Need help for all you turbo guys!

[jon1197]

Ok, I have a 91 dodge Stealth r/t I got in a trade well I put it in the shop it had a bad exhaust leak and turbo was lagging at around half boost, so the guy calls me and said he couldn't fix the exhaust leak cause it's a braided steel cable under the motor causing it and I got a bad turbo on back side of motor.

I've never heard of a braided steel cable under the engine and also may I ask where is everybody getting your turbos at I'm leaving it stock cause I'm plan on getting rid of it but need it in atleast perfect running condition I know turbos are high but surely there has to be some cheaper just to get it going well enough to get it gone.

[binaryterror]

More than likely the leak is in the flex coupler in the pipe. Added to allow some wiggle, however they do fail.

Any muffler shop sould be able to remove and replace that section with either hard pipe or another flex section.

Finding old used and still good Dodge Turbos is tough. I suggest you head to the DSM forums and learn what turbo it uses and what might replace it. Additionally you can try junkyards or Car-Part.com--Used Auto Parts Market

[STANG KILLA SS]

correct. its flexible exhaust "tubing" looks like steel rope.

[ozyint]

Originally Posted by jon1197

Ok, I have a 91 dodge Stealth r/t I got in a trade well I put it in the shop it had a bad exhaust leak and turbo was lagging at around half boost, so the guy calls me and said he couldn't fix the exhaust leak cause it's a braided steel cable under the motor causing it and I got a bad turbo on back side of motor.

I've never heard of a braided steel cable under the engine and also may I ask where is everybody getting your turbos at I'm leaving it stock cause I'm plan on getting rid of it but need it in atleast perfect running condition I know turbos are high but surely there has to be some cheaper just to get it going well enough to get it gone.

Buy a stock one out of the junkyard. Pull it out and look at the turbine make sure there isnt any chips or nicks in it and that the shaft doesnt have any play in it. Shouldnt be more than $40 or so.

[Draggermirage]

Those are Mitsubishi Heavy Industries (MHI) TD04H 9B turbos on the Dodge Stealth. They are identical to the Mitsu 3000GT setups in every way.

The flex section is probably what is leaking in the exhaust system and *can* be replaced, but you'd probably be better off finding used replacements as they typically don't go bad. Ebay, craigslist, local DSM and 3si forums are your best bet. The same goes for a stock turbo. A lot of people pull the stockers in favor of a pair of larger turbos for a better powerband.

Most typical muffler shops tend to build system parts that don't fit as well as the factory pieces or last as long. Not to mention they look like crap. Another option is to find an aftermarket downpipe (available from several online vendors and get the stock exhaust modified to mate up with the new pipe.

If you truly need a replacement turbo, if I remember right, you will need to pull the engine or bare minimum the cylinder head. I haven't done a straight turbo swap on one, but have done other major work to these. I'd be inclined to say that your issue isn't a turbo if it is still in good condition. Most likely it will be closer towards a boost leak, failing MAF or misfires. Boost leaks and misfires being the more common problems. Obviously I'm shooting in the dark without knowing it's behavior.

Hope this gives you a little bit of a direction.

Marcus
Jacking with Mitsu performance for almost 14 years.

[jon1197]

The car runs fine, boost is good til about half boost than it cuts out very badly as long as you ease into the throttle motor itself is runs fine see he didn't take the turbo off I asked so idk how he said it's bad without viewing it himself I got the car from a older fella and he said he just a bunch of new parts on the car but boost was messed up and he couldn't figure it out, so I figured I would try but I have no clue with turbo cars, the shop did put new plugs and wires in and fixed my air intake it had a bad habit of popping off and would not say on even with a new rubber intake tube that connects to my throotle body and the plastic air intake itself, hope this helps better I know it's hard to completely understand since your not right in front of the car

[romulus22]

What do you mean it cuts out badly? Stops producing boost? Stops producing power and the car feels like it's shutting down? What psi is the turbo peaking at before it's "shutting down"?
From hearing the words cut out it makes me think your talking about the car running out of fuel under boost. The car can have a bad exhaust leak. After the turbo causing no problems. Before the turbo could cause low boost but not cause it to cut out. Even a bad turbo with shot bearings will still produce boost. Trust me I know from my own car.
Try to explain what the car is doing when it's cutting out. Sounds to me like a fuel pump going out and the shop you took it to has no idea what they are doing.

[Ernie W]

Also being the owner of one of these car, I've got a 1992 Mitsubishi 3000GT VR-4. I suggest you look on www.3si.org or www.3sgto.org

If the turbo is bad, you can pick up a used set of turbos cheap. There are a couple vendors on there that offer rebuild services such as.... Midwest Turbo Connection, Turbo Restoration, Turbo Upgrade, & Turbo Parts Sales 715-690-9262

If the downpipe has a busted flexpipe, it would be easier to buy an aftermarket piece. You can pick them up cheap also. Or just have a new flex welded back in place of the old.

If you need parts or anything, you can check out
www.3sx.com
www.ipsmotorsports.net

As with the misfires, as mentioned, these cars are bad for boost leaks. Way too many vacuum lines running around.

They have all sorts of odds and ends.

[jon1197]

Yes sorry, it shows it runs almost 14 pounds of boost right ' dont know how true that is i could be reading it wrong also 'at half the car cuts out but sounds the turbo was cutting maybe that's because of the car trying to pick up and go to create bost maybe? Sorry for the miss understanding I got this going on plus where packing up to move which sucks but yes power cuts out at right half boost everything that's when eased into throttle if I give it hell right off the bat it cuts out right then

[romulus22]

I could be wrong but 14psi sounds high for not being set up to do so. To me it still sounds like your having fuel problems. Possible a stuck waste gate and your fuel cant keep up? Have someone hook up a fuel pressure gauge to the fuel rail and see what psi you have while idling and while driving.

Ide like to help more but its so hard to read what your trying to say its just aggravating me. Good luck with it

[Ernie W]

Yea, the stock gauges lie. The 91-93 turbo 3S cars pushed about 8-9psi stock. The 94-99 3S pushed 11psi. Sounds to me like a bad boost leak, either that or its not getting the fuel it needs.

[Draggermirage]

Do not rely on the factory boost gauge. It is NOT accurate. It's only an estimation using numbers from the airflow meter, RPM, throttle position and a few other readings. It's relatively accurate, but not enough to diagnose the car by.

I highly doubt it's a fuel pump for a couple reasons.

1) These pumps are made by Denso. I have NEVER seen one "partially fail" with lower flow or pressure. They simply shut off never to turn back on again (or at least without a sharp whack).
2) The car would feel flatter than normal during WOT before it misfired. Not at half throttle or anywhere in closed loop. If it cuts out like you hit a brick wall while still having the pedal pegged, look elsewhere. It's not a fuel pump.


Save yourself the money with wasted parts and wasted time. Find someone who knows these cars and have them diagnose it.

The more you describe it, the more it sounds like a boost leak. Check every clamp and hose. Not just visually either. Grab ahold of each one and give it a good yank. If it moves or a hose tears or you found a hole, then I can guarantee you just found your problem. An even better method would be to pressurize the intake tract to at least 20-25 psi and listen for the leaks around the engine bay.

The car has a "ceiling" in airflow readings that it will accept before it cuts fuel completely in an effort to save the engine in the event of a perceived "overboost" condition. This overboost condition will only happen on a stock car for a few reasons.

An intercooler hose or clamp is leaking air.

Injector seals or intake manifold gasket badly blown out.

Overactive MAF.

Too high of boost pressure/airflow.

Marcus

[jon1197]

Yea I can check hoses myself but I will look around and check if anybody has experience with these cars cause it's the only I've seen I had to take my intake off to change my back 3 plugs and wires so I put it in the shop for that the exhaust leak ' cause it sounds horrible ' and the boost was thrown off and I heard from someone talking about a wastegate could be sticking open or something in that matter but I'll most defintaly check my hoses clamps and all of that

[Nabil]

I would listen to draggermirage. Everything he has said is 100% accurate. When a turbo goes bad you will hear it and know. Plus iirc the older dsm cars used oil cooled turbos, so lots of blue smoke and disappearing oil would occur

[jon1197]

Oh for sure it does make sense 100% and thank you for all the response I'll check back in when I figure something out and thanks again fella's

[Tedro]

Sounds like a boost leak, there's video on youtube.com on how to make a boost leak tester. search for "boost leak tester". or you can just check your vacuum lines like Draggermirage said...

[ClassicGMJunkie]

a cheapo one-man brake bleeder boost/vac pump can be a good tool to pressurize the lines and listen for a leak and check the gauge for pressure loss. hell back in my turbo days we would use a Dwyer gauge for checking PSI drops in pipe runs and FMICs.

don't fear turbo work, its not all smoke and mirrors. simple hand tools can make you dangerous enough to change out a CHRA from a limping turbo and be back on the road with minimal down time.

although I have heard its a MOFO to work on them engines, they can make owners very happy when running right.

[STRATTON]

Originally Posted by jon1197

The car runs fine, boost is good til about half boost than it cuts out very badly as long as you ease into the throttle motor itself is runs fine see he didn't take the turbo off I asked so idk how he said it's bad without viewing it himself I got the car from a older fella and he said he just a bunch of new parts on the car but boost was messed up and he couldn't figure it out, so I figured I would try but I have no clue with turbo cars, the shop did put new plugs and wires in and fixed my air intake it had a bad habit of popping off and would not say on even with a new rubber intake tube that connects to my throotle body and the plastic air intake itself, hope this helps better I know it's hard to completely understand since your not right in front of the car

ok. first things first, your coupler on your intake tube that connects to the throttle body keeps blowing off because a. the clamp was loose or bad or b. the coupler itself has dried and is brittle and is coming apart. a new coupler and t bolt clamp or worm clamp is 20 bucks at most.

have a broken flex pipe will not give you boost issue, it is nothing more then an exhaust leak. an exhaust leak on the exhaust side will not cause any issues other then noise or smell. the last restriction in a turbo set up should be its exhaust housing. on many oem turbo motors they tend to run small or smaller o2/jpipes, this may be a restriction but when it comes to performance everyone runs a larger o2/jpipe and or down pipe. agian an leak after the turbo will not cause a loss in boost.

boost is created by the exhaust gases, boost is controlled by the waste gate. the waste gate is controlled by a spring and vaccum, its a diaphram thats attached to a flapper inside of the turbo. waste gate has two functions a. controls how much boost created and send threw pipe/ic/tb and into the motor b. bleeds off excess psi (boost) out into the exhaust system to keep the pressure at a safe constant level.

the issue your are expriencing sounds like your waste gate hose could be cracked lowering the reading from were ever it gets it from (vaccum). so it could be a vaccum leak.

you could be expriencing a waste gate spring that over time has become soft and lets to much exhaust out lowering the out put of psi (boost).

you could be loosing psi thew another cracked, loose coupler on either the intake side of the pipes or the pressurised side of the pipes.

a bov (blow off valve) that has gone bad could also be bleeding off psi (boost). so check to make sure your bov is sealing tightly.

same can be said for the intercooler (if this car has one) there may be a hole in the ic itself etc.

you can find out alot by pressurizing the system. make a coupling with a air tank filler and pressurize it from the tb side. so basically you want to pressurize the pipes and intercooler. (all parts can be pieced out at your local homedepot or lowes). pressurize the system and find out were the air is going.

but agian your not loosing pressure because of an exhaust leak in the flex pipe. that is unless your turbos are twined together by a steel or cast piece that has a flex in it. either way a leak on the true exhaust side wont effect boost.

hope i havent confused you.

if you need any more help just ask. ive built 3 turbo motors, a few all motor setups etc.

stratton.

[STRATTON]

Originally Posted by ClassicGMJunkie

although I have heard its a MOFO to work on them engines, they can make owners very happy when running right.

one of the first places i ever dynoed one of my motors was pampino motorsports. the owner had the highest whp 3000gt (mitsu equivilant to the stealth) in the world. it made 1200whp iirc and this was close to 10 years ago.

stratton.

[opek]

Originally Posted by ozyint

Buy a stock one out of the junkyard. Pull it out and look at the turbine make sure there isnt any chips or nicks in it and that the shaft doesnt have any play in it. Shouldnt be more than $40 or so.

And by play he doesn't mean side to side, he means in and out!