North American Turbocoupe Organization



need help, no boost at all on new T3
powered by turbo Offline
Member
#1
Hey all,

I'm trying to piece this car back together. I put in a T3 with a new center section. Long story short the car does not build any boost at all. absolutely zero.

Here is what I have:

- new T3 center section
- SVO compressor housing
- used turbine housing (minor cracks around the wastegate hole)
- used down elbow
- used WGA

Everything is installed and clocked up properly as far as I can tell. I had to pressurize the WGA to get it to set on the flapper (it was a little shy of the hole).

I hear the turbo whining a bit, but zero boost, and it feels like a dog.

-Timing is dead on
-vacuum stays at 18-20in
-with the WGA hose disconnected still no boost
-WGA operates with pressure from an air compressor (seems like it moves a good 1/2 inch)
-turbo shaft spins freely by hand
-all intercooler lines plumbed properly as far as I can tell

This is a strange sound, I've had intake leaks in the past and it doesn't sound like that. When I turn the car on it sounds, feels, and idles like it is running great.

Thoughts?
1986 Mustang SVO
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Forcedbird Offline
Member
#2
Maybe WG stuck open.
88 TC

HY 35, Ported Oval head w/OS valves, EEC Tuner, Bob's MOAL, .510 lift cam, Tial 38mm wastegate, K&N in fender, Kirban AFPR, Walbro 255lph fuel pump, 57 lb inj., GN intercooler, Gillis valve, Race eng. adjustable cam pulley, HKS SSQV BOV, Steeda Tri-ax shifter, 4" DP to 2 1/2" exhaust, no muffers, Timing set to 12* BTDC, 26 psi of boost. Needs to get tuned!

Proud to be a NATO member!
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powered by turbo Offline
Member
#3
What is a good way to check and see if it is stuck open?
1986 Mustang SVO
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ipsd Offline
Member
#4
Even if you had a hole in a hose you should be able to build some boost. To check the waste gate take the actuaor rod free and wire it shut an dgo for a ride. If it makes boost then it was open. But jsut to let you know I had a problem like this about 2yrs ago. In my car the cat was pluged up. I replaced just about everything. It would wrap up to 3500rpm then cut out. But if you did try and get on it it wouldn't make boost. I would idle fine and even run good as long as you didn't wrap it up. Finnaly I took it to a shop and they checked the Exhust back pressure with on of those push in compression testers in the O2 sensor hole. Had 18psi. So maybe yours is pluged but just not as bad. I know when we took it off at the exhust shop you could only see through 2 of the holes. So I guess you should check the exhust pressure like they did. Atlest then you would have some idea.
84 T/c, 88 intake,I/C, injectors, hood, PC1 ecu, E6 manifold, Brown Tops, K$N open element, BPV. Way pay to run 8 cylinders when 4 plus a turbo will get you there quicker.
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powered by turbo Offline
Member
#5
Hmm, that's an interesting idea, ipsd. The only thing that confuses me with your scenario though is that the car was working fine with the old turbo. Granted, I just got done replacing a headgasket, getting a valve job done and putting on this T3 turbo. But the IHI worked fine last week. I guess I can drop the exhaust and take a peek. I have seen stranger things.

What did they put in the O2 bung? A compression tester, like the kind you test cylinder pressure with? If so I can check that tomorrow. I will do that and also wire the wastegate shut to see if I build boost at all.
1986 Mustang SVO
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ipsd Offline
Member
#6
Yeah they used one of those push in style compressino testers. ALso that happend to me after I cracked a head it was smoking real bad. Maybe something got in the cat and dried in there that is what had to happen to mine it had only 10,000 miles on it when it happend to me. the car did sit for about a year but I couldn't find anything but carbon when I busted the ceramic thing out of it.
84 T/c, 88 intake,I/C, injectors, hood, PC1 ecu, E6 manifold, Brown Tops, K$N open element, BPV. Way pay to run 8 cylinders when 4 plus a turbo will get you there quicker.
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Jeff K Offline
Administrator
#7
If the problem started right after the new turbo install, I doubt the cat is the problem. Either the WG is open as others have said, or there is a problem with the turbo. Does it spin freely when you try to spin it by hand? Did you replace the oil feed line with a new one?

Easy "no tools needed" way to check for exhaust restrictions is to loosen the 2 nuts that attach the DP to the elbow, and drop the DP down a 1/2" or so, and go for a ride. If performance significantly improves, you have an exhaust restriction.
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
05 Taurus SEL Duratec daily driver
04 Taurus Duratec (wifes car)
02 Pontiac Grand Prix GT
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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powered by turbo Offline
Member
#8
Yep, the turbine spins freely, and makes absolutely no sounds that would indicate it is contacting the housings.

The oil feed is a braided line that was working on my IHI. I cleaned it out and blew compressed air through it before reinstalling it. I don't think that anything could be wrong with it. I also cranked the car 10-15 times on the new turbo before starting to prime everything.

The head just got back from the machine shop. It was magnafluxed, pressure tested, and given a full valve job. I don't think anything is wrong with the head itself.

I'm going to get to work on it in a bit.
1986 Mustang SVO
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powered by turbo Offline
Member
#9
JeffK, I checked your suggestions. I rechecked the oil feed line. I put it in an empty quart of oil and cranked the motor (w/no spark obv). It is indeed pumping oil.

I rechecked my cylinder compression (cold). I'm getting 140+ on all cylinders. I was getting only 110-115 on cyl 3 before the head work was done.

I dropped the dp down as far as it would go on the studs without falling. I didn't feel like that was enough of a difference, so I pulled the O2 just to be sure. On the test drive, it still won't build boost. But, the buzzing sound that it was making when I was trying to build boost before isn't happening with the exhaust dropped.

I'm going to have a beer and let the car cool down. Then I'll wire the wastegate shut. The only wire I have on hand is regular household 110 copper. I'll strip a piece of copper out and wire it shut with that. I'm assuming that should be more than strong enough to hold the WG shut. If it still does not work, it would appear that the turbo is dead. I believe I have exhausted all possible troubleshooting methods.

I have checked, double-checked, and triple-checked turbo to manifold bolt torque, and manifold to head torque. I have a new felpro gasket between the manifold and turbo.

I searched extensively and found a post in 2003 from Thndrchckn420 where he was having the exact same problem.

http://natomessageboard.com/ultimatebb.p...853#000000

I pm'd him and he said that the turbo was bad and had to be replaced. I got it from Aerobird, so we'll see what he can do for me in that case. Here's to hoping that it is just a WGA problem. I will know for sure in about an hour.
1986 Mustang SVO
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powered by turbo Offline
Member
#10
With the WG wired shut it still does not boost. It just makes a lot of noise. It's a whirring / buzzing noise. I cranked the copper wire down very tight with a pair of vice grips. It should have produced at least 1 psi if the turbo worked.

The turbo is shot.
1986 Mustang SVO
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