Need a 1g DSM turbo expert

Got a question that I was wondering if anyone could help me with. I'm having problems with the Turbo on my Talon, and while I know a fair amount about automobiles in general, I'm rather new to the turbo game. I have a 91 TSi 2.0 FWD Talon and she's acting like a pooch. If anyone can help, I'll be forever in your debt.

Originally, I was having a problem whenever the turbo would kick in. Anytime the turbo guage got above zero, the car would start to lunge and jerk. Kind of like the way a car does when a new driver is learning to drive stick. Whenever the boost isn't kicked in, she would run fine. But, the minute I got above manifold pressure, that's when the trouble started. Also, the idle was rather rough, especially after being driven for a while.

It was recommended that I search for a turbo system pressure leak. I have yet to do that, but I did find a vacuum leak on the line that hooks into the BOV. I fixed that, and now this. I'm not sure if I fixed one problem and this is another, or if this problem is just a different symptom of the same problem. Maybe a turbo leak causes this, too.

Okay, here's what's happening now: Instead of jerking and lunging, now the turbo won't even kick in at all. Well, barely, anyway. When I accelerate, the turbo guage stops at about 2 or 3 pounds of boost and will go no higher. When I'm driving, she runs fine, just no boost.

Also, idling is a huge problem. After driving for a while, anytime I approach a stop and disengage the clutch, she dies. When I try to start her, she doesn't want to fire unless I push the accelerator. If I feather the gas, she'll stay running, but dies if I don't.

One final thing of note and I'll stop this book. Sometimes when I try to start her after not driving her for a while, she doesn't want to run at all. She'll fire, but die immediately. Nothing helps this, except persistence. Feathering the gas doesn't make her run. If I keep the starter engaged, which I know is a horrible thing to do to a starter, she'll run, but dies as soon as I disengage it. After being persistent and restarting her dozens of times, eventually, she'll run, but then she runs like shit, doing what I told you about above.

If anyone can help, you'll be my hero!

Thanks
Jon

P.S. Don't get too technical on me. You don't have to put it in "Turbo for Dummies" terms, but don't go overboard. Like I said, I'm new to this game.

hey i'm kind of new to this as well but i know a little....

make sure your bov isn't venting to the atmosphere

make sure you have no leaks and also if your wastegate is functioning correctly.... might not be closing all of the way

put good gas in it.... the highest octane that you can find and run it through as there may be a fuel problem

also check normal maintanence such as spark plugs and wires and make sure all are good and connected good.....

if all is okay with this and you're still having the problem come back and let me know.... i can ask people that would know what's up.....

definatly check your plugs, wires, ect. have you looked at the internals of the turbo yet? make sure that the wheel isn't loose or tweaked. also, dsm's hate lo-grade gas, they run horrible on less that 89 octane. sounds like you have more than one problem though, one turbo related and one from maybe your ignition system. hope this helps :biggrin:

go to dsmtuner.com or buschurracing.com, just to let you know your bov can vent to the atmosphere. check vacuum lines and do a compression check. i highly recommend buschurracing.com. i have been a member there for over a year and the people there are very helpful very knowledgeable and if you have a turbo charged dsm your gonna need them a lot.

well you need to check you turbo stock boost regulator it sit right on top of your intake if one of those lines are off our leaking that will miss all sort of stuff up the next thing your temp sensor my be bad that would make your idel go crazy, or it could be your computer. when you computer starts to go bad it will run good some times and other times you wont start or evon want to run for you so i hope i gave you some ideas write back and tells us what you find out.

you mentioned black smoke that is a sign of running to rich aka to much fuel. i don't think that is the problem but ya never know. is the problem your turbo or something else? it just doesn't sound like a turbo problem. at least it doesn't sound like thats where its originating from. do you have any mods? you mentioned boost gauge, is it aftermarket or the factory one? the factory one is hella inaccurate. i recommend getting a gauge pod and getting a aftermarket boost gauge if you don't have one. i still HIGHLY suggest hitting up www.buschurracing.com. go to the tech forum. that is the greatest website that ever happend to dsms.

Quick update for anyone who cares. I think I've gotten to the bottom of the hard start problem. Pulled a plug and it was ridiculously black and sooty. Looks like the black smoke and unburnt fuel spitting out the tailpipe was caused by the car running too rich. Fouled the plugs out. I replaced them, and it fired up, no problem. But, it's still running crappy, so I still need to diagnose the turbo problem. I'm going to try and look for a boost leak tomorrow.

Question: Does a boost leak cause the computer to alter the fuel/air ratio? Would a leak cause it to run to rich? If not, how about the MAF sensor? It took a hell of a hit in the accident. If anyone can help with that, I'd appreciate it.

Thanks again.
Jon

Here's another update. I did a lead check on the turbo system last night. Haven't checked the MAF sensor as of yet. That's my next order of business. Wanted to ask a question before I move on. I wasn't able to check all of the lines in the turbo system for leaks. Reason for this was because I couldn't get the system to pressure up long enough. I've never done any of this, so I'm not sure what's supposed to happen. Whenever I'd pressure the system using my air bubble, I'd hear a hiss from the valve train for about five seconds. Then, all of the pressure would be gone. If I took off the oil filler cap, the noise would get louder.

Now, I'm not sure what this means. I'm guessing that what I'm hearing is the air leaking into the cylinders through whichever valves are remaining open when I shut the car off. Is it supposed to do this? If not, what can I do to stop this?

Thanks again to all who read this. Any help I get is greatly appreciated.

Sincerely,
Jon

have you checked for a vacuum leak yet?

Sorry, guys. Should've clarified just how I tried to pressure test the turbo system. I took off the outlet hose (the one between the turbo and the intercooler) from the turbo system and put a PVC cap in the hose. I drilled a hole in it and put a valve stem in it. I used an air tank to pressurize the system. I wasn't able to check the hoses, intercooler, BOV, and the like for leaks because I couldn't get the system to stay pressurized. Within seconds, I'd lose whatever pressure I put into the system through the valve train. I could hear the hiss for a few seconds from under the valve cover, and it got louder when I removed the oil filler cap. Not sure why this happened. I'm guessing that I lost the pressure through the valves that were open when I shut off the car. But, is this supposed to happen? Like I said, I'm new to this and I've never done anything like this before.

Oh, and I've yet to check for a vacuum leak. That'll be next.

Thanks again, fellas!
Jon

gotta delete some of these duplicate threads. im answering in all three cuz i dunno which you'll read. plug the intake at the throttle body too. also it sound like you may need to clean/replace your pvc valve

check the wastegate actuator rod. If it is not on properly then the wastegate will remain open and you will get no boost. It happend to me when i had my eclipse. Just look by the turbo for it

Okay, guys, time for a further update. I came to a revelation last night. So, today, I'm putting the boost leak check on hold. Remember when I said that after I changed the plugs, I got her to run, just not very well? Well, last night, I started her and tried to take her for a spin. I couldn't get her to go anywhere. She would not stay running. So, I took the suggestion of more than a few people and I disconnected the Mass Airflow Meter (the one in the air cleaner cannister). While I was at it, I disconnected the battery for a few minutes to reset the computer, thinking maybe that would reset the fuel/air mixture. When I reconnected the battery and started the car, it ran. Not very well, but it ran. So, I'm thinking, "Cool. I just reset the fuel air mixture", and took her for a spin, albeit a very rough spin. I drive a few blocks, then pulled over to reconnect the MAF Meter. I popped the hood and reconnected the plug, then tried to restart her. I was right back where I started. She wouldn't stay running at all. She'd fire and die instantly. So, I disconnected the MAF Meter, and drove her back home.

Here's another oddity of that situation. I replaced the Idle Speed Control a couple of months ago because it was chattering at me like a chipmunk when the key was on but the car wasn't running. I was thinking that was the reason that she was running so crappy. That didn't fix the problem, though. The new one I put on still chatters. Well, I hadn't noticed at the time, but last night when I disconnected the MAF Meter, the ISC stopped chattering. When I plugged it back in, I noticed that the chattering had been gone and came back when I plugged the MAF Meter back in. So, after a series of disconnects and reconnects of the MAF Meter, sure enough, whenever it was unplugged, the ISC was quiet. Whenever it was plugged in, the ISC went crazy.

So, what does that sound like to you? MAF Meter's bad, right? Couldn't just be caused by a vacuum leak, could it? I'm going to alleviate any possibility of that tomorrow. I'm going to go buy a spool of vacuum line and replace all of them. Not just because it's running bad. After 13 years, I'm sure it'll do the car some good. I'm going to go to my donor car today and grab the MAF Meter off of it. Not sure if that'll fix it, though. The reason I say that is because the outer housing of the air cleaner cannister on the donor car is missing. So, that MAF Meter has been blowing in the wind for God knows how long. I'm sure that one's bad. But, for free, it can't hurt to give it a go. If anybody has any other ideas for me or wants to confirm my suspicions, I welcome any comments. I'll keep you posted as to what I come up with.

Thanks for everybody's help.
Jon

I'm not going to be updating this post any longer. It's rather old, and some people are getting upset about the presence of multiple posts about what is essentially the same problem. I am, however, going to keep three identical posts for the three types of cars that are essentially the same, those being the Laser, the Eclipse, and the Talon. So, if you have any questions for me or want to offer any help, can you post it to one or all of the following posts:

Laser: http://www.automotiveforums.com/vbulletin/showthread.php?t=231451
Eclipse: http://www.automotiveforums.com/vbulletin/showthread.php?t=231452
Talon: http://www.automotiveforums.com/vbulletin/showthread.php?t=231450

I appreciate you checking this post, though. If you've got any help for me, write it up on one of those other posts. I'll get it that way.

Thanks again for helping me.
Jon

Okay, we can close the book on my problems, once and for all. I've finally gotten my Talon back in working order. Turns out my problems were twofold. I ended up having a bad turbo and a bad ECU. Replaced the turbo first, and that got rid of the jerking. It was still running rich, though. Then, over the course of the last few days, I came to the conclusion that my ECU was shot. So, yesterday I pulled one out of another car and put it in. She started right up. So, I'm rolling again, and it's in no small part to all you guys that helped me out on this website. Thanks for everything. You guys saved me.

Jon