Lack of boost/surging

Q&A regarding engines, turbos, and intercoolers and power upgrades

Lack of boost/surging

Postby Killerguppy » Sun Aug 29, 2004 8:12 pm

My alltrac is having problems producing boost, it takes forever to build up and when @ around 5 PSI or more surges :doh:
Any suggestions?
Thanks
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Postby -==L=a=N=c=E==- » Sun Aug 29, 2004 9:14 pm

Check all your piping between the turbo and the intake. Sounds like a leak.

Else check for vaccum leaks.
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Postby Killerguppy » Mon Aug 30, 2004 1:09 am

I checked all the piping...I don't seem to have any leaks...Where else could leaks be that would cause this? Could the oxygen sensor be part of my problem?
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Postby -==L=a=N=c=E==- » Mon Aug 30, 2004 10:23 am

Killerguppy wrote:I checked all the piping...I don't seem to have any leaks...Where else could leaks be that would cause this? Could the oxygen sensor be part of my problem?


you got a boost gauge obviously. What is it idling at?

A good Idle is at 20HG/In

I had the exact same problem, it ended up being a busted vacuum line. Replaced it. and voila. I also had intake leaks as well. Double check everything.

O2 sensor woulnd't stop you making boost though. If you really want to double check, pull the error codes from your ECU
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Postby RIalltrac » Mon Aug 30, 2004 2:48 pm

whats forever? where are you in the rpm range? lag usually lasts up to 3grand or so on the rpm side of things. After that the car kinda gets up and goes. could be a clogged up cat as well, holds you back a bit.
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Postby Gary » Mon Aug 30, 2004 3:32 pm

Also, check for the shaft play on the turbo.
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Postby Stubble » Mon Aug 30, 2004 3:50 pm

O2 sensor won't affect boost, because it is ignored by the ECU at wide open throttle. I agree with checking for vacuum leaks, especially if this low boost problem came along suddenly. If it is a chronic problem that has been getting worse, I'd check your cat converters, especially the primary one (in the down pipe). If these clog, your turbo will spool slowly and will not make full boost.
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Postby alltracman78 » Mon Aug 30, 2004 10:41 pm

Don't forget about the wastegate....
Just to throw something else in there. :D

And check your ignition timing
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Postby ___Scott___ » Tue Aug 31, 2004 3:18 pm

If there are no leaks anywhere, then it sounds like a clogged cat to me. I had the same problem years ago. Gutted it, problem solved. :D
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