Posted February 24, 2005 Report Share Posted February 24, 2005 So I just hit it? Thought "tapping it" was some special procedure. so is "hitting it" Quote Link to comment Share on other sites More sharing options...
Bossman429 Posted February 24, 2005 Report Share Posted February 24, 2005 Have you ever run some of the GM "top end cleaner" through your car? I always heard that this is a bad idea on a turbo car, because it sends all that shit, and carbon through the turbo's turbine wheel. Unless someone can verify otherwise... I did run some intake cleaner on the beretta, and it did seem to run a little smoother afterwards. Quote Link to comment Share on other sites More sharing options...
no1kicker Posted February 25, 2005 Author Report Share Posted February 25, 2005 I've never run any top end cleaner. Wouldn't be a bad idea, as long as it's safe for the turbo. But I think I remember reading something about Ty/Sy guys using it, so it has to be safe. I grabbed a spark tester today. And some new plugs, those are going in regardless. I looked for a fuel pressure tester today but nobody rents one. Thanks again for the suggestions, trying to get this fixed for dyno day Sunday! Quote Link to comment Share on other sites More sharing options...
Guest TurboSedan Posted February 25, 2005 Report Share Posted February 25, 2005 I looked for a fuel pressure tester today but nobody rents one. just piece one together at NAPA. that's what we did (my brother and i that is). just make sure you get a liquid filled gauge. we didn't and the needle vibrates too much although it still works ok. if you don't want to piece one together http://www.fwdperformance.com has a nice one for $65 (it would work just fine for our engines too), but you could make your own for less. as far as the GM TEC goes, i wouldn't be afraid to use it. it's not like you're going to blow a chunk of aluminum loose or something and i doubt the carbon buildup or whatever else could hurt the turbine anyway. Quote Link to comment Share on other sites More sharing options...
GutlessSupreme Posted February 25, 2005 Report Share Posted February 25, 2005 Have you ever run some of the GM "top end cleaner" through your car? I always heard that this is a bad idea on a turbo car, because it sends all that shit, and carbon through the turbo's turbine wheel. Unless someone can verify otherwise... I did run some intake cleaner on the beretta, and it did seem to run a little smoother afterwards. People have said that, but how exactly would it get to that point unless someone sucked it through the air filter or somewhere else before the turbo? it would most likely get sucked straight into the plenum, avoiding the turbo all together. Actually.. I guess shit does get in the oil.. just do an oil change very soon afterwards. Quote Link to comment Share on other sites More sharing options...
skalor Posted February 25, 2005 Report Share Posted February 25, 2005 You're actually supposed to change the oil right away after using the Top Engine Cleaner. I think it even says so right on the can. Quote Link to comment Share on other sites More sharing options...
Guest TurboSedan Posted February 25, 2005 Report Share Posted February 25, 2005 Have you ever run some of the GM "top end cleaner" through your car? I always heard that this is a bad idea on a turbo car, because it sends all that shit, and carbon through the turbo's turbine wheel. Unless someone can verify otherwise... I did run some intake cleaner on the beretta, and it did seem to run a little smoother afterwards. People have said that, but how exactly would it get to that point unless someone sucked it through the air filter or somewhere else before the turbo? it would most likely get sucked straight into the plenum, avoiding the turbo all together. Actually.. I guess shit does get in the oil.. just do an oil change very soon afterwards. because whatever air the compressor shoves into the plenum is going to end up going through the turbine shortly afterwards! before the air filter is not an issue...the filter will stop any debris and that's before (upstream) from adding the GM TEC anyway. if the GM TEC cleans & burns off MASS amounts of carbon buildup in the engine i suppose that might damage the turbine, but i seriously doubt it. and yes it's definately a good idea to change oil & filter and also spark plugs after using GM TEC. Quote Link to comment Share on other sites More sharing options...
GutlessSupreme Posted February 25, 2005 Report Share Posted February 25, 2005 *duh* lol I clearly didn't think about that :oops: it'd probably be a good idea for me to do while my turbo's off... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.