Bucking...no boost leak

[turbo3000dsm]

I had a boost leak with the throttle body gasket and BOV. I fixed them both and still have bucking under boost, all of this is sudden, and weather sometimes effects it. It sounds like a backfire and bucks. EGT's don't get high and vacuum sits low.

 

[oldman]

I had a boost leak with the throttle body gasket and BOV. I fixed them both and still have bucking under boost, all of this is sudden, and weather sometimes effects it. It sounds like a backfire and bucks. EGT's don't get high and vacuum sits low.

How many psi did the system hold for at least 45 sec before you decided the leak test was complete?

 

[turbo3000dsm]

I tested it at 20 but doesn't hold long but will hold 11 psi for about 30-40 sec. I can't drive the car right now to check and see if its fixed... but should find out very soon.

 

[oldman]

I tested it at 20 but doesn't hold long but will hold 11 psi for about 30-40 sec. I can't drive the car right now to check and see if its fixed... but should find out very soon.

That usually means there are more leaks to be found. Make sure you disable the mbc for the pressure test, there is a bleeder hole on most mbcs. Also open the oil cap during the test and see if you hear air leaking into crank case.

 

[oldman]

Also check the plugs and wires. Is the car smoking?

 

[turbo3000dsm]

I checked the plugs and they are fine and the wires barely have 500 miles on them. When I try to launch it my friends say it looks to be running rich and smokes when it backfires... I also have the leak at the throttle body that I just can't seem to fix, any suggestions. Thanks for the help oldman

 

[turbo3000dsm]

I started the car today and left it in neutral and reved it a couple times. It still has the sputter with no load and smokes when it sputters.

 

[oldman]

You're welcome.

I also have the leak at the throttle body that I just can't seem to fix, any suggestions.

If you have already tried the soapy water technique I would say it's either the biss screw o-ring or the tb shaft seals.
http://www.vfaq.com/mods/BISS-1G.html
http://www.ca.dsm.org/faq/tb-shaftseals.html

When I try to launch it my friends say it looks to be running rich and smokes when it backfires...

It's clear you're running rich, question is why? Take it easy with it until you figure this out.

any suggestions

1. Complete the boost leak test, 20 psi for at least 30 seconds. Remember to open the oil cap and listen.

2. I think it's time for a compression test so we don't leave anything out. http://www.dsmgrrrl.com/FAQs/compression.htm

3. Follow the service manual and measure the ignition coils and make sure everything is proper.

Have fun.

 

[turbo3000dsm]

Thanks I think thats what the leak is with the Thottle shaft seals. I will take apart the Thottle body today and look to see if thats the problem.

 

[turbo3000dsm]

I took apart the throttle body and replaced the seals. Went for a ride today and car did it again? Until the EGTs got hotter and the car warmed up. Still a boost leak? Could a exhaust leak cause this? Please help... going crazy

 

[oldman]

1. Complete the boost leak test, 20 psi for at least 30 seconds. Remember to open the oil cap and listen.

2. I think it's time for a compression test so we don't leave anything out. http://www.dsmgrrrl.com/FAQs/compression.htm

3. Follow the service manual and measure the ignition coils and make sure everything is proper.

Relax and take it one step at a time.

 

[turbo3000dsm]

I finally found it..... It wasn't a boost leak. What it turned out to be was my ECU. It looked real crappy about 2 months ago and I forgot about it. I got a real $$CHEAP$$ ECU, and put it in and bam. The car runs like it should, thanks for everyones help.